|
Re: cal trac top hole vs bottom
[Re: BradH]
#2556987
10/01/18 01:03 PM
10/01/18 01:03 PM
|
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
I raced my car again this weekend and it was hooking really well, but doesn't 60 ft. like it did with SS springs.
The car leaves smoother and more level and felt really good, though.
It had done a best of 1.54 60 ft. with SS springs but not consistently. It did 1.67 all day long with the Cal-Trac setup last Saturday. I have 3.54 gears ET Street Pro's and leave off idle. The engine is like a low rpm diesel and makes massive torque.
I use the Calvert (Rancho) 9 position shocks set on 7. We did change the upper mount on the shocks to get them more vertical.
The car drives excellent but I would really like to shave a tenth off consistantly.
Should I move the bar to the upper hole? I thought about rear sliders, too, but use the car a lot on the street and have heard they are noisy.
Will double adjustable shocks help?
The only way to find out what your combination and car likes the best is to test, test, and then test some more   Have you tested leaving at different RPM yet? If not try that also  x2 on Cab's comments. I ran a best of 1.54 on SS springs, then switched to CalTracs with standard leaf springs and the same Rancho 5-way dampers I was using with the SS springs and dropped to a best of 1.51 and more consistency. Better engine and changing to split mono-leaf springs saw a best of 1.45, and still with the same old-style Ranchos. But there were preload & damping adjustments, launch RPM changes, tire pressure changes, etc., along the way. Two things came to mind that I wanted to bring up: 1. I've never tried the upper hole since switching to CalTracs. 2. However, until this rebuild, I've always had the shorter 20" SS/A-body front segments on my E-body, rather than the standard 22" front segment. With the switch to the Strange S-60, I also put 22" fronts on the car. How would increasing the front section & bar length by 2" likely change the settings?
|
|
|
Re: cal trac top hole vs bottom
[Re: Stroker Scamp]
#2557034
10/01/18 02:28 PM
10/01/18 02:28 PM
|
Joined: May 2006
Posts: 1,260
New Mexico
Adobedude
pro stock
|
pro stock
Joined: May 2006
Posts: 1,260
New Mexico
|
I race a low 11 second Dodge Dakota on a [censored] track, traction has always been an issue. I have relocated DA viking shocks, Monoleafs, catracs, spring sliders...And instant spin.
A local 8.5 my got my truck from blowing the tires off to lifting the fronts an inch in four passes...I was bottom hole, no preload he moved me to upper hole with 1.5 TURNS preload with shock changes front and rear.
I'm still going to 14" tires and a 4 link...I'll be making more power next year with a looser converter and launching off a brake.
In summary...video tape your launch and play it back in slow motion, only way to see what is happening.
2001 Dodge Dakota
408 All Motor
11.27 @ 117.83 mph
2017 NM Mopar Challenge Series Champion.
|
|
|
Re: cal trac top hole vs bottom
[Re: cudaman1969]
#2557118
10/01/18 04:40 PM
10/01/18 04:40 PM
|
Joined: Aug 2006
Posts: 610
long time lurker, short time p...
PorkyPig
mopar
|
mopar
Joined: Aug 2006
Posts: 610
long time lurker, short time p...
|
Does this look right, or should I be on bottom hole?
Do you have shims-spacers between spring and housing-perch? Perch sitting on the spring I mean?
No, I don't have any spacers or shims. Not sure what difference that would make?
Raising or lowering that bottom plate in relation to the housing changes the instant center just like the first or second hole in the front pivot. Pretty much the same way moving the bottom bar in a four link at the housing. One way of getting the bar level to ground and the farther away the hole is from the center of housing, more leverage, closer, less I never thought about adding a spacer to lower the rear hole position relative to the axle. I know the Assassin bars have a lot of adjustment holes up front and in back but think so many options could lead to more confusion on how to set it up.
|
|
|
Re: cal trac top hole vs bottom
[Re: PorkyPig]
#2557180
10/01/18 06:58 PM
10/01/18 06:58 PM
|
Joined: Jul 2004
Posts: 19,317
State of confusion
Thumperdart
I Live Here
|
I Live Here
Joined: Jul 2004
Posts: 19,317
State of confusion
|
Does this look right, or should I be on bottom hole?
Do you have shims-spacers between spring and housing-perch? Perch sitting on the spring I mean?
No, I don't have any spacers or shims. Not sure what difference that would make?
Raising or lowering that bottom plate in relation to the housing changes the instant center just like the first or second hole in the front pivot. Pretty much the same way moving the bottom bar in a four link at the housing. One way of getting the bar level to ground and the farther away the hole is from the center of housing, more leverage, closer, less I never thought about adding a spacer to lower the rear hole position relative to the axle. I know the Assassin bars have a lot of adjustment holes up front and in back but think so many options could lead to more confusion on how to set it up. A few racers I know swear by the Assasin bars but agree, the Calvert stuff is on some fast stuff and to add to this, Calvert has recommended the bar parallel to the ground also as a starting point.......I think you guys may be on to something and I will try the upper hole on the street, then install Shilo's ft. Vikings and do a few 60's to see how it acts then one full boogie............
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....
|
|
|
Re: cal trac top hole vs bottom
[Re: dizuster]
#2557241
10/01/18 08:49 PM
10/01/18 08:49 PM
|
Joined: Dec 2013
Posts: 4,663
Wichita
GY3
master
|
master
Joined: Dec 2013
Posts: 4,663
Wichita
|
Unless something is severely under powered, I personally don't ever see the need to use the lower hole. I think it's better to get the bar as stiff as possible, as quickly as possible... and use the shock to control the hit.
GY3... when you say shock settings are at 7, do you mean 7 clicks from full tight? What front shocks do you have on it? In the 60ft range you're in, I would definitely move to the upper hole.
I suggest moving to the upper hole and continue to click the shocks tighter 2 clicks at a time. The car will pick up 60ft as you do it until it gets to a point where it spins. Then back them off 1 click. That will get you close...
From there it's a balance of rear shock setting and front shock setting to optimize further. I am at two clicks from Full tight. I did 9 for a while which is the fully tight setting and it spun a little. My main problem is the track prep goes away quickly at a Friday night Grudge night because of all the super hard street tires pulling up the prep and the rubber. Going to get some hits in on a decent track in the next few months and we'll see what happens. Definitely going to try the top hole but probably won't get to it until next season.
'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.
|
|
|
Re: cal trac top hole vs bottom
[Re: dizuster]
#2557320
10/01/18 11:35 PM
10/01/18 11:35 PM
|
Joined: Jan 2015
Posts: 493
Parts unknown
590 Challenger
mopar
|
mopar
Joined: Jan 2015
Posts: 493
Parts unknown
|
Unless something is severely under powered, I personally don't ever see the need to use the lower hole. I think it's better to get the bar as stiff as possible, as quickly as possible... and use the shock to control the hit.
GY3... when you say shock settings are at 7, do you mean 7 clicks from full tight? What front shocks do you have on it? In the 60ft range you're in, I would definitely move to the upper hole.
I suggest moving to the upper hole and continue to click the shocks tighter 2 clicks at a time. The car will pick up 60ft as you do it until it gets to a point where it spins. Then back them off 1 click. That will get you close...
From there it's a balance of rear shock setting and front shock setting to optimize further. You seem to have a ton of knowledge on this subject. My car I just put together with no real adjustments. Ran 1.12 1.13 last year. I added maybe another half a thousand horsepower this year and I can't get it off the line. Same shock settings, they spray fresh glue for me and drag the track, I leave with only 2 degrees of total timing, bringing it up to 3 degrees in .6 seconds. I have been told the hit is just way to hard, caltrac bar is about parallel with the ground. I have been thinking today maybe lowering it to the bottom hole to slow down that first motion. It will probably point downward. I seen you say all the fastest cars use top.....I have Santuff' on the rear, but have been told "The shock adjustment won't affect the initial" Please help if you can
|
|
|
Re: cal trac top hole vs bottom
[Re: Thumperdart]
#2574695
11/06/18 01:54 AM
11/06/18 01:54 AM
|
Joined: Aug 2006
Posts: 610
long time lurker, short time p...
PorkyPig
mopar
|
mopar
Joined: Aug 2006
Posts: 610
long time lurker, short time p...
|
Does this look right, or should I be on bottom hole?
Do you have shims-spacers between spring and housing-perch? Perch sitting on the spring I mean?
No, I don't have any spacers or shims. Not sure what difference that would make?
Raising or lowering that bottom plate in relation to the housing changes the instant center just like the first or second hole in the front pivot. Pretty much the same way moving the bottom bar in a four link at the housing. One way of getting the bar level to ground and the farther away the hole is from the center of housing, more leverage, closer, less I never thought about adding a spacer to lower the rear hole position relative to the axle. I know the Assassin bars have a lot of adjustment holes up front and in back but think so many options could lead to more confusion on how to set it up. A few racers I know swear by the Assasin bars but agree, the Calvert stuff is on some fast stuff and to add to this, Calvert has recommended the bar parallel to the ground also as a starting point.......I think you guys may be on to something and I will try the upper hole on the street, then install Shilo's ft. Vikings and do a few 60's to see how it acts then one full boogie............ Any thoughts about how lowering the rear pivot point by adding a spacer between the spring and the mount would act differently than going to the top front hole from the bottom? Both ways would make the Caltracs hit quicker.
|
|
|
Re: cal trac top hole vs bottom
[Re: PorkyPig]
#2574734
11/06/18 09:02 AM
11/06/18 09:02 AM
|
Joined: Jan 2003
Posts: 2,915
A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,915
A shed in England
|
Any thoughts about how lowering the rear pivot point by adding a spacer between the spring and the mount would act differently than going to the top front hole from the bottom? Both ways would make the Caltracs hit quicker. I can vouch that adding a 1" spacer 'tween axles and spring will hit the tyre harder and increase axle rotation. Top hole on front bracket always hits harder so much that it will likely "wad up" a std bias ply. Front travel is also important on how it hits, less front travel will cause porpoising (load and unload of the rear) but this is also dependant upon Hp/Torque and weight. Tubes and Stiff sidewalls will help but my Caltrac setup works great on Radial tyres. This is what has happened on my car, in a nutshell as I've been running Caltracs since 2001. Though your results may vary 
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: cal trac top hole vs bottom
[Re: BradH]
#2575737
11/08/18 06:34 AM
11/08/18 06:34 AM
|
Joined: Jan 2003
Posts: 2,915
A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,915
A shed in England
|
Tig - I see that you run a spacer under the spring, but what hole do you use up front? Bottom Hole, hit is hard to control otherwise. The big gun Afco's ran out of extension damping even on the bottom hole. They couldn't control the rise and would wad up the bias ply's bad. I got them re-valved... for Radials. I'm quickly finding out that's a different ball game but so far the cars 60ft is way better, once we go forward instead of up, I think we could go hi 1.20's
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
Re: cal trac top hole vs bottom
[Re: Tig]
#2575842
11/08/18 01:17 PM
11/08/18 01:17 PM
|
Joined: Oct 2011
Posts: 3,036
bean town ....Ca
WHITEDART
master
|
master
Joined: Oct 2011
Posts: 3,036
bean town ....Ca
|
This is a slow motion video of a 1.19. Short time menscer rear shocks Calvert mono leaf.. Cal track bar in lower hole.. with the preload set to make the car go straight.. https://youtu.be/ddVLS0nreuM.
In the 8s N/A.with Brett miller W8's
5.07 at 133 at 2700lb
|
|
|
Re: cal trac top hole vs bottom
[Re: WHITEDART]
#2575891
11/08/18 02:43 PM
11/08/18 02:43 PM
|
Joined: Jan 2003
Posts: 2,915
A shed in England
Tig
master
|
master
Joined: Jan 2003
Posts: 2,915
A shed in England
|
This is a slow motion video of a 1.19. Short time menscer rear shocks Calvert mono leaf.. Cal track bar in lower hole.. with the preload set to make the car go straight.. https://youtu.be/ddVLS0nreuM. Bias ply slicks I'm guessing??
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials.
9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge.
RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
|
|
|
|
|
