Previous Thread
Next Thread
Print Thread
Page 1 of 6 1 2 3 4 5 6
Shock Tech #931968
02/18/11 07:49 PM
02/18/11 07:49 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Ok guys. Let's get it going here.....

If we look at the question; "The car hooks then spin, or rear tire wads really bad from too hard of a hit to the tires?

Consider that the rear suspension typically goes into extension and the foot print (of the tire) gains weight as the housing travels toward the track. The side walls become loaded and apply downward force to the foot print. If we apply too much downward force, the tire will bounce. It is like a basketball. The harder you dribble the ball, the more it will want to return to your hand. Hit the tires too hard, they hook, wad up and then when the tire becomes round again-it will want to return to it's original shape and as the sidewall un-wads, it pushes up. That pushing up condition will relieve weight from the foot print causing wheel spin. It may be slight but it only takes a little amount. (One way this event shows up is if you see a car stretch out the front suspension as it leaves, then set the front end down only to pick it up again, it did the hook/spin deal and wadded the tires too much..

Consider a potential fix is to stiffen the extension of the rear shocks. Slowing down the separation and the extent that the rear housing (with it's mass) is traveling toward the track will result in planting the tires just enough to hook the car. Also, consider we only need enough traction to hook the available torque traveling down the driveline, thru the axles and to the rims/tires.

If you have a double adjustable shock, you can also stiffen the compression to help hold the tire down, slow the rebound effect and keep the weight at the foot print from being relieved too quickly.

There are other potential fixes too. Some aren't shock related...

Anyone have seen this before? Anyone driven a car that felt like this?

Re: Shock Tech [Re: EricatAFCO] #931969
02/18/11 08:21 PM
02/18/11 08:21 PM
Joined: Feb 2003
Posts: 3,998
GO BUCKS !!!!!!!
3
340RICK Offline
master
340RICK  Offline
master
3

Joined: Feb 2003
Posts: 3,998
GO BUCKS !!!!!!!
Nice to see you join the gang Eric

I have seen this plenty of times as you stated.

I put a pair of AFCO Big Guns on the back of the car.

Compression is at 3 clicks from soft
Extension is at 8 clicks from soft

Car has very minimal body seperation just slight wrinkle in tire and pulls the front wheels up nicely.

I had to tighted up the extension to achive this

Re: Shock Tech [Re: EricatAFCO] #931970
02/18/11 08:23 PM
02/18/11 08:23 PM
Joined: Jan 2003
Posts: 32,394
Q
Quicktree Offline
I Win
Quicktree  Offline
I Win
Q

Joined: Jan 2003
Posts: 32,394
can we get a sticky for this thread

Re: Shock Tech [Re: Quicktree] #931971
02/18/11 08:40 PM
02/18/11 08:40 PM
Joined: Jan 2003
Posts: 32,394
Q
Quicktree Offline
I Win
Quicktree  Offline
I Win
Q

Joined: Jan 2003
Posts: 32,394
thanks for the sticky

I would like to know the difference in shocks, how they work, what makes one better than another, how effective the different types are etc

Re: Shock Tech [Re: EricatAFCO] #931972
02/18/11 08:43 PM
02/18/11 08:43 PM
Joined: Oct 2004
Posts: 1,752
detroit area
M
moderncylinder Offline
top fuel
moderncylinder  Offline
top fuel
M

Joined: Oct 2004
Posts: 1,752
detroit area
ive always been told you run compression tight and extension loose,,, when starting off would you run in the middle of your adjustments or bias it one way or the other? how about compression 1/4 way between, bias toward being hard,, and ext in the middle?? or???

Re: Shock Tech [Re: moderncylinder] #931973
02/18/11 08:50 PM
02/18/11 08:50 PM
Joined: Jan 2003
Posts: 999
British Columbia
T
toddd Offline
super stock
toddd  Offline
super stock
T

Joined: Jan 2003
Posts: 999
British Columbia
Thanks for coming aboard.

Re: Shock Tech [Re: EricatAFCO] #931974
02/18/11 08:52 PM
02/18/11 08:52 PM
Joined: May 2006
Posts: 1,072
oregon
G
greendart408 Offline
super stock
greendart408  Offline
super stock
G

Joined: May 2006
Posts: 1,072
oregon
I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.

Re: Shock Tech [Re: toddd] #931975
02/18/11 08:55 PM
02/18/11 08:55 PM
Joined: Oct 2003
Posts: 2,537
PORT ALBERNI , BC., CANADA
superwrench Offline
master
superwrench  Offline
master

Joined: Oct 2003
Posts: 2,537
PORT ALBERNI , BC., CANADA
Yes Todd, this should be a good learning session as my car likes to unload the tires just as described.
Maybe I'll be buying some better rear shocks!!!

Re: Shock Tech [Re: superwrench] #931976
02/18/11 09:18 PM
02/18/11 09:18 PM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back

Re: Shock Tech [Re: joshking440] #931977
02/18/11 09:36 PM
02/18/11 09:36 PM
Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
cheapstreetdustr Offline
master
cheapstreetdustr  Offline
master

Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
Eric..thanks for taking the time..
hopefully you wont have to have a thick skin to make it throught the tribulation of being new to this site..
Josh..go easy on him...you may have history with him before today..
but we dont want to baptise him by fire...so give him some breathing room..
as to your direct Question as to the hopping or porposeing..i am sure your gonna get a gammot of responses..
but guys when posting a question please put a little info on your perticular suspension . stock leaf-aftermarket leaf-ladder bar leaf-caltracs or 4 link, type set ups..as its hard to discern remidies for all suspensions..when each are effected differently.
Eric.
you mention'd some factors to these issues arent all shock related..some are suspension/spring related.
some are addressed at the front of the car.
some at the rear.
we will all hit the patience button when reflecting on this thread.


365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured
[image][/image]
Re: Shock Tech [Re: joshking440] #931978
02/18/11 09:37 PM
02/18/11 09:37 PM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



I have seen cars when they launch, the car spins and hooks and kicks left. Front end doesn't have a chance to come up.
I'm wondering if too heavy of a spring causes this.Ladder bar car with AFCO Double adjustables out back.

Re: Shock Tech [Re: cheapstreetdustr] #931979
02/18/11 09:44 PM
02/18/11 09:44 PM
Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
cheapstreetdustr Offline
master
cheapstreetdustr  Offline
master

Joined: Feb 2004
Posts: 6,257
acworth / N. georgia - south e...
Eric i dont know how intimate you are with Mopars specifically.
there are some factors that are different when diagnosing mopar type leaf sprung rear suspensions. the short front spring half is a factor. just to bring this to light not judge anyones knowledge..
i just want to put this out there..
If we are talking about mopar leaf sprung rear suspensions..
then proper rear shackle movement is a necessity to eleviate rear spring bind..in the extension of rear suspension travel..its a common problem for mopars...so is too short a shock itself..
these are both huge contributors to porpousing ..ie..hook unhook/unload..hook on a leafspring drag car..
as you can see i am passionate about this..
i am no expert...just someone who doesnt mind jumping in...ive helped fix this with a bunch of mopars...and some of it is ubiquitous in our world.
have at it..
cheapst..
and again Welcome...I am all ears..


365" Iron J heads,,3480lbs best 1.39 60ft on SS springs.10.54,124 mph ...6.67 1/8th et.average 60fts 1.46 w/ small cam &.063 no2 pill tagged & insured
[image][/image]
Re: Shock Tech [Re: cheapstreetdustr] #931980
02/18/11 10:08 PM
02/18/11 10:08 PM
Joined: Dec 2004
Posts: 10,549
Rittman Ohio
fourgearsavoy Offline
I Live Here
fourgearsavoy  Offline
I Live Here

Joined: Dec 2004
Posts: 10,549
Rittman Ohio
Well I have recently changed shocks from Pro-Comp truck shocks to the Rancho XL9000 series adjustable socks and have noticed a positive change.
My tires used to unload after the hit and wad up before they spun producing a very poor 1.7 60' time
Now since installing the Rancho shocks I have cut my 60' down to 1.41 on a marginal starting line.
The good shocks took the bounce out of the rear end and I am happy now and can see mid ten second ET's on the horizon
Gus


64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Shock Tech [Re: cheapstreetdustr] #931981
02/18/11 10:14 PM
02/18/11 10:14 PM
Joined: Nov 2009
Posts: 3,410
Belpre,Ohio
C
CHAPPER Offline
master
CHAPPER  Offline
master
C

Joined: Nov 2009
Posts: 3,410
Belpre,Ohio
I can see this is going to get confusing,,,it's like everybody is talking at once. Maybe,,try to answer one question at a time, and other posters have patience and just read and try to see if the questions posted are similar to their problems and learn from them...I hope Eric is ready for LOTS of PM's ...


If you like drag racing, support your local track.
Re: Shock Tech [Re: CHAPPER] #931982
02/18/11 10:39 PM
02/18/11 10:39 PM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



Quote:

I can see this is going to get confusing,,,it's like everybody is talking at once. Maybe,,try to answer one question at a time, and other posters have patience and just read and try to see if the questions posted are similar to their problems and learn from them...I hope Eric is ready for LOTS of PM's ...




Well his 1st post was at 5:49 pm and he hasn't been back since.

Re: Shock Tech #931983
02/18/11 11:10 PM
02/18/11 11:10 PM
Joined: May 2004
Posts: 2,864
IN
Irun5snd8th Offline
master
Irun5snd8th  Offline
master

Joined: May 2004
Posts: 2,864
IN
Quote:

Quote:

I can see this is going to get confusing,,,it's like everybody is talking at once. Maybe,,try to answer one question at a time, and other posters have patience and just read and try to see if the questions posted are similar to their problems and learn from them...I hope Eric is ready for LOTS of PM's ...




Well his 1st post was at 5:49 pm and he hasn't been back since.




Lets keep in mind that the guy has family and it is Friday night
Also, the thread is out here to get us some good shock technical information. The post about the basketball is the kind of thing we are looking for to get all of us thinking. That put it in terms we can all understand. We all have a car and he wont be able to tune every car on here. So lets give him a chance to give us some good information


AFCO, Rons Fuel Injection sponsored Dodge Challenger Mention Street Lethal Motorsports
Re: Shock Tech #931984
02/18/11 11:10 PM
02/18/11 11:10 PM
Joined: Mar 2007
Posts: 1,608
Rudolph, Ohio
moparguy7074 Offline
top fuel
moparguy7074  Offline
top fuel

Joined: Mar 2007
Posts: 1,608
Rudolph, Ohio
Quote:

Quote:

I can see this is going to get confusing,,,it's like everybody is talking at once. Maybe,,try to answer one question at a time, and other posters have patience and just read and try to see if the questions posted are similar to their problems and learn from them...I hope Eric is ready for LOTS of PM's ...




Well his 1st post was at 5:49 pm and he hasn't been back since.





If you saw the other thread on this, it wasnt supposed to start until Monday anyway.

Re: Shock Tech [Re: Irun5snd8th] #931985
02/18/11 11:22 PM
02/18/11 11:22 PM
Joined: Jan 2003
Posts: 19,304
Las Vegas
Al_Alguire Offline
I Live Here
Al_Alguire  Offline
I Live Here

Joined: Jan 2003
Posts: 19,304
Las Vegas
I agree give the guy a break. I would rather hear about theory and typical scenarios anbd prinicples than how many clicks Joe blows 12 second car needs on exte sion with his SS Springs. Just saying


"I am not ashamed to confess I am ignorant of what I do not know."

"It's never wrong to do the right thing"
Re: Shock Tech [Re: Al_Alguire] #931986
02/18/11 11:30 PM
02/18/11 11:30 PM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
Oh, just bustin his balls a little. Eric has been great to work with.... But don't tell me he doesn't deserve a typical moparts welcome

Re: Shock Tech [Re: Quicktree] #931987
02/19/11 12:15 AM
02/19/11 12:15 AM
Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
HEMIFRED Offline
master
HEMIFRED  Offline
master

Joined: Jul 2010
Posts: 3,502
SOUTH JERSEY
Quote:


I would like to know the difference in shocks, how they work, what makes one better than another, how effective the different types are etc




same here what is so different about the valving used by Santhuff as opposed to most other brands. What are the negatives of using them other than the outrageous costs.


home of the
Sox and Martin Hemi Duster


Re: Shock Tech [Re: joshking440] #931988
02/19/11 12:54 AM
02/19/11 12:54 AM
Joined: Feb 2007
Posts: 6,295
U.S.
M
moparniac Offline
master
moparniac  Offline
master
M

Joined: Feb 2007
Posts: 6,295
U.S.
Quote:

My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back




man c'mon! You have a 1300HP 9.0 car... i'd blame it on the shocks also


Mopar Performance
Re: Shock Tech [Re: HEMIFRED] #931989
02/19/11 01:08 AM
02/19/11 01:08 AM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:

Quote:


I would like to know the difference in shocks, how they work, what makes one better than another, how effective the different types are etc




same here what is so different about the valving used by Santhuff as opposed to most other brands. What are the negatives of using them other than the outrageous costs.






On those notes... What about how to look a shock dyno sheet a little and what to choose for your application. Like when to choose progressive, digressive, or linear shocks. Or what you want your Force vs. Velocity and Force vs. Displacement graphs to look like.

It's like, OK that what the graphs represent but what should I shoot for? How do you apply that info?

Maybe sort of like this but more specific to the application: http://www.circletrack.com/techarticles/shock_absorber_shock_dyno/index.html

Even a little like this very good read and info: http://www.nttyres.com/downloads/guide_to_dyno_graphs.pdf

Anyone want to build their own shock dyno?: http://www.circletrack.com/howto/82884_buildling_shock_dyno/index.html

Re: Shock Tech [Re: moparniac] #931990
02/19/11 01:17 AM
02/19/11 01:17 AM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
Quote:

Quote:

My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back




man c'mon! You have a 1300HP 9.0 car... i'd blame it on the shocks also




I can't wait.....

Re: Shock Tech #931991
02/19/11 01:33 AM
02/19/11 01:33 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Spring rate is very important...if the rear spring rate is too stiff, the car won't rotate properly. No shock will soften up enough. If the front end is dead, the car won't work as well as it can. If the bars have been in the car for a long time, they may need to be replaced. Both ends have to work together. Pinion angle is another variable that is in play. So, in your example as in most, there doesn't seem to be one answer...we have to plan the work and work the plan, one step at the time.

Re: Shock Tech [Re: CHAPPER] #931992
02/19/11 01:33 AM
02/19/11 01:33 AM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Quote:

I can see this is going to get confusing,,,it's like everybody is talking at once. Maybe,,try to answer one question at a time, and other posters have patience and just read and try to see if the questions posted are similar to their problems and learn from them...I hope Eric is ready for LOTS of PM's ...





No... no reason for that.... if Eric wants to answer
YOUR question all he needs to do is click on YOUR
post as a reply OR click on YOUR QUOTE and then
answer the question.... a LOT of guys just click
on the last post in line and in that case you wouldnt
know who your talking to.... by rights you would be
talking to the poster you clicked on.... so I WISH
the guys would catch on to post correctly
EDIT
I should say also that if he clicks on YOUR post as
REPLY it will have YOUR name on the top of the post
so look at the name on the post he is replying to
just to make sure you are reading the stuff that was
directed to YOU ...... hope that makes it clear to
ALL on the posting
Thanks..... also this has a sticky dont expect
the guy to JUMP when you ask a question... I'm sure
he has a JOB and a family.... its not going anywhere

Last edited by MR_P_BODY; 02/19/11 01:48 AM.
Re: Shock Tech [Re: joshking440] #931993
02/19/11 01:58 AM
02/19/11 01:58 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back




man c'mon! You have a 1300HP 9.0 car... i'd blame it on the shocks also




I can't wait.....




Could be the driver running out of talent?

Re: Shock Tech [Re: EricatAFCO] #931994
02/19/11 02:02 AM
02/19/11 02:02 AM
Joined: Jan 2003
Posts: 634
USA
S
Slider Offline
super gas
Slider  Offline
super gas
S

Joined: Jan 2003
Posts: 634
USA
Oooo, this could be good!!


�Hunt down those Chevies and Fords and crush �em like bugs!� ~ Tom Hoover

(O=o=====o=O)
Re: Shock Tech [Re: moderncylinder] #931995
02/19/11 02:09 AM
02/19/11 02:09 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

ive always been told you run compression tight and extension loose,,, when starting off would you run in the middle of your adjustments or bias it one way or the other? how about compression 1/4 way between, bias toward being hard,, and ext in the middle?? or???




Many factors determine where to start. The lower HP applications should begin on the soft end of the range. Keeping in mind that we need to control the rear tire, I usually work the rebound first. Start out soft and keep feeding more rebound into the car watching to see when performance begins to drop off. Compression can be used to control down track "wander" or again to prevent the basketball effect just off the line. I haven't been one to simply say to start in the middle...It may take a few runs to determine how much is too much.

Re: Shock Tech [Re: EricatAFCO] #931996
02/19/11 02:17 AM
02/19/11 02:17 AM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Quote:

Quote:

ive always been told you run compression tight and extension loose,,, when starting off would you run in the middle of your adjustments or bias it one way or the other? how about compression 1/4 way between, bias toward being hard,, and ext in the middle?? or???




Many factors determine where to start. The lower HP applications should begin on the soft end of the range. Keeping in mind that we need to control the rear tire, I usually work the rebound first. Start out soft and keep feeding more rebound into the car watching to see when performance begins to drop off. Compression can be used to control down track "wander" or again to prevent the basketball effect just off the line. I haven't been one to simply say to start in the middle...It may take a few runs to determine how much is too much.




Eric maybe you should clarify some of the terms
you will be using just for a base line so everyone
understands... I know I use terms like rebound and
compression but others use extension .... I also
use the term jounce and rebound but others dont seem
to use jounce(this is from when I worked in the
suspension lab at Chrysler
Thanks

Re: Shock Tech [Re: greendart408] #931997
02/19/11 02:17 AM
02/19/11 02:17 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...

Re: Shock Tech [Re: EricatAFCO] #931998
02/19/11 02:18 AM
02/19/11 02:18 AM
Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
WILD BILL Offline
Senior Member of the Junior Dragster Club
WILD BILL  Offline
Senior Member of the Junior Dragster Club

Joined: Dec 2007
Posts: 10,542
BROOK PARK, OH
Quote:

Quote:

Quote:

Quote:

My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back




man c'mon! You have a 1300HP 9.0 car... i'd blame it on the shocks also




I can't wait.....




Could be the driver running out of talent?





Just have to add to that one

Eric, I have a feeling your gonna fit right in here




I hope to learn a lot from this thread.



Re: Shock Tech [Re: cheapstreetdustr] #931999
02/19/11 02:19 AM
02/19/11 02:19 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Eric i dont know how intimate you are with Mopars specifically.
there are some factors that are different when diagnosing mopar type leaf sprung rear suspensions. the short front spring half is a factor. just to bring this to light not judge anyones knowledge..
i just want to put this out there..
If we are talking about mopar leaf sprung rear suspensions..
then proper rear shackle movement is a necessity to eleviate rear spring bind..in the extension of rear suspension travel..its a common problem for mopars...so is too short a shock itself..
these are both huge contributors to porpousing ..ie..hook unhook/unload..hook on a leafspring drag car..
as you can see i am passionate about this..
i am no expert...just someone who doesnt mind jumping in...ive helped fix this with a bunch of mopars...and some of it is ubiquitous in our world.
have at it..
cheapst..
and again Welcome...I am all ears..




Cheap,

Thanks for the input....we all will learn something

Re: Shock Tech [Re: fourgearsavoy] #932000
02/19/11 02:23 AM
02/19/11 02:23 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Well I have recently changed shocks from Pro-Comp truck shocks to the Rancho XL9000 series adjustable socks and have noticed a positive change.
My tires used to unload after the hit and wad up before they spun producing a very poor 1.7 60' time
Now since installing the Rancho shocks I have cut my 60' down to 1.41 on a marginal starting line.
The good shocks took the bounce out of the rear end and I am happy now and can see mid ten second ET's on the horizon
Gus




Four,

You are on the right track. The more gear, more torque and HP, the more control you will need from your shock. (If you go from a foot brake launch to trans brake, more shock control will be needed too) Also, if we don't step away from what we know and try something else, how do we know how much performance is still in there?

Re: Shock Tech [Re: EricatAFCO] #932001
02/19/11 02:31 AM
02/19/11 02:31 AM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Looking at a Road Race application on a 1968 Barracuda.…

Spring package:

350 lbs/in calculated at the ball joint wheel rate front springs (1.14” t-bars). 1.25” hollow sway bar

140 lbs/in rear leaf springs (sort of guessing at that +/-10 lbs). 3/4 “ sway bar that is adjustable

Computer wheel weight scale sheet as follows:

LF..987 RF..924
LR..731 RR..770

56% front weight bias

3412 lbs total weight

108 wheel base

**************************************************

Should I be looking at progressive, digressive, or linear shocks?

What kind of shock rates should I be looking at to control those springs in this application?

Do I need to get more info to make a better choice? If so what?

Last edited by autoxcuda; 02/19/11 02:57 AM.
Re: Shock Tech [Re: MR_P_BODY] #932002
02/19/11 02:31 AM
02/19/11 02:31 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

ive always been told you run compression tight and extension loose,,, when starting off would you run in the middle of your adjustments or bias it one way or the other? how about compression 1/4 way between, bias toward being hard,, and ext in the middle?? or???




Many factors determine where to start. The lower HP applications should begin on the soft end of the range. Keeping in mind that we need to control the rear tire, I usually work the rebound first. Start out soft and keep feeding more rebound into the car watching to see when performance begins to drop off. Compression can be used to control down track "wander" or again to prevent the basketball effect just off the line. I haven't been one to simply say to start in the middle...It may take a few runs to determine how much is too much.




Eric maybe you should clarify some of the terms
you will be using just for a base line so everyone
understands... I know I use terms like rebound and
compression but others use extension .... I also
use the term jounce and rebound but others dont seem
to use jounce(this is from when I worked in the
suspension lab at Chrysler
Thanks





Mr P, good point. Compression and jounce are the shock compressing-coming together. Rebound/extension is the shock pulling apart. I will try to use compresson and extension as the baseline...sometimes I find that the term, "rebound" slips out where I mean extension.

Re: Shock Tech [Re: EricatAFCO] #932003
02/19/11 02:35 AM
02/19/11 02:35 AM
Joined: Jun 2003
Posts: 9,225
Charleston
S
sixpackgut Offline
Drag Week Mod Champion
sixpackgut  Offline
Drag Week Mod Champion
S

Joined: Jun 2003
Posts: 9,225
Charleston
Quote:

Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...




can you explain how pinion angle has an effect on how a suspension acts?


Gen 3 power 6.22@110, 9.85@135
Follow @g3hemiswap on instagram

performance only racing, CRT, ultimate converter, superior design concepts, ThumperCarbs
Re: Shock Tech [Re: autoxcuda] #932004
02/19/11 02:55 AM
02/19/11 02:55 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Looking at a Road Race application on a 1968 Barracuda.…

Spring package:

350 lbs/in calculated at the ball joint wheel rate front springs (1.14” t-bars). 1.25” hollow sway bar

140 lbs/in rear leaf springs (sort of guessing at that). 3/4 “ sway bar that is adjustable

Computer wheel weight scale sheet as follows:

LF..987 RF..924
LR..731 RR..770

56% front weight bias

108 wheel base

**************************************************

Should I be looking at progressive, digressive, or linear shocks?

What kind of shock rates should I be looking at to control those springs in this application?

Do I need to get more info to make a better choice? If so what?




We have seen positive results in applying linear valving in autocross applications. The harder you charge the corners, the sticker the tires and the heavier the car, the more you will find the linear stuff to your liking...

As far as shock rates go, the variables are vast. Shock rates go up as shock speed increases. (On the shock dyno, if you run the shock at 6 inches per second, record the dampening rate, then spin that shock at 10 IPS, the shock will be stiffer given the same valving or setting). The shock rate does work to control the springs but also helps to control body roll...The higher the center of gravity, the harder you drive, tigher the corners etc, the stiffer the shocks need to be...

In your case, adjustable shocks would be a wise investment. One idea is to tune the shocks to your liking-performance is maximized and then getting the shocks dynoed. From there, you will have a baseline. Two things come from this exercise. One, you now have a file of each shock in case of damage and need for repair. Two, you can map where you are, see how much a click change makes in pounds of force (in the shock)and get an idea of how much the shock change will help you dial in the chassis. Gotta know how much to change something. Also, this could reduce the risk of tuning past the sweet spot when making a guess without hard data to support the tuning choice.

Re: Shock Tech [Re: EricatAFCO] #932005
02/19/11 03:14 AM
02/19/11 03:14 AM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:

Quote:

Looking at a Road Race application on a 1968 Barracuda.…

Spring package:

350 lbs/in calculated at the ball joint wheel rate front springs (1.14” t-bars). 1.25” hollow sway bar

140 lbs/in rear leaf springs (sort of guessing at that). 3/4 “ sway bar that is adjustable

Computer wheel weight scale sheet as follows:

LF..987 RF..924
LR..731 RR..770

56% front weight bias

108 wheel base

**************************************************

Should I be looking at progressive, digressive, or linear shocks?

What kind of shock rates should I be looking at to control those springs in this application?

Do I need to get more info to make a better choice? If so what?




We have seen positive results in applying linear valving in autocross applications. The harder you charge the corners, the sticker the tires and the heavier the car, the more you will find the linear stuff to your liking...

As far as shock rates go, the variables are vast. Shock rates go up as shock speed increases. (On the shock dyno, if you run the shock at 6 inches per second, record the dampening rate, then spin that shock at 10 IPS, the shock will be stiffer given the same valving or setting). The shock rate does work to control the springs but also helps to control body roll...The higher the center of gravity, the harder you drive, tigher the corners etc, the stiffer the shocks need to be...

In your case, adjustable shocks would be a wise investment. One idea is to tune the shocks to your liking-performance is maximized and then getting the shocks dynoed. From there, you will have a baseline. Two things come from this exercise. One, you now have a file of each shock in case of damage and need for repair. Two, you can map where you are, see how much a click change makes in pounds of force (in the shock)and get an idea of how much the shock change will help you dial in the chassis. Gotta know how much to change something. Also, this could reduce the risk of tuning past the sweet spot when making a guess without hard data to support the tuning choice.




Would you suggest linear valving also for this car in a Road Race application (Willow Springs) vs autocross?

What IPS rate do you guys use for your shocks? I've heard different companies use different rates, so it's tough to compare sometimes.

What kind of rate range at given IPS of adjustable shocks should I be looking for? Like what adjustable Afco shock would you recommend?

What about a non adjustable shock starting point? I may be able to adapt circle track shocks.

I can get shocks dyno'd. I help with a www.RacecarFactory.com (Jeff Schrader) big late model team out at Irwindale. The team has a dyno.

Last edited by autoxcuda; 02/19/11 02:23 PM.
Re: Shock Tech [Re: sixpackgut] #932006
02/19/11 09:23 AM
02/19/11 09:23 AM
Joined: Feb 2007
Posts: 6,295
U.S.
M
moparniac Offline
master
moparniac  Offline
master
M

Joined: Feb 2007
Posts: 6,295
U.S.
Quote:

Quote:

Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...




can you explain how pinion angle has an effect on how a suspension acts?




lolz here we go


Mopar Performance
Re: Shock Tech [Re: EricatAFCO] #932007
02/19/11 09:31 AM
02/19/11 09:31 AM
Joined: Feb 2007
Posts: 6,295
U.S.
M
moparniac Offline
master
moparniac  Offline
master
M

Joined: Feb 2007
Posts: 6,295
U.S.
Quote:

Quote:

Quote:

Quote:

My car separates real bad because my afco shocks can't take the horsepower...... Eric, weren't you gonna call me back




man c'mon! You have a 1300HP 9.0 car... i'd blame it on the shocks also




I can't wait.....




Could be the driver running out of talent?




I bought a pair of the AFCO DA's and have yet to try them out! I saw how much they made a difference on my buddies camaro with NO other changes... he used the intital setting used in the directions and went from 4-6" wheeelie to about a 12" wheelie carrying it out 10ft or so! I cant wait to try mine out either!



Mopar Performance
Re: Shock Tech [Re: EricatAFCO] #932008
02/19/11 10:18 AM
02/19/11 10:18 AM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



Quote:

Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...





It was my understanding that Ladder bars only need 2-3 degrees of nose down pinion angle.
What's the benefit of 5 degrees?

Re: Shock Tech [Re: HEMIFRED] #932009
02/19/11 12:04 PM
02/19/11 12:04 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:


I would like to know the difference in shocks, how they work, what makes one better than another, how effective the different types are etc




same here what is so different about the valving used by Santhuff as opposed to most other brands. What are the negatives of using them other than the outrageous costs.




A shock is defined as a hydraulic device that resists movement. Basic shocks have a piston on the end of the shaft with small ports machined in it. As the piston moves thru the column of oil, resistance is created. Only so much fluid can pass thru. The more force that is applied to the shock shaft, the more resistance is generated. Adjustable shocks are manufactured in many ways. Basic adjustable shocks utilize a ported plate that can be turned (by the adjustment mechanism) to cover (or uncover) the ports in the piston. If no restriction is selected, full flow occurs and the shock would be at the full soft setting for that shock. As you dial in more restriction, the shock gets stiffer. More advanced shocks use shims stacked on top of the piston. These shims vary in thickness, may have notches machined in them to allow flow and typically are stacked in a pyramid pattern. The theory here is that as force is applied to the shock, the oil acts on the shims causing them to "blow off". That is to say the shims go into a controlled flex. This action allows the shims to come away from the piston allowing more flow of oil. Now, add to this design a needle and seat mechanism. A needle and seat mechanism when used in a shock will control flow as well. The rule of thumb, like on a fuel pressure regulator is the deeper the needle is in the seat, the more flow is restricted>>>the more resistance is created.

So when you marry a shock design that has a properly ported piston, shim stacks that are built specifically to create the shape (on the dyno) that you are looking for and the needle and seat option, you can manufacture a shock that can control low, medium and high speed shock movements and make the transaction between all ranges very smoothly.

The real secret sauce is in how a shock company develops the valve curves and applys that technology to the type of racing one is working on..That is to say, if you can capture the data from a given application-you can measure how fast shocks move on a given car or typical suspension system, you can then manufacture a shock that adjusts within that proper operating range.

My example is that if you intend to work your engine in a range of 5000 to 7500 rpm, there is not much use in dynoing above that range.
Data acquistion systems are used to measure shock speeds to help shape the valving baselines of a shock program.

Some shocks are designed to be digressive in nature. Some linear and some progressive.
Digressive shocks blow off and do not get stiffer at the same rate as speed increases. (Picture two lines beginning in parallel lines. Speed is the top line, dampening is the bottom. As speed continues in a straight line, dampening begins to curve down.
Linear shock valving has both lines following each other all the way up.
Progressive shock valving is one where the dampening line goes up at a faster rate than the speed line...

One of the questions here specifically calls out a shock brand, what are the negatives of it other than cost etc.....It would not be proper for me to offer a comment here. I am not as familiar with that brand as they would be so my thought is it would be best to contact that company direct. Not ducking that question, just want to be fair.

Re: Shock Tech [Re: EricatAFCO] #932010
02/19/11 12:12 PM
02/19/11 12:12 PM
Joined: Jan 2003
Posts: 32,394
Q
Quicktree Offline
I Win
Quicktree  Offline
I Win
Q

Joined: Jan 2003
Posts: 32,394
Eric do you pics of different shocks and explain what each does with out naming brands? and maybe some diagrams of the flow each provide?

Re: Shock Tech #932011
02/19/11 12:31 PM
02/19/11 12:31 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...





It was my understanding that Ladder bars only need 2-3 degrees of nose down pinion angle.
What's the benefit of 5 degrees?




More pinion angle can be a benefit up to a point..as the pinion climbs the ring, it creates downforce. We want those vector forces going directly to the tire contact patch. Two things occur as the pinion gets parallel to the drive shaft, that downforce decreases and moves away from the tire contact patch. I have had the benefit of working with many chassis builders that tell me when they get a chance to work on a car that is not hooking consistently, and they find out the car is lacking some pinion angle, they immediately know that they can help that customer.

Remember, as in most cases, too much of a good thing can be a bad thing. Our u-joints cannot stand excessive angle. The weld yoke will crash into the pinion yoke or slip yoke. Also, as the pinion climbs the ring, the drive shaft moves into the transmission under acceleration....As you let off on the big end, the pinion drops. It then pulls the driveshaft out of the trans. The length of the slip yoke is crutial here..We need enough engagement to cover total movement..Contact your driveline company here for specs..

I would strongly encourage testing of all systems in your car (vary tire pressure, fuel pressure, shock settings, rear suspension changes, front suspension changes). We never know what we leave on the table unless we try something different.

I have personal experience in dialing in more pinion angle. I broke a rear end on a car that was working very well. (Spun the center center section on the tubes at 3 cars in a 5 grand race and killed her on the tree. However, my pass ended about 15 feet out). Replaced the housing but didn't have the same amount of pinion angle. The car didn't work the same. I sent my converter off. I replaced springs. I swapped slicks with no real success. Finally, I made it back to the rear end and added more angle. The car was instantly better-back to where it was previously.

Re: Shock Tech [Re: Quicktree] #932012
02/19/11 12:49 PM
02/19/11 12:49 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Eric do you pics of different shocks and explain what each does with out naming brands? and maybe some diagrams of the flow each provide?




I understand your end goal here is to gain some understanding of shocks....I believe that an answer to this question could conflict with one my personal beliefs which is to sell on the benefits of ones own product, not talk down the competition...Integrity is very important to me. I hope everyone understands. The shock company I work for uses billet pistions, shim stack design and needle & seat control to develop the curves that are targeted...This design allows for consistent performance, shock after shock. Each shock gets dynoed. Go-no tolerances are held close and the shock techs need to be able to confidently build a run of shocks as efficiently as possible. Also, this design lends itself very well to custom valving options/big power, small tire, drag radials etc.

Re: Shock Tech [Re: EricatAFCO] #932013
02/19/11 01:09 PM
02/19/11 01:09 PM
Joined: Jan 2003
Posts: 5,984
Anoka County, MN
L
Leigh Offline
master
Leigh  Offline
master
L

Joined: Jan 2003
Posts: 5,984
Anoka County, MN
Quote:

Quote:

Quote:

Quote:

I have been having this issue for awhile now. Car initially hooks then spins bad....I have had my double adj shocks all over with the adjustments and nothing seems to work at all. Have had 3 diff rear springs on it as well 150, 130, and now currently. 110s. Made no change. I run ladder bars. Im thinking I need a stiff sidewall tire. I run a 29.5x11.5 mt. Car runs mid to upper 1.3 s and 9.60s and weighs 3100. Should be in the high 1.2s. I feel with my alky injection. Any suggestions? Thanks for your time.




We want to spring the car as softly as possible without causing the spring to bow. The softer choice should provide the most consistent performance given multiple track conditions... If your car weights 3100 and is something like 55% front, 45% rear or so, The 110#'s should be ok, again as long as they aren't hitting the springs..

Ladder bar cars usually respond well to a fair amount of pinion angle. I have seen cars go from not trying to work with 2-3 degrees to hanging the front end with 5 degrees. Again, the front end has to work too. If it is dead, we may not get maximum performance out of the car. Also, we have to make sure we are bind free...





It was my understanding that Ladder bars only need 2-3 degrees of nose down pinion angle.
What's the benefit of 5 degrees?




More pinion angle can be a benefit up to a point..as the pinion climbs the ring, it creates downforce. We want those vector forces going directly to the tire contact patch. Two things occur as the pinion gets parallel to the drive shaft, that downforce decreases and moves away from the tire contact patch. I have had the benefit of working with many chassis builders that tell me when they get a chance to work on a car that is not hooking consistently, and they find out the car is lacking some pinion angle, they immediately know that they can help that customer.

Remember, as in most cases, too much of a good thing can be a bad thing. Our u-joints cannot stand excessive angle. The weld yoke will crash into the pinion yoke or slip yoke. Also, as the pinion climbs the ring, the drive shaft moves into the transmission under acceleration....As you let off on the big end, the pinion drops. It then pulls the driveshaft out of the trans. The length of the slip yoke is crutial here..We need enough engagement to cover total movement..Contact your driveline company here for specs..

I would strongly encourage testing of all systems in your car (vary tire pressure, fuel pressure, shock settings, rear suspension changes, front suspension changes). We never know what we leave on the table unless we try something different.

I have personal experience in dialing in more pinion angle. I broke a rear end on a car that was working very well. (Spun the center center section on the tubes at 3 cars in a 5 grand race and killed her on the tree. However, my pass ended about 15 feet out). Replaced the housing but didn't have the same amount of pinion angle. The car didn't work the same. I sent my converter off. I replaced springs. I swapped slicks with no real success. Finally, I made it back to the rear end and added more angle. The car was instantly better-back to where it was previously.




Eric. Sounds like my car to a T. Regarding pinion angle, I read that same idea in 1998. It was dismissed by some, but I always thought it made sense. Looks like it's time to try something other than 2*. Thanks for the tips.
Leigh

Re: Shock Tech [Re: Leigh] #932014
02/20/11 12:20 PM
02/20/11 12:20 PM
Joined: Jan 2003
Posts: 9,963
Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
master
gregsdart  Offline
master

Joined: Jan 2003
Posts: 9,963
Frostbitefalls MN (Rocky&Bullw...
When you suggest more pinion angle, are you adjusting the angle itself by adjusting the ladderbar only (no movement of the front mount or vehicle height change) and leaving the instant center in the exact same location?

Last edited by gregsdart; 02/20/11 12:26 PM.

8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: Shock Tech [Re: gregsdart] #932015
02/20/11 12:25 PM
02/20/11 12:25 PM
Joined: Jan 2003
Posts: 9,963
Frostbitefalls MN (Rocky&Bullw...
gregsdart Offline
master
gregsdart  Offline
master

Joined: Jan 2003
Posts: 9,963
Frostbitefalls MN (Rocky&Bullw...

I have Afco double adjustables on all four corners. Great shocks, looking to get the most out of them. I have the car in the sig obviously, 3000 lbs, ladder bars 30 inches long, leave off trans brake at 4500 Vs a 6400 stall. The weight dist is now 47.5 rear 52.5 front. I have started testing with the rears soft on extension, medium on compression and have progressed to about the middle of their adjustment for stiffness, seems to be about right as the 60 fts went from 1.28 down to 1.259 and got very consistent. Fronts are still dead soft on extension , fairly stiff on compression to help with the landing.
Where would you go from here? The car wheelstands and hits the 66 inch wheelie bars fairly hard. I have about four inches of travel up front.
My thoughts are to start stiffening the shock rebound a touch, then after finding a good point for that start shortening front travel, which is about four inch of rise. Any change to that plan?


8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
Re: Shock Tech [Re: gregsdart] #932016
02/20/11 02:51 PM
02/20/11 02:51 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

When you suggest more pinion angle, are you adjusting the angle itself by adjusting the ladderbar only (no movement of the front mount or vehicle height change) and leaving the instant center in the exact same location?




Yes, dial in more pinion angle and leave the front heim joint in the same position..When adjusting pinion angle, take care to adjust both sides equally. It is easy to make an adjustment to pinion angle and change how the car leaves right to left too. If the left tire has too much influence, the car goes right. Same for the right tire...So, if the car is making a move off the line, make an adjustment to the opposite side. Your goal is to make that corner heavier. More static weight=more inherent traction. .Also,a change in ride height will change the IC height.Your are correct in your assumption to leave vehicle height the same too.

As we begin to realize what changes affect the car, we can then apply them when a different problem presents....(travel to another track) That is why I encourage tuning the suspenion as much as we tend to tune the engine..I remember starting out and feeling comfortable with changing jets, timing, lash.
However, changing pinion angle, shock settings, preload was strictly not discussed...like the car was going to make a big ole turn into the wall. Unless something fails, the car should not make a dramatic enough move to cause something real bad. Test N Tune work on the front side should pay dividends (consistency, understanding cause and effect) on the backside.

Re: Shock Tech [Re: gregsdart] #932017
02/20/11 02:59 PM
02/20/11 02:59 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:


I have Afco double adjustables on all four corners. Great shocks, looking to get the most out of them. I have the car in the sig obviously, 3000 lbs, ladder bars 30 inches long, leave off trans brake at 4500 Vs a 6400 stall. The weight dist is now 47.5 rear 52.5 front. I have started testing with the rears soft on extension, medium on compression and have progressed to about the middle of their adjustment for stiffness, seems to be about right as the 60 fts went from 1.28 down to 1.259 and got very consistent. Fronts are still dead soft on extension , fairly stiff on compression to help with the landing.
Where would you go from here? The car wheelstands and hits the 66 inch wheelie bars fairly hard. I have about four inches of travel up front.
My thoughts are to start stiffening the shock rebound a touch, then after finding a good point for that start shortening front travel, which is about four inch of rise. Any change to that plan?




I think you are headed in the right direction...I tend to like to initially control front end travel with the shock...It is a more passive way to limit travel when compared to a chain, cable stop or bolt in the upper arm. In your case, tighten the front shocks on rebound until the car slips the tire. The 60' numbers could improve but I am betting that if we continue to hook the HP you have without hitting the bars as hard, we will improve the overall package. Each time we hit the bars, load is relieved from the tire contact patch. Sometimes greater than others...Extreme cases will induce slip.

Also, the rebound on the rear shocks can change how hard you hit the bars too. Stiffening them will slow down separation (which is what we need to manufacture enough traction) Double edge sword. Work with the front shocks first. Find the maximum setting the car will stand and then go back to the rears and make some adjustments. Worse case is it spins, you re-adjust the shocks (back)and go kick some ass!

Re: Shock Tech [Re: EricatAFCO] #932018
02/20/11 03:46 PM
02/20/11 03:46 PM
Joined: Sep 2010
Posts: 52
USA eastern PA
340Bird Offline
member
340Bird  Offline
member

Joined: Sep 2010
Posts: 52
USA eastern PA
I,m looking at shocks for my car. I'm in the prosess of installing ladder bars. Would a 7" travel shock on the rear be better than a 5" travel? I am looking at Afco #3875 or #3855 single adjustable.
The car is a four speed,for now, about 3000#.
SK

Re: Shock Tech [Re: autoxcuda] #932019
02/20/11 04:16 PM
02/20/11 04:16 PM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
You said linear shock for autocross. Would you also suggest linear valving also for this car in a Road Race application (Willow Springs)?

What kind of rate range at given IPS of adjustable shocks should I be looking for? Like between the 16, 13, 38, and 32 series which fits the range you suggest? Which ones are linear, digressive, progressive?

What about a non adjustable shock starting point?

Re: Shock Tech [Re: Al_Alguire] #932020
02/20/11 04:36 PM
02/20/11 04:36 PM
Joined: Dec 2004
Posts: 10,549
Rittman Ohio
fourgearsavoy Offline
I Live Here
fourgearsavoy  Offline
I Live Here

Joined: Dec 2004
Posts: 10,549
Rittman Ohio
Quote:

I agree give the guy a break. I would rather hear about theory and typical scenarios anbd prinicples than how many clicks Joe blows 12 second car needs on exte sion with his SS Springs. Just saying





64 Plymouth Savoy
493 Indy EZ's by Nick at Compu-Flow
5-Speed Richmond faceplate Liberty box
Dana 60
Re: Shock Tech [Re: fourgearsavoy] #932021
02/21/11 10:31 AM
02/21/11 10:31 AM
Joined: Jan 2003
Posts: 10,009
MN
J
JERICOGTX Offline
I Live Here
JERICOGTX  Offline
I Live Here
J

Joined: Jan 2003
Posts: 10,009
MN
I'm still waiting for my catalog I signed up for on Afco's website... That was at least 3 months ago.

Jeff


69 GTX 68 Road Runner
Re: Shock Tech [Re: JERICOGTX] #932022
02/21/11 11:21 AM
02/21/11 11:21 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

I'm still waiting for my catalog I signed up for on Afco's website... That was at least 3 months ago.

Jeff




Jeff,

Sorry for the delay. Please send your mailing address to my work email address-we will be sure to get one going ASAP.

eesaffell@afcoracing.com

Re: Shock Tech [Re: 340Bird] #932023
02/21/11 11:33 AM
02/21/11 11:33 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

I,m looking at shocks for my car. I'm in the prosess of installing ladder bars. Would a 7" travel shock on the rear be better than a 5" travel? I am looking at Afco #3875 or #3855 single adjustable.
The car is a four speed,for now, about 3000#.
SK




When thinking about shock selection with regards to stroke, remember that most cars will only use about 3-4" of travel total, up and down combined.Many will use less..Some cars carry the long shock to allow the housing to drop out further making swapping tires easier..

Most back half cars use a 5" stroke shock. Consider if you plan to mount the upper cross shock mount BELOW the trunk pan, and use adjustable lower shock brackets, you will be able to set the shock in the middle of it's stroke, set ride height and be fine....If your plans are to mount the upper shock mount ABOVE the trunk pan in some trick config, a longer shock can be used.

On a shock dyno, if the valving package within the shock is the same, shocks of varying lengths will perform the same. It just comes down to packaging for the vehicle.

Re: Shock Tech [Re: autoxcuda] #932024
02/21/11 12:14 PM
02/21/11 12:14 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

You said linear shock for autocross. Would you also suggest linear valving also for this car in a Road Race application (Willow Springs)?

What kind of rate range at given IPS of adjustable shocks should I be looking for? Like between the 16, 13, 38, and 32 series which fits the range you suggest? Which ones are linear, digressive, progressive?

What about a non adjustable shock starting point?





Autox,

Tracks like Willow Springs or any faster road course will like the linear valving as well. The heavier the car, the more we can work with shocks to help performance....(Sporty cars are already built for handling, shocks are important to them but really important to guys running American Muscle on road courses)

Regarding valve ranges....we have seen a need to have shocks dampen at rates of 600#'s@6 IPS..That is over 1000# at 10-13 IPS. so I think you could look for a shock to be in this area as a good starting point to begin..Again, how serious your effort is and how aggressive you drive will help shape the shock. The good thing is shocks can be valved to do many different things when you have the shim stack/needle & seat design.

On the question of non-adjustable shocks, a shock package can be built that will give good service. However, you are fixed with that valving. In the case of one shock company I know rather well, one can purchase single adjustable shocks at a similar price and get more bang for the buck..

Re: Shock Tech [Re: EricatAFCO] #932025
02/21/11 12:17 PM
02/21/11 12:17 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Eric... on a single adjustable shock is the control
valve controlling JUST the extension or does it also
control the compression.... I have a old set of QA-1s
and was told it is only controlling the extension
but they are old.... now I hear a lot of shocks are
controlling both on a single adjustable shock

Re: Shock Tech [Re: MR_P_BODY] #932026
02/21/11 12:45 PM
02/21/11 12:45 PM
Joined: Nov 2004
Posts: 6,890
North Alabama
M
Monte_Smith Offline
master
Monte_Smith  Offline
master
M

Joined: Nov 2004
Posts: 6,890
North Alabama
I have seen Eric mention it a couple times here, but I don't think emphatically enough...........guys the front of the car, HAS TO WORK, before you can do anything with the rear. The front shocks and suspension, are likely just as important, maybe more so, than the rear. I see guys all the time with nice shocks on the rear and junk 3-ways on the front. When the car still won't work, they surmise the good shocks were a waste of money. Got to make the front work.

And while we are talking about front shocks, let me just say that every car out there, does NOT need 7" of travel and loosey goosey shocks in the front. In these days of power, good tires, good tracks and good suspension, a ton of pitch rotation, like was needed in the past, is just not a requirement these days. Most will work with a relatively stiff front setup.

Hey Eric, I know the guys at TRZ had mentioned to you a project I had going on a Holley. Did you ever get a chance to look into that

Thanks

Monte

Re: Shock Tech [Re: EricatAFCO] #932027
02/21/11 01:04 PM
02/21/11 01:04 PM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:

Quote:

You said linear shock for autocross. Would you also suggest linear valving also for this car in a Road Race application (Willow Springs)?

What kind of rate range at given IPS of adjustable shocks should I be looking for? Like between the 16, 13, 38, and 32 series which fits the range you suggest? Which ones are linear, digressive, progressive?

What about a non adjustable shock starting point?





Autox,

Tracks like Willow Springs or any faster road course will like the linear valving as well. The heavier the car, the more we can work with shocks to help performance....(Sporty cars are already built for handling, shocks are important to them but really important to guys running American Muscle on road courses)

Regarding valve ranges....we have seen a need to have shocks dampen at rates of 600#'s@6 IPS..That is over 1000# at 10-13 IPS. so I think you could look for a shock to be in this area as a good starting point to begin..Again, how serious your effort is and how aggressive you drive will help shape the shock. The good thing is shocks can be valved to do many different things when you have the shim stack/needle & seat design.

On the question of non-adjustable shocks, a shock package can be built that will give good service. However, you are fixed with that valving. In the case of one shock company I know rather well, one can purchase single adjustable shocks at a similar price and get more bang for the buck..




Thank you very much. That gives me some parameters to start with.

Now I look on the Afco website, how do I tell what rate and what liner curves each 16, 13, 38, and 32 series Afco shock has for my car? Or are they custom built to order?


I got these shocks below for song at a Swap Meet that were supposed to be front shocks set up for Road Racing. They are too tall for my car anyway.

I had them dynod by the guys but I'm like, "Now what?" Just a bunch of numbers that I don't know if they apply to my situation. But they don't seem to have enough rate from what you are saying? Or are these rear shocks. Should the rears be 600#'s @ 6 IPS

Tests at 6 IPS and shock 100 degrees warmup..




6487823-CO_CCgraph.jpg (362 downloads)
Last edited by autoxcuda; 02/21/11 01:25 PM.
Re: Shock Tech [Re: autoxcuda] #932028
02/21/11 01:40 PM
02/21/11 01:40 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

You said linear shock for autocross. Would you also suggest linear valving also for this car in a Road Race application (Willow Springs)?

What kind of rate range at given IPS of adjustable shocks should I be looking for? Like between the 16, 13, 38, and 32 series which fits the range you suggest? Which ones are linear, digressive, progressive?

What about a non adjustable shock starting point?





Autox,

Tracks like Willow Springs or any faster road course will like the linear valving as well. The heavier the car, the more we can work with shocks to help performance....(Sporty cars are already built for handling, shocks are important to them but really important to guys running American Muscle on road courses)

Regarding valve ranges....we have seen a need to have shocks dampen at rates of 600#'s@6 IPS..That is over 1000# at 10-13 IPS. so I think you could look for a shock to be in this area as a good starting point to begin..Again, how serious your effort is and how aggressive you drive will help shape the shock. The good thing is shocks can be valved to do many different things when you have the shim stack/needle & seat design.

On the question of non-adjustable shocks, a shock package can be built that will give good service. However, you are fixed with that valving. In the case of one shock company I know rather well, one can purchase single adjustable shocks at a similar price and get more bang for the buck..




Thank you very much. That gives me some parameters to start with.

Now I look on the Afco website, how do I tell what rate and what liner curves each 16, 13, 38, and 32 series Afco shock has for my car?

I got these shock I had dyno'd below for song at a Swap Meet that were supposed to be front shocks set up for Road Racing. They are too tall for my car anyway, but the don't seem to have enough rate? Or are these rear shocks. Should the rears be 600#'s @ 6 IPS

Tests at 6 IPS and shock 100 degrees warmup..








The 16 and 13 series shocks are expressed in valve numbers.(They are fixed valve shocks)..An example is 1675 or 1375T. The last digit in this case represents the dampening. "5" is typically the mid-point in dampening from soft to stiff. The 32 series shocks are gas charged monotube shocks and are a good shock for hard road racing applications. They are designed for heavy usage and for road racing, will resist fading very well. Any valve code config can be developed in this series of shock. They are adjustable, single or double. The 38 series shocks are initially destined for drag racing...However, we can shape the graph to what is needed. Normally, the series of shocks you list are built with a digressive code for shelf stock...(There are some exceptions though-mostly circle track applications)

..Looking at your dyno graphs, those shocks will be significantly stiffer than OE. Also, they will provide an improvment in performance...I don't think we can determine which end these shocks were built for...Probably built to an application-what someone had some success with for the car they were working on...If you were replacing stock type shocks, these will be a ton better.

Have you ran them? If so, what results did you see?

Re: Shock Tech [Re: EricatAFCO] #932029
02/21/11 01:49 PM
02/21/11 01:49 PM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:


The 16 and 13 series shocks are expressed in valve numbers.(They are fixed valve shocks)..An example is 1675 or 1375T. The last digit in this case represents the dampening. "5" is typically the mid-point in dampening from soft to stiff. The 32 series shocks are gas charged monotube shocks and are a good shock for hard road racing applications. They are designed for heavy usage and for road racing, will resist fading very well. Any valve code config can be developed in this series of shock. They are adjustable, single or double. The 38 series shocks are initially destined for drag racing...However, we can shape the graph to what is needed. Normally, the series of shocks you list are built with a digressive code for shelf stock...(There are some exceptions though-mostly circle track applications)

..Looking at your dyno graphs, those shocks will be significantly stiffer than OE. Also, they will provide an improvment in performance...I don't think we can determine which end these shocks were built for...Probably built to an application-what someone had some success with for the car they were working on...If you were replacing stock type shocks, these will be a ton better.

Have you ran them? If so, what results did you see?




No, I haven't ran them. The lengths are not right for the front. But probably ok for the rear in terms of physical fit.

When you mentioned 600#s before, is that rebound?

What #'s at 6 IPS would a rear shock starting point be?

With the 32 and 38 series, is there an extra cost associated with custom valving; to make them linear and in the 600# range of adjustability?

Last edited by autoxcuda; 02/21/11 01:53 PM.
Re: Shock Tech [Re: EricatAFCO] #932030
02/21/11 02:13 PM
02/21/11 02:13 PM
Joined: Oct 2003
Posts: 11,678
W. Kentucky
justinp61 Offline
I Live Here
justinp61  Offline
I Live Here

Joined: Oct 2003
Posts: 11,678
W. Kentucky
Eric

Thanks for coming here and helping out . Shocks seem to be one of those subjects that almost everyone has an opinion on but in reality only a few actually know much about.

I've asked this question in a PM to one of the "experts" here and all I got a smart a$$ pm reply. So I'll try again.

My car is a 3260# 69 Dart, 54%F/46%R weight distribution, street/strip, pump gas 408 that runs high 6.50s in the 1/8, foot brake, 727 with a loose 9.5" converter, Dana with 4.10 gears, 325/50 MT ET Street Radials. Consistently goes 1.38-1.39 60'on a decent track. It will pick the front tires up about 10" and carry them out about 10' before sitting them down. On a bad track I have problems hooking, it will spin at the hit.

It has Cal Tracs with Rancho 9 ways on the rear and CE 3 ways on the front, set at 90/10. The front has 5.5" of travel.

Can I expect a significant gain by going to double adjustables on all four corners? How much will they help on a bad track? What adjustments would need to be made to for a bad track?

Re: Shock Tech [Re: justinp61] #932031
02/21/11 02:32 PM
02/21/11 02:32 PM
Joined: Nov 2004
Posts: 6,890
North Alabama
M
Monte_Smith Offline
master
Monte_Smith  Offline
master
M

Joined: Nov 2004
Posts: 6,890
North Alabama
Quote:

Eric

Thanks for coming here and helping out . Shocks seem to be one of those subjects that almost everyone has an opinion on but in reality only a few actually know much about.

I've asked this question in a PM to one of the "experts" here and all I got a smart a$$ pm reply. So I'll try again.

My car is a 3260# 69 Dart, 54%F/46%R weight distribution, street/strip, pump gas 408 that runs high 6.50s in the 1/8, foot brake, 727 with a loose 9.5" converter, Dana with 4.10 gears, 325/50 MT ET Street Radials. Consistently goes 1.38-1.39 60'on a decent track. It will pick the front tires up about 10" and carry them out about 10' before sitting them down. On a bad track I have problems hooking, it will spin at the hit.

It has Cal Tracs with Rancho 9 ways on the rear and CE 3 ways on the front, set at 90/10. The front has 5.5" of travel.

Can I expect a significant gain by going to double adjustables on all four corners? How much will they help on a bad track? What adjustments would need to be made to for a bad track?


Justin, I'm not Eric, but I do have a lot of experience with radial tired cars. Your car obviously works well, but radials are extremely surface sensitive, if you have power. They just won't work on a bad track. The problem is, you can't just "smack" a radial, like you can a slick, so on a bad track, all the things you do with slicks to hit them harder, don't help the radial. About the only recourse is calm the car down. Sure 60fts suffer, but that is what it takes to get a radial down a crappy track.

As far as the good shocks. I think they help tremendously and will make the car much more "repeatable", but while they may help, they won't fix a truly bad track, not for radials anyway.

I tune on a lot of radial cars, some tracks we go teens in 60ft, some tracks we can only go .30s in 60ft and I have had to back off to .40s at certain tracks.

Monte

Monte

Re: Shock Tech [Re: Monte_Smith] #932032
02/21/11 02:45 PM
02/21/11 02:45 PM
Joined: Oct 2003
Posts: 11,678
W. Kentucky
justinp61 Offline
I Live Here
justinp61  Offline
I Live Here

Joined: Oct 2003
Posts: 11,678
W. Kentucky
Thanks Monty

My converter is very loose, it flashes 6000. Will raising the launch rpm help? It seems this would be less of a hit on the tires. I have the 325s on a 10" wheel, will a 12" wheel be better?

I don't have a problem buying new shocks, just want to make sure I'm not throwing $$$$$$ at it and hoping it will help.

Re: Shock Tech [Re: autoxcuda] #932033
02/21/11 03:14 PM
02/21/11 03:14 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:


The 16 and 13 series shocks are expressed in valve numbers.(They are fixed valve shocks)..An example is 1675 or 1375T. The last digit in this case represents the dampening. "5" is typically the mid-point in dampening from soft to stiff. The 32 series shocks are gas charged monotube shocks and are a good shock for hard road racing applications. They are designed for heavy usage and for road racing, will resist fading very well. Any valve code config can be developed in this series of shock. They are adjustable, single or double. The 38 series shocks are initially destined for drag racing...However, we can shape the graph to what is needed. Normally, the series of shocks you list are built with a digressive code for shelf stock...(There are some exceptions though-mostly circle track applications)

..Looking at your dyno graphs, those shocks will be significantly stiffer than OE. Also, they will provide an improvment in performance...I don't think we can determine which end these shocks were built for...Probably built to an application-what someone had some success with for the car they were working on...If you were replacing stock type shocks, these will be a ton better.

Have you ran them? If so, what results did you see?




No, I haven't ran them. The lengths are not right for the front. But probably ok for the rear in terms of physical fit.

When you mentioned 600#s before, is that rebound?

What #'s at 6 IPS would a rear shock starting point be?

With the 32 and 38 series, is there an extra cost associated with custom valving; to make them linear and in the 600# range of adjustability?




Yes, good catch (sorry about this), 600# on the rebound side of the shock.....

Rear shock settings could start at 300#. Again depends on how brave you are??? If you plan to get the most out of it, you may want more control.

Regarding revalve expense, if we have a code established already,(we have many), the charge is modest at $55.00/shock. (Linear would be in this range)...The piston is a different configuration with it's appropriate shim stack.

Re: Shock Tech [Re: EricatAFCO] #932034
02/21/11 03:30 PM
02/21/11 03:30 PM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:

Quote:

Quote:


The 16 and 13 series shocks are expressed in valve numbers.(They are fixed valve shocks)..An example is 1675 or 1375T. The last digit in this case represents the dampening. "5" is typically the mid-point in dampening from soft to stiff. The 32 series shocks are gas charged monotube shocks and are a good shock for hard road racing applications. They are designed for heavy usage and for road racing, will resist fading very well. Any valve code config can be developed in this series of shock. They are adjustable, single or double. The 38 series shocks are initially destined for drag racing...However, we can shape the graph to what is needed. Normally, the series of shocks you list are built with a digressive code for shelf stock...(There are some exceptions though-mostly circle track applications)

..Looking at your dyno graphs, those shocks will be significantly stiffer than OE. Also, they will provide an improvment in performance...I don't think we can determine which end these shocks were built for...Probably built to an application-what someone had some success with for the car they were working on...If you were replacing stock type shocks, these will be a ton better.

Have you ran them? If so, what results did you see?




No, I haven't ran them. The lengths are not right for the front. But probably ok for the rear in terms of physical fit.

When you mentioned 600#s before, is that rebound?

What #'s at 6 IPS would a rear shock starting point be?

With the 32 and 38 series, is there an extra cost associated with custom valving; to make them linear and in the 600# range of adjustability?




Yes, good catch (sorry about this), 600# on the rebound side of the shock.....

Rear shock settings could start at 300#. Again depends on how brave you are??? If you plan to get the most out of it, you may want more control.

Regarding revalve expense, if we have a code established already,(we have many), the charge is modest at $55.00/shock. (Linear would be in this range)...The piston is a different configuration with it's appropriate shim stack.




What #lbs shock would you suggest for a rear shock starting point to go with a 600# front?

Is their a percentage of split general rule of thumb for front to rear shock # for road race applications? Is driving experiance a factor?

I'm no pro driver, I'm on the learning curve.

Does the afco website show the off the shelf adjustment ranges and valving types for the 32 and 38 series pro touring shocks? Or in your catalog?

Last edited by autoxcuda; 02/21/11 03:40 PM.
Re: Shock Tech [Re: Monte_Smith] #932035
02/21/11 04:41 PM
02/21/11 04:41 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Eric

Thanks for coming here and helping out . Shocks seem to be one of those subjects that almost everyone has an opinion on but in reality only a few actually know much about.

I've asked this question in a PM to one of the "experts" here and all I got a smart a$$ pm reply. So I'll try again.

My car is a 3260# 69 Dart, 54%F/46%R weight distribution, street/strip, pump gas 408 that runs high 6.50s in the 1/8, foot brake, 727 with a loose 9.5" converter, Dana with 4.10 gears, 325/50 MT ET Street Radials. Consistently goes 1.38-1.39 60'on a decent track. It will pick the front tires up about 10" and carry them out about 10' before sitting them down. On a bad track I have problems hooking, it will spin at the hit.

It has Cal Tracs with Rancho 9 ways on the rear and CE 3 ways on the front, set at 90/10. The front has 5.5" of travel.

Can I expect a significant gain by going to double adjustables on all four corners? How much will they help on a bad track? What adjustments would need to be made to for a bad track?


Justin, I'm not Eric, but I do have a lot of experience with radial tired cars. Your car obviously works well, but radials are extremely surface sensitive, if you have power. They just won't work on a bad track. The problem is, you can't just "smack" a radial, like you can a slick, so on a bad track, all the things you do with slicks to hit them harder, don't help the radial. About the only recourse is calm the car down. Sure 60fts suffer, but that is what it takes to get a radial down a crappy track.

As far as the good shocks. I think they help tremendously and will make the car much more "repeatable", but while they may help, they won't fix a truly bad track, not for radials anyway.

I tune on a lot of radial cars, some tracks we go teens in 60ft, some tracks we can only go .30s in 60ft and I have had to back off to .40s at certain tracks.

Monte

Monte




Great stuff Monte....Regardless if the car is a Power adder car or a NA car, we have to realize that we have to do what we have to do to gain consistency. If that means softening up the leave, we gotta do it. I would suggest trying some passes where you soften up the bottom end some and see how the car responds.

Re: Shock Tech [Re: Monte_Smith] #932036
02/21/11 04:55 PM
02/21/11 04:55 PM
Joined: Feb 2007
Posts: 6,295
U.S.
M
moparniac Offline
master
moparniac  Offline
master
M

Joined: Feb 2007
Posts: 6,295
U.S.
Quote:

And while we are talking about front shocks, let me just say that every car out there, does NOT need 7" of travel and loosey goosey shocks in the front. In these days of power, good tires, good tracks and good suspension, a ton of pitch rotation, like was needed in the past, is just not a requirement these days. Most will work with a relatively stiff front setup.





I always kinda wondered how the guys with caltracs in the back could get to work with the front coil over setup to hook so good when calvert says 5" minimum travel up front....


Mopar Performance
Re: Shock Tech [Re: moparniac] #932037
02/21/11 09:29 PM
02/21/11 09:29 PM
Joined: Jun 2008
Posts: 577
Arkansas
A
Adrielp Offline
mopar
Adrielp  Offline
mopar
A

Joined: Jun 2008
Posts: 577
Arkansas
Eric my question is in regards to knowing when to try lower rate springs. We have a 3150lb bracket car that makes about 550HP. It has a ladder bar rears suspension with single adjustable coil over shocks and we are currently using a 150rate spring as that is what the chart suggested based on rear end weight. The car leaves pretty good and has averaged low 1.40 60fts. I believe it should be about 5 hundredths or so faster on average but its something that we are trying to get better with while not moving too fast. I've wondered though if our car would benefit from a softer spring in the rear. I've personally called two well known chassis builders and have received two very different thoughts on what spring to use. One said to stay with the 150 and they other said to use a 95 rate spring. I've seen both of there cars run and they both leave good and are fast(one def leaves better though). So with all that said, What are your thoughts on the matter?


Adriel Paradise
Substation Design Engineer III
Re: Shock Tech [Re: Adrielp] #932038
02/21/11 11:02 PM
02/21/11 11:02 PM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
We must of scared him off......I called him 65 times today, sent him 103 emails....no response.

Re: Shock Tech [Re: joshking440] #932039
02/22/11 12:46 AM
02/22/11 12:46 AM
Joined: Jan 2003
Posts: 27,444
So Cal
autoxcuda Offline
Too Many Posts
autoxcuda  Offline
Too Many Posts

Joined: Jan 2003
Posts: 27,444
So Cal
Quote:

We must of scared him off......I called him 65 times today, sent him 103 emails....no response.




It's a holiday. And if he's at work, he probably has other stuff going on too.

Re: Shock Tech [Re: joshking440] #932040
02/22/11 10:14 AM
02/22/11 10:14 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

We must of scared him off......I called him 65 times today, sent him 103 emails....no response.




Hey Dude, when we talked yesterday, I asked you to contribute something positive....After 63 calls from you and 102 emails yesterday, I was positively NOT going to answer!!!! LOL.

Re: Shock Tech [Re: EricatAFCO] #932041
02/22/11 11:13 AM
02/22/11 11:13 AM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
Quote:

Quote:

We must of scared him off......I called him 65 times today, sent him 103 emails....no response.




Hey Dude, when we talked yesterday, I asked you to contribute something positive....After 63 calls from you and 102 emails yesterday, I was positively NOT going to answer!!!! LOL.




hahaha, yea I know, but you have to give me an a for annoying you...

Re: Shock Tech [Re: joshking440] #932042
02/22/11 11:15 AM
02/22/11 11:15 AM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
Actually gents, I have know Eric and the guys at Afco for some time now.

Eric is a good guy and has helped me in every way he can. He is also going to be re-valving my shocks for me to help slow down the violent seperation that is happening in the car.

Once Eric gets his feet wet here, and everyone gets to know him and his product, Im sure we will see more "blue" shocks at the track....

Im actually suprised wild bill doesnt have a set already, just based on the fact that they are blue!

Last edited by joshking440; 02/22/11 11:21 AM.
Re: Shock Tech [Re: Adrielp] #932043
02/22/11 11:20 AM
02/22/11 11:20 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Eric my question is in regards to knowing when to try lower rate springs. We have a 3150lb bracket car that makes about 550HP. It has a ladder bar rears suspension with single adjustable coil over shocks and we are currently using a 150rate spring as that is what the chart suggested based on rear end weight. The car leaves pretty good and has averaged low 1.40 60fts. I believe it should be about 5 hundredths or so faster on average but its something that we are trying to get better with while not moving too fast. I've wondered though if our car would benefit from a softer spring in the rear. I've personally called two well known chassis builders and have received two very different thoughts on what spring to use. One said to stay with the 150 and they other said to use a 95 rate spring. I've seen both of there cars run and they both leave good and are fast(one def leaves better though). So with all that said, What are your thoughts on the matter?




My feelings are that springs should be mainly tasked to hold up the chassis without major bowing when loaded....Seemingly, the softest spring we can use (without bowing) on a car will produce the most consistent performance over varying starting line and down track conditions. Also, an over sprung car will not respond to shock changes as much as a properly sprung car.

If the chassis is over sprung, and the shocks cannot properly dampen, the tire is not controlled and can be slipping, causing the 60' time to be slower than expected. The practical is if the shock cannot control the spring and movement of housing, the tire gets too much hit and loads to sidewalls excessively. That overloading will cause the tire to bounce back off the sidewall causing the tire to spin. The amount of spin would vary causing the car to be inconsistent and under perform, in my opinion.

Re: Shock Tech [Re: joshking440] #932044
02/22/11 01:13 PM
02/22/11 01:13 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Actually gents, I have know Eric and the guys at Afco for some time now.

Eric is a good guy and has helped me in every way he can. He is also going to be re-valving my shocks for me to help slow down the violent seperation that is happening in the car.

Once Eric gets his feet wet here, and everyone gets to know him and his product, Im sure we will see more "blue" shocks at the track....


Jason, you get the "A"!!!!!
Im actually suprised wild bill doesnt have a set already, just based on the fact that they are blue!



Re: Shock Tech [Re: MR_P_BODY] #932045
02/22/11 02:52 PM
02/22/11 02:52 PM
Joined: Jun 2009
Posts: 877
ky
68roadrunner Offline
super stock
68roadrunner  Offline
super stock

Joined: Jun 2009
Posts: 877
ky
Quote:

Eric... on a single adjustable shock is the control
valve controlling JUST the extension or does it also
control the compression.... I have a old set of QA-1s
and was told it is only controlling the extension
but they are old.... now I hear a lot of shocks are
controlling both on a single adjustable shock






also on afco shocks that have the single adjustment "window" where you move the adjustment side to side. is this only adjusting extension?

what would be any advantage of replacing the "window" shock with a new double adjustable?

thanks for coming aboard

Re: Shock Tech [Re: autoxcuda] #932046
02/22/11 04:34 PM
02/22/11 04:34 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

Quote:


The 16 and 13 series shocks are expressed in valve numbers.(They are fixed valve shocks)..An example is 1675 or 1375T. The last digit in this case represents the dampening. "5" is typically the mid-point in dampening from soft to stiff. The 32 series shocks are gas charged monotube shocks and are a good shock for hard road racing applications. They are designed for heavy usage and for road racing, will resist fading very well. Any valve code config can be developed in this series of shock. They are adjustable, single or double. The 38 series shocks are initially destined for drag racing...However, we can shape the graph to what is needed. Normally, the series of shocks you list are built with a digressive code for shelf stock...(There are some exceptions though-mostly circle track applications)

..Looking at your dyno graphs, those shocks will be significantly stiffer than OE. Also, they will provide an improvment in performance...I don't think we can determine which end these shocks were built for...Probably built to an application-what someone had some success with for the car they were working on...If you were replacing stock type shocks, these will be a ton better.

Have you ran them? If so, what results did you see?




No, I haven't ran them. The lengths are not right for the front. But probably ok for the rear in terms of physical fit.

When you mentioned 600#s before, is that rebound?

What #'s at 6 IPS would a rear shock starting point be?

With the 32 and 38 series, is there an extra cost associated with custom valving; to make them linear and in the 600# range of adjustability?




Yes, good catch (sorry about this), 600# on the rebound side of the shock.....

Rear shock settings could start at 300#. Again depends on how brave you are??? If you plan to get the most out of it, you may want more control.

Regarding revalve expense, if we have a code established already,(we have many), the charge is modest at $55.00/shock. (Linear would be in this range)...The piston is a different configuration with it's appropriate shim stack.




What #lbs shock would you suggest for a rear shock starting point to go with a 600# front?

Is their a percentage of split general rule of thumb for front to rear shock # for road race applications? Is driving experiance a factor?

I'm no pro driver, I'm on the learning curve.

Does the afco website show the off the shelf adjustment ranges and valving types for the 32 and 38 series pro touring shocks? Or in your catalog?






For your application, I would look for the rear shock to have a full stiff number of 350 at 6 IPS. I haven't found a ratio that applies front to back in shocks....many variables apply.

IMO, as you get more comfortable, you will tend to charge the corners harder which will create a need for more shock dampening...

Hit me with an email and we can share some graphs for your application. eesaffell@afcoracing.com

Re: Shock Tech [Re: 68roadrunner] #932047
02/22/11 04:54 PM
02/22/11 04:54 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Eric... on a single adjustable shock is the control
valve controlling JUST the extension or does it also
control the compression.... I have a old set of QA-1s
and was told it is only controlling the extension
but they are old.... now I hear a lot of shocks are
controlling both on a single adjustable shock






also on afco shocks that have the single adjustment "window" where you move the adjustment side to side. is this only adjusting extension?

what would be any advantage of replacing the "window" shock with a new double adjustable?

thanks for coming aboard




Great questions....on AFCO shocks, the adjustment on the end of the shaft controls the rebound...specifically, the first generation shock had a window that did that job. Counter clockwise (when looking down at the end of shock) made the shock stiffer.....

There are shocks out there that one knob controls both compression and rebound. The philosophy of each company is expressed here in their design...Each company has their beliefs as to the benefits.

To the comparison between first generation and second generation AFCO shocks, there are some refinements.....Friction reduction internally to allow for improved movement, detents on the adjusters for positive adjustment and improved valving...When you gather on-board data and apply that info to the adjustment range, you end up with a shock more closely matched for the application....

Re: Shock Tech [Re: Monte_Smith] #932048
02/23/11 12:03 AM
02/23/11 12:03 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

I have seen Eric mention it a couple times here, but I don't think emphatically enough...........guys the front of the car, HAS TO WORK, before you can do anything with the rear. The front shocks and suspension, are likely just as important, maybe more so, than the rear. I see guys all the time with nice shocks on the rear and junk 3-ways on the front. When the car still won't work, they surmise the good shocks were a waste of money. Got to make the front work.

And while we are talking about front shocks, let me just say that every car out there, does NOT need 7" of travel and loosey goosey shocks in the front. In these days of power, good tires, good tracks and good suspension, a ton of pitch rotation, like was needed in the past, is just not a requirement these days. Most will work with a relatively stiff front setup.

Hey Eric, I know the guys at TRZ had mentioned to you a project I had going on a Holley. Did you ever get a chance to look into that

Thanks

Monte




Monte,

Hit me with the details again on your project. Send it to my email address plz.

Re: Shock Tech [Re: joshking440] #932049
02/23/11 01:02 PM
02/23/11 01:02 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Actually gents, I have know Eric and the guys at Afco for some time now.

Eric is a good guy and has helped me in every way he can. He is also going to be re-valving my shocks for me to help slow down the violent seperation that is happening in the car.

Once Eric gets his feet wet here, and everyone gets to know him and his product, Im sure we will see more "blue" shocks at the track....

Im actually suprised wild bill doesnt have a set already, just based on the fact that they are blue!





Hey Josh, can you re-post the link of your car slapping the wheelie bars? It's the same one you sent to me previously I believe.

This video shows the wheelie bars pounding the track as the car launches. This example is another good place to spend a few minutes... As the wheelie bars hit, they relieve load from the tire contact patch. If too much load is taken away, tire slip or flat out spin can occur. This is a good example of a need for stiffer shocks to properly control the rear housing..If you see this happening to your car, chances are that traction is getting compromised..

What do you guys think? How does this apply to what you are doing?

Re: Shock Tech [Re: EricatAFCO] #932050
02/23/11 01:44 PM
02/23/11 01:44 PM
Joined: Jan 2010
Posts: 803
Idabel,Oklahoma
G
Gary Robbins Offline
super stock
Gary Robbins  Offline
super stock
G

Joined: Jan 2010
Posts: 803
Idabel,Oklahoma
Quote:

Quote:

Actually gents, I have know Eric and the guys at Afco for some time now.

Eric is a good guy and has helped me in every way he can. He is also going to be re-valving my shocks for me to help slow down the violent seperation that is happening in the car.

Once Eric gets his feet wet here, and everyone gets to know him and his product, Im sure we will see more "blue" shocks at the track....

Im actually suprised wild bill doesnt have a set already, just based on the fact that they are blue!





Hey Josh, can you re-post the link of your car slapping the wheelie bars? It's the same one you sent to me previously I believe.

This video shows the wheelie bars pounding the track as the car launches. This example is another good place to spend a few minutes... As the wheelie bars hit, they relieve load from the tire contact patch. If too much load is taken away, tire slip or flat out spin can occur. This is a good example of a need for stiffer shocks to properly control the rear housing..If you see this happening to your car, chances are that traction is getting compromised..

What do you guys think? How does this apply to what you are doing?


What is wheelie bars and why do you need them...1.23 short time best with consistent sub 1.30's with junk single adjustable qa1's on back and double's on front...No bars/28x10.5's/3300#/glide and 3.89 rear gears...And yes that's a real question,why do you need sissy bars and the benifit of them!!!!!!

Re: Shock Tech [Re: Gary Robbins] #932051
02/23/11 02:04 PM
02/23/11 02:04 PM
Joined: Oct 2006
Posts: 4,590
Indy
J
joshking440 Offline
Lunch is on me!
joshking440  Offline
Lunch is on me!
J

Joined: Oct 2006
Posts: 4,590
Indy
Gary, you really know how to hurt a guys feelings....

I truly had the bars on for the first couple outings as I had never driven the car before, and had no idea what it was going to do...but dont worry, I will take them off when im kickin your rear at the moparts race hahahaha.....

Here is the link showing the car slapping the bars, and another view of the car further down track

http://www.youtube.com/watch?v=098GfgWmXuk&feature=related
http://www.youtube.com/watch?v=GY3zKnAUhqQ

Re: Shock Tech [Re: Gary Robbins] #932052
02/23/11 04:45 PM
02/23/11 04:45 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Quote:

Actually gents, I have know Eric and the guys at Afco for some time now.

Eric is a good guy and has helped me in every way he can. He is also going to be re-valving my shocks for me to help slow down the violent seperation that is happening in the car.

Once Eric gets his feet wet here, and everyone gets to know him and his product, Im sure we will see more "blue" shocks at the track....

Im actually suprised wild bill doesnt have a set already, just based on the fact that they are blue!





Hey Josh, can you re-post the link of your car slapping the wheelie bars? It's the same one you sent to me previously I believe.

This video shows the wheelie bars pounding the track as the car launches. This example is another good place to spend a few minutes... As the wheelie bars hit, they relieve load from the tire contact patch. If too much load is taken away, tire slip or flat out spin can occur. This is a good example of a need for stiffer shocks to properly control the rear housing..If you see this happening to your car, chances are that traction is getting compromised..

What do you guys think? How does this apply to what you are doing?


What is wheelie bars and why do you need them...1.23 short time best with consistent sub 1.30's with junk single adjustable qa1's on back and double's on front...No bars/28x10.5's/3300#/glide and 3.89 rear gears...And yes that's a real question,why do you need sissy bars and the benifit of them!!!!!!




Good one Gary! I like all the love I am feeling between you guys on here! LOL.....Seriously, the wheelie/sissy bars do give us a good visual of what is going on with the rear end...If the bars arent' there, we really don't have a frame of reference....So, my question/suggestion is....could your car be experiencing the same conditions? Could there be room for improvement? Back to the test N tune idea. If we don't try something else, we don't know how much better our stuff can be.

Re: Shock Tech [Re: joshking440] #932053
02/23/11 07:16 PM
02/23/11 07:16 PM
Joined: Jan 2010
Posts: 803
Idabel,Oklahoma
G
Gary Robbins Offline
super stock
Gary Robbins  Offline
super stock
G

Joined: Jan 2010
Posts: 803
Idabel,Oklahoma
Quote:

Gary, you really know how to hurt a guys feelings....

I truly had the bars on for the first couple outings as I had never driven the car before, and had no idea what it was going to do...but dont worry, I will take them off when im kickin your rear at the moparts race hahahaha.....

Here is the link showing the car slapping the bars, and another view of the car further down track

http://www.youtube.com/watch?v=098GfgWmXuk&feature=related
http://www.youtube.com/watch?v=GY3zKnAUhqQ


Josh....There's no way i would run a turbo car without bars,seen to many of them do crazy things down track and with your new combo i probaly want be able to hang but i will spray it till i kill it trying...Eric,if my local series allowed bars i would probaly have them on.I don't like to think about how much money i spent on frontends after all the moon shots.No problems now,but it did take lots of testing and shocks did help greatly...I think its great what your doing on the forum with shocks as they are not easily understood,me included and i'm sure i could improve with better shocks and understanding...Gary,oh yea welcome aboard the water is only luke warm here most of the time!!!!!!!!!

Re: Shock Tech [Re: Gary Robbins] #932054
02/23/11 08:11 PM
02/23/11 08:11 PM
Joined: Jan 2003
Posts: 10,009
MN
J
JERICOGTX Offline
I Live Here
JERICOGTX  Offline
I Live Here
J

Joined: Jan 2003
Posts: 10,009
MN
Just want to say Thank You to Eric for sending me a catalog. I had signed up for one on Afco's website, but it wasn't sent. No big deal, but Eric took care of it. Going out of your way, even if it's something simple like that, and all the help here on Moparts, I know where my new set of shock for the RoadRunner will come from now.

Thanks again Eric.

Jeff

Re: Shock Tech [Re: EricatAFCO] #932055
02/23/11 11:06 PM
02/23/11 11:06 PM
Joined: Jul 2009
Posts: 77
Wheatley Arkansas U.S.A.
D
DMCMopar Offline
member
DMCMopar  Offline
member
D

Joined: Jul 2009
Posts: 77
Wheatley Arkansas U.S.A.
Well since we have a discussion going on about shocks does anyone know where I can get a pair of front 90/10s for my F-body 77 Road Runner I would like to find a set.
Thanks Moparts

Re: Shock Tech [Re: DMCMopar] #932056
02/24/11 11:19 PM
02/24/11 11:19 PM
Joined: May 2004
Posts: 2,864
IN
Irun5snd8th Offline
master
Irun5snd8th  Offline
master

Joined: May 2004
Posts: 2,864
IN
Eric, in my conversations with you; you have given me alot of scenarios where cars were not working and what you guys did to fix them. Perhaps, you can share some of that information? I know a couple of those helped me.


AFCO, Rons Fuel Injection sponsored Dodge Challenger Mention Street Lethal Motorsports
Re: Shock Tech [Re: Irun5snd8th] #932057
02/25/11 10:59 AM
02/25/11 10:59 AM
Joined: Jun 2009
Posts: 877
ky
68roadrunner Offline
super stock
68roadrunner  Offline
super stock

Joined: Jun 2009
Posts: 877
ky
eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.

Re: Shock Tech [Re: 68roadrunner] #932058
02/25/11 12:17 PM
02/25/11 12:17 PM
Joined: May 2004
Posts: 2,864
IN
Irun5snd8th Offline
master
Irun5snd8th  Offline
master

Joined: May 2004
Posts: 2,864
IN
Quote:

eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.



It almost sounds to me like the converter is too tight. Follow me here. If the tires are slipping out in the middle and the car picks up; it sounds like the converter is too tight for the setup. Basically the engine is getting into the rpm range that it likes when the tires are slippinng out there.


AFCO, Rons Fuel Injection sponsored Dodge Challenger Mention Street Lethal Motorsports
Re: Shock Tech [Re: Irun5snd8th] #932059
02/25/11 12:37 PM
02/25/11 12:37 PM
Joined: Jun 2009
Posts: 877
ky
68roadrunner Offline
super stock
68roadrunner  Offline
super stock

Joined: Jun 2009
Posts: 877
ky
Quote:

Quote:

eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.



It almost sounds to me like the converter is too tight. Follow me here. If the tires are slipping out in the middle and the car picks up; it sounds like the converter is too tight for the setup. Basically the engine is getting into the rpm range that it likes when the tires are slippinng out there.





thanks eric,
i agree, just wanted any opinions that a simple adjustment might help.

Re: Shock Tech [Re: Irun5snd8th] #932060
02/25/11 01:48 PM
02/25/11 01:48 PM
Joined: Jun 2004
Posts: 2,360
Mobile Alabama
S
SB412DUSTER Offline
top fuel
SB412DUSTER  Offline
top fuel
S

Joined: Jun 2004
Posts: 2,360
Mobile Alabama
Quote:

Quote:

eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.



It almost sounds to me like the converter is too tight. Follow me here. If the tires are slipping out in the middle and the car picks up; it sounds like the converter is too tight for the setup. Basically the engine is getting into the rpm range that it likes when the tires are slippinng out there.







Thats the samething I have seen

Re: Shock Tech [Re: 68roadrunner] #932061
02/25/11 05:20 PM
02/25/11 05:20 PM
Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
Leon441 Offline
master
Leon441  Offline
master

Joined: Nov 2004
Posts: 4,330
Lynchburg, VA
Quote:

eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.




I don't know that I would move the battery. Seems to me it would make the problem worse. If I understand correctly a slick track is a fast track for you. So adding bite with weight or by lowering the top four link bar is going to make the car hook harder and lower the wheel speed. I have some of the same issues but my 60 ft is affected. I run faster with less bite. I tried several converters ranging 1,500 in stall speed. Big stall would get the RPM up but would suffer 60 ft and MPH and stabilize the 60-330 increment. I want to try a tighter converter in my application and take bite out. I think you may have a decent converter just need to get rid of some bite as long as you don't loose 60ft. Just me thinking out loud.

leon


Career best 8.02 @ 169 at 3050# and 10" tires small block power.
Re: Shock Tech [Re: Leon441] #932062
02/25/11 06:46 PM
02/25/11 06:46 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
Quote:

Quote:

eric, i have problem that only a few on this board can relate to.

on my dragster, 4 link rocker arm setup, with the (apparently) first generation afco shocks.

the car worked really good with previous owners setup 565 bbc and glide, mine is a 499 mopar/glide.

the car 60s pretty consistent, but the 60-330 #s change. when the track is hot and slick it actually runs quicker. i jetted the carb up and rulled out fuel. lowered top bar in the front with no change.

ideas on shock adjustments here, or replacement of shock is possible.


my ideas for this spring, move battery out of nose, to put more weight on rear tires, raise launch chip from 4600, add more rear gear from 4.10 to 4.29 to hit tire harder.

any ideas appreciated.




I don't know that I would move the battery. Seems to me it would make the problem worse. If I understand correctly a slick track is a fast track for you. So adding bite with weight or by lowering the top four link bar is going to make the car hook harder and lower the wheel speed. I have some of the same issues but my 60 ft is affected. I run faster with less bite. I tried several converters ranging 1,500 in stall speed. Big stall would get the RPM up but would suffer 60 ft and MPH and stabilize the 60-330 increment. I want to try a tighter converter in my application and take bite out. I think you may have a decent converter just need to get rid of some bite as long as you don't loose 60ft. Just me thinking out loud.

leon




I would think he would need to lower the IC but still
maintain about the same IC length... with the lower
IC it hits the tire less BUT holds the hit longer
so I would have to ask what is the IC length and height
now... with lowering the top bar all you did was
shorten the IC length which does lift more weight
from farther back

Re: Shock Tech [Re: MR_P_BODY] #932063
02/25/11 07:05 PM
02/25/11 07:05 PM
Joined: Jun 2009
Posts: 877
ky
68roadrunner Offline
super stock
68roadrunner  Offline
super stock

Joined: Jun 2009
Posts: 877
ky


I would think he would need to lower the IC but still
maintain about the same IC length... with the lower
IC it hits the tire less BUT holds the hit longer
so I would have to ask what is the IC length and height
now... with lowering the top bar all you did was
shorten the IC length which does lift more weight
from farther back






mr p cant remember exactly and cant get to my book right now. it is at 3-4" off the ground and maybe 40-50" out, with bar one hole higher it was -1to-2" at around 80" i think. the change made no difference

thanks for the help guys

Re: Shock Tech [Re: 68roadrunner] #932064
02/25/11 07:13 PM
02/25/11 07:13 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
mr p cant remember exactly and cant get to my book right now. it is at 3-4" off the ground and maybe 40-50" out, with bar one hole higher it was -1to-2" at around 80" i think. the change made no difference

thanks for the help guys




Can you get a point thats about the same IC length
but lower... you showed lower but that was 30" longer

Re: Shock Tech [Re: MR_P_BODY] #932065
02/25/11 07:20 PM
02/25/11 07:20 PM
Joined: Jun 2009
Posts: 877
ky
68roadrunner Offline
super stock
68roadrunner  Offline
super stock

Joined: Jun 2009
Posts: 877
ky
Quote:

mr p cant remember exactly and cant get to my book right now. it is at 3-4" off the ground and maybe 40-50" out, with bar one hole higher it was -1to-2" at around 80" i think. the change made no difference

thanks for the help guys




Can you get a point thats about the same IC length
but lower... you showed lower but that was 30" longer





i am sure i can, will have to try it when i get it out, i do see what you and everyone here is saying. actually to much bit for the setup. if you tighten the extension on the shock would that help, or make unmanagable?

Re: Shock Tech [Re: 68roadrunner] #932066
02/25/11 07:30 PM
02/25/11 07:30 PM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
Master
MR_P_BODY  Offline
Master

Joined: Jun 2003
Posts: 52,972
Romeo MI
i am sure i can, will have to try it when i get it out, i do see what you and everyone here is saying. actually to much bit for the setup. if you tighten the extension on the shock would that help, or make unmanagable?




You normally tighten it on a good track and soften
it for a bad track so in your case maybe that would
help but I cant see it doing much down track so I
will let someone else like Eric make comment on that

Re: Shock Tech [Re: MR_P_BODY] #932067
02/25/11 07:45 PM
02/25/11 07:45 PM

A
Anonymous
Unregistered
Anonymous
Unregistered
A



Did you guys over there at AFCO ever get those reducer bushings for your front double adjustable shocks. The lower bolt holes are too large for stock front ends on these mopars.You needed to get reducers to put in the lower hole to make the stock bolt work with your shocks.
I'm in the market for another set of double adjustables

Re: Shock Tech [Re: MR_P_BODY] #932068
02/26/11 10:10 AM
02/26/11 10:10 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

i am sure i can, will have to try it when i get it out, i do see what you and everyone here is saying. actually to much bit for the setup. if you tighten the extension on the shock would that help, or make unmanagable?




You normally tighten it on a good track and soften
it for a bad track so in your case maybe that would
help but I cant see it doing much down track so I
will let someone else like Eric make comment on that





In my experience, as you move down the track, shocks have less effect on the chassis. Certainly by the 330, the shocks are just enjoying the ride. Mr P, I agree with your tuning tips above. Excessive bite can distort the tire on the leave and will stay that way until torque falls off just enough to allow the tire to begin to get "round" again.

Remember, what we see at the sidewall is very similar to what is happening at the contact patch. Wrinkles are occuring. We could be talking about the tires loosing enough contact patch from hitting them too hard that they rotate some...

If I remember the conversation correctly (in this case), lowering the upper bar one hole, (which should have created more hit or bite) did not fix the problem. >>>>Did it make it worse??????

A bar change will be a larger change than a shock adjustement so if the bar angle change didn't make the problem worse, the problem probably isn't related to bite.

I have seen converters that are broken causing issues with traction. If you have a back up converter or can borrow one that is similar, you may R & D converters to eliminate that component, then move on if you don't see results...

Re: Shock Tech #932069
02/26/11 10:19 AM
02/26/11 10:19 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Did you guys over there at AFCO ever get those reducer bushings for your front double adjustable shocks. The lower bolt holes are too large for stock front ends on these mopars.You needed to get reducers to put in the lower hole to make the stock bolt work with your shocks.
I'm in the market for another set of double adjustables




Keith,

We have it covered. A step bushing is the simple fix. If your car leaves wheels up and lands with a bounce, bounce, we may consider the bounce control valving (BNC). That valving option is available in any shock. The catalog and site shows some applications for the BNC valving but remember that any valving option can be added to a shock.

Re: Shock Tech [Re: Irun5snd8th] #932070
02/26/11 10:48 AM
02/26/11 10:48 AM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Eric, in my conversations with you; you have given me alot of scenarios where cars were not working and what you guys did to fix them. Perhaps, you can share some of that information? I know a couple of those helped me.




Eric,

One thing that has repeatedly helped that bears mentioning is measuring shock travel. The chassis needs a specific amount of shock travel to work. The key is to find out how much.

To begin, we have to be able to measure movement in both directions. The extension is more difficult to capture. Check out the pic below. The rings install between the spring and coil over hardware. The rod is fixed on one end and slides thru the ring on the other end. Rubber grommets are fixed on both sides of the tab on the slide ring. As the rod goes thru, the rubber grommet gets pushed (in either direction) so we can measure distance.

Start with logging shock travel. Make several passes to build your baseline. Through this process, you will begin to determine which passes were better. Begin to begin a relationship between a good pass and shock travel. As data builds, you should be able to hone in.

So, if you make a pass that is less than stellar, (be it at the home track or if you unload at another track), look both at the 60' time and your shock travel. If the 60' was slow, and you think it spun, chances are that shock travel will be reduced from your target distance. You now have better info to work with.

Remembering that we have good shocks that make a difference when we click them, we can soften the extension/rebound to allow for more hit in the rear..Also, consider the front end is there too...(Monte) You can soften up extension on the front and/or give the front end more travel to promote more pitch rotation. Make your adjustment and evaluate the results.

Various professional teams with high end data gathering equipment on board use shock travel info to evaluate tuning possibilities. As sportsman racers, we have similar tools to put in play for us.

Here is a link to a high res imageof the travel indicator;

www.afabcorp.com/AFCO/Shock%20Accessories/pages/20116_500.html

Re: Shock Tech [Re: EricatAFCO] #932071
03/01/11 02:46 AM
03/01/11 02:46 AM
Joined: Nov 2008
Posts: 660
San Diego
formula S Offline
mopar
formula S  Offline
mopar

Joined: Nov 2008
Posts: 660
San Diego
Got some 10" springs with .437 wire dia, what is my spring rate?

Re: Shock Tech [Re: formula S] #932072
03/01/11 02:49 AM
03/01/11 02:49 AM
Joined: Jun 2004
Posts: 2,360
Mobile Alabama
S
SB412DUSTER Offline
top fuel
SB412DUSTER  Offline
top fuel
S

Joined: Jun 2004
Posts: 2,360
Mobile Alabama
Quote:

Got some 10" springs with .437 wire dia, what is my spring rate?





He will probally need to know the number of active coils to tell you the rate

Re: Shock Tech [Re: SB412DUSTER] #932073
03/02/11 05:28 PM
03/02/11 05:28 PM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
master
dvw  Offline
master

Joined: Mar 2006
Posts: 9,791
MI, usa
Front shock question. With a double adjustable,under what conditions would a softer compression setting be required? I've been led to believe with my type of car it would be tough to have the compression to stiff. The car is still in the build stage. 64 Belvedere,aprox 3350 w/driver,36" ladder bar,10.5Wx31,4.10,Koni dbl adj rear w/130lb spring,113" wheel base,foot brake, 572" (850-900 H.P.?) 727 auto, 2.45 1st gear. Based on my old car I would say Frt weight 52%. With my nose weight would a single with stiff compression valving work? Or should I sell them and step up to doubles in the front. This will be a index car (9.25 or 9.50) so consistancy is important.
Thanks Doug

Re: Shock Tech [Re: EricatAFCO] #932074
03/03/11 12:59 AM
03/03/11 12:59 AM
Joined: Dec 2009
Posts: 151
ohio
R
Rich970 Offline
member
Rich970  Offline
member
R

Joined: Dec 2009
Posts: 151
ohio
hi Eric i have a 2800 # 4 speed , ladder bar car . single adj rear shocks ride height set at 13 1/4 " 95# 12" springs and set soft 3 clicks lh and 4 r.h. shock are 11 5/8" comp and 17" extended. it rolls to the right pretty good could it be the l.h. shock could extend enough to unload the l.h. slick ? it was worn to the cords at the end of season r.h. had 3/32 left.

6507173-DSC00253.JPG (217 downloads)
Last edited by Rich970; 03/03/11 01:02 AM.
Re: Shock Tech [Re: Rich970] #932075
03/04/11 12:14 AM
03/04/11 12:14 AM
Joined: Feb 2003
Posts: 240
Pottstown, Pa.
S
sg1093 Offline
enthusiast
sg1093  Offline
enthusiast
S

Joined: Feb 2003
Posts: 240
Pottstown, Pa.
I have a question for Eric. I have been racing a 69 AMX in Super Stock. I have modified the upper and lower control arms and strut rods. I have modified a set of Koni Spa 1 69 Camaro front shocks to fit but I am out of extension. I would like to modify the lower mount to fit a Afco adjustable front shock for a A Body Mopar. Has anyone else tried this? The stock AMX shock has studs like the upper mount of a A Body shock at the top and bottom. Thank you, Pat

Last edited by sg1093; 03/04/11 12:23 AM.
Re: Shock Tech [Re: SB412DUSTER] #932076
03/04/11 08:07 PM
03/04/11 08:07 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Quote:

Got some 10" springs with .437 wire dia, what is my spring rate?





He will probally need to know the number of active coils to tell you the rate




We need to know a few things...... We need the number of active coils (total of coils less 2 for the end coils), also, we need to know the material used to make the coils. Different materials have different tensil strength etc. If we can get that info, we could plug that info in and see what we get. Although, the only truth is a good spring checker. Springs can degrade. The formula method estimates the springs at 100%

Re: Shock Tech [Re: dvw] #932077
03/04/11 08:19 PM
03/04/11 08:19 PM
Joined: Feb 2011
Posts: 43
IN
E
EricatAFCO Offline OP
member
EricatAFCO  Offline OP
member
E

Joined: Feb 2011
Posts: 43
IN
Quote:

Front shock question. With a double adjustable,under what conditions would a softer compression setting be required? I've been led to believe with my type of car it would be tough to have the compression to stiff. The car is still in the build stage. 64 Belvedere,aprox 3350 w/driver,36" ladder bar,10.5Wx31,4.10,Koni dbl adj rear w/130lb spring,113" wheel base,foot brake, 572" (850-900 H.P.?) 727 auto, 2.45 1st gear. Based on my old car I would say Frt weight 52%. With my nose weight would a single with stiff compression valving work? Or should I sell them and step up to doubles in the front. This will be a index car (9.25 or 9.50) so consistancy is important.
Thanks Doug




Some cars can use single adjustable shocks on the front and be fine. The size of the wheelie and the weight are probably the main factors. The double adjustable shock offers the most tuning options. We have had success using either shock on the appropriate application. How high does your car pick them up and carry them out?

Re: Shock Tech [Re: EricatAFCO] #932078
03/04/11 09:34 PM
03/04/11 09:34 PM
Joined: May 2008
Posts: 1,131
Thigh-Gap Junction
@
@#$%&*! Offline
New user name, Same old jerk!
@#$%&*!  Offline
New user name, Same old jerk!
@

Joined: May 2008
Posts: 1,131
Thigh-Gap Junction
Quote:

Quote:

Got some 10" springs with .437 wire dia, what is my spring rate?




We need to know a few things...... We need the number of active coils (total of coils less 2 for the end coils), also, we need to know the material used to make the coils. Different materials have different tensil strength etc. If we can get that info, we could plug that info in and see what we get. Although, the only truth is a good spring checker. Springs can degrade. The formula method estimates the springs at 100%




Actually, material strength doesn't enter into it at all. The web is loaded with plenty of coil spring rate calculators but the one at Wallaceracing.com will do: http://www.pontiacracing.net/js_coil_spring_rate.htm


Re: Shock Tech [Re: EricatAFCO] #932079
03/05/11 12:09 AM
03/05/11 12:09 AM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
master
dvw  Offline
master

Joined: Mar 2006
Posts: 9,791
MI, usa
Quote:

Quote:

Front shock question. With a double adjustable,under what conditions would a softer compression setting be required? I've been led to believe with my type of car it would be tough to have the compression to stiff. The car is still in the build stage. 64 Belvedere,aprox 3350 w/driver,36" ladder bar,10.5Wx31,4.10,Koni dbl adj rear w/130lb spring,113" wheel base,foot brake, 572" (850-900 H.P.?) 727 auto, 2.45 1st gear. Based on my old car I would say Frt weight 52%. With my nose weight would a single with stiff compression valving work? Or should I sell them and step up to doubles in the front. This will be a index car (9.25 or 9.50) so consistancy is important.
Thanks Doug




Some cars can use single adjustable shocks on the front and be fine. The size of the wheelie and the weight are probably the main factors. The double adjustable shock offers the most tuning options. We have had success using either shock on the appropriate application. How high does your car pick them up and carry them out?



Not sure as the car is being completed as we speak. What would be the indications/results of the front shock compression setting being to stiff?
Doug

Re: Shock Tech [Re: dvw] #932080
03/09/11 11:05 AM
03/09/11 11:05 AM
Joined: May 2004
Posts: 2,864
IN
Irun5snd8th Offline
master
Irun5snd8th  Offline
master

Joined: May 2004
Posts: 2,864
IN
Being too stiff up there at minimum I would expect the front tires to take more of a blow which would distort them and hurt performance. Even if ever so slightly. I would expect the car to be more prone to bounce as well from the front tires, kind of like airing up a basketball too much. Thats an exagerration but illustrates the point. I have never tried running the compression really stiff on the front so I can speak to this only in theory.


AFCO, Rons Fuel Injection sponsored Dodge Challenger Mention Street Lethal Motorsports
Page 1 of 6 1 2 3 4 5 6






Powered by UBB.threads™ PHP Forum Software 7.7.1