Roll couple and rear tire spin |
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Roll couple and rear tire spin |
yeahmag |
Feb 19 2018, 06:09 PM
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#1
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Advanced Member Group: Members Posts: 2,422 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California |
Just got through my first autocross after the rebuild and the car was great! With a good friend and hot-shoe behind the wheel the car was the 2nd fastest aircooled car and #7 PAX adjusted in a pretty big field (PCA OCR).
I'd like to get better control of the rear, inner tire. We were spinning it up quite a bit. I'm thinking more rear spring is the correct approach. Current set up: Front: 21mm torsion bars 19mm sway bar set 3/4 hard Rebel Racing Bushings Monoball camber plates 19mm raised spindles Bilstein Sports 2.5 degrees camber 5 degrees caster 1/16" toe out Rear 225lb springs Rebel Racing Bushings No rear bar Koni Yellows (full soft) 2.0 degrees camber 1/16" toe in Tires are fairly used up Hankook C71 Z214 in a square set up (205/50-15) run at about 22lbs hot. Granted replacing the tires would help, but even when they were new it would spin these up. I have 275lb springs sitting around that I can swap in. Am I heading in the right direction? Me https://www.youtube.com/watch?v=hdMUYqusga4 Evan (damn he's fast) https://www.youtube.com/watch?v=mI6O_gVzPuA |
yeahmag |
Feb 20 2018, 12:45 AM
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#2
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Advanced Member Group: Members Posts: 2,422 Joined: 18-April 05 From: Pasadena, CA Member No.: 3,946 Region Association: Southern California |
The idea is to keep the wheel with the weight on it from compressing too far. This works opposite of a roll bar that will tend to pick up the inside wheel.
There is some fairly good discussions on this and my guess is it really only works if you don't have an under/over steer problem (and likely to only work if excluding the roll bar from the equation - which I don't run on the rear). The car is fairly neutral and rotates ok, but feels "wallowy" in the rear. One big change is that I'm now Rebel Racing Teflon bushings in the rear. I've heard rumors going from poly/delrin to a better bushing (Rebel/Elephant) you need to increase your spring rate to counteract the lack of drag from the lesser bushings. |
ChrisFoley |
Feb 20 2018, 01:41 PM
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#3
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I am Tangerine Racing Group: Members Posts: 7,928 Joined: 29-January 03 From: Bolton, CT Member No.: 209 Region Association: None |
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