Re: Shock Tech
[Re: HEMIFRED]
#931989
02/19/11 12:08 AM
02/19/11 12:08 AM
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Posts: 27,596 So Cal
autoxcuda
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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
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Re: Shock Tech
[Re: moparniac]
#931990
02/19/11 12:17 AM
02/19/11 12:17 AM
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Joined: Oct 2006
Posts: 4,590 Indy
joshking440
Lunch is on me!
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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.....
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Re: Shock Tech
[Re: joshking440]
#931993
02/19/11 12:58 AM
02/19/11 12:58 AM
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Joined: Feb 2011
Posts: 43 IN
EricatAFCO
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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?
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Re: Shock Tech
[Re: moderncylinder]
#931995
02/19/11 01:09 AM
02/19/11 01:09 AM
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Joined: Feb 2011
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EricatAFCO
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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.
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Re: Shock Tech
[Re: EricatAFCO]
#931996
02/19/11 01:17 AM
02/19/11 01:17 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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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
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Re: Shock Tech
[Re: greendart408]
#931997
02/19/11 01:17 AM
02/19/11 01:17 AM
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EricatAFCO
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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...
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Re: Shock Tech
[Re: EricatAFCO]
#931998
02/19/11 01:18 AM
02/19/11 01:18 AM
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Joined: Dec 2007
Posts: 10,542 BROOK PARK, OH
WILD BILL
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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.
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Re: Shock Tech
[Re: cheapstreetdustr]
#931999
02/19/11 01:19 AM
02/19/11 01:19 AM
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EricatAFCO
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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
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Re: Shock Tech
[Re: fourgearsavoy]
#932000
02/19/11 01:23 AM
02/19/11 01:23 AM
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Joined: Feb 2011
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EricatAFCO
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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?
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Re: Shock Tech
[Re: EricatAFCO]
#932001
02/19/11 01:31 AM
02/19/11 01:31 AM
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Joined: Jan 2003
Posts: 27,596 So Cal
autoxcuda
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So Cal
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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 01:57 AM.
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Re: Shock Tech
[Re: MR_P_BODY]
#932002
02/19/11 01:31 AM
02/19/11 01:31 AM
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Joined: Feb 2011
Posts: 43 IN
EricatAFCO
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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.
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Re: Shock Tech
[Re: EricatAFCO]
#932003
02/19/11 01:35 AM
02/19/11 01:35 AM
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Joined: Jun 2003
Posts: 9,225 Charleston
sixpackgut
Drag Week Mod Champion
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Posts: 9,225
Charleston
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Quote:
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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
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Re: Shock Tech
[Re: autoxcuda]
#932004
02/19/11 01:55 AM
02/19/11 01:55 AM
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Joined: Feb 2011
Posts: 43 IN
EricatAFCO
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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.
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Re: Shock Tech
[Re: EricatAFCO]
#932005
02/19/11 02:14 AM
02/19/11 02:14 AM
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Joined: Jan 2003
Posts: 27,596 So Cal
autoxcuda
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 27,596
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 01:23 PM.
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Re: Shock Tech
[Re: sixpackgut]
#932006
02/19/11 08:23 AM
02/19/11 08:23 AM
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Joined: Feb 2007
Posts: 6,295 U.S.
moparniac
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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
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