Suspension Setup

[jcarius]

Folks,

Well, the last short course race was a bit hard on our car. I need some tips on things to try as far as rear suspension setup.

The big symptom: We hit a sharp, sudden bump on the course (think speed bump). The rear suspension bottoms on the stop then fully extends and the rear tires leave the ground, then the car hits and near bottoms out again. It then stabilizes.

Things I can play with:

Rear torsion preload: if I increase preload, it will be more resistent to the bump in hte first place, but will it tend to make the rear end "kick" more after the bump?

Shock Valving: Any ideas?

Shock position: This is an old car, and the shock mounts may not be optimal. I figure that I want the spring plate and the shock to be at a 90 degree angle at full bump, correct?

Any help would be terrific.

Thanks,

Jim & Vanessa
VORRA 955

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[Protech975]

J&V - I'll try to help with what I know but need some basic info? What type car do you have, Single or Two seat? How much does it weigh? What size T-bars are you running? Adjusters? and what size and type shocks do you run?
It's all a matter of balance and just a small adjustment front to rear can make a big differance! Just tweaking the bars will probably not help as it has more to do with balance of the shocks and their valving than anything but without the total package specs it would be very hard to even guess. Thanks Rob S.

[jcarius]

The car is about 1650 lbs (I know, I need to shave some weight) in a single seat T-MAG chassis. 26mm bars- no adjusters, Fox 2" shocks front and rear (I'll check the valving when I get home tonight.) The first thing I really need to know, is from a shock mounting standpoint, how to determine the best angle for the rear shocks to sit at.

Thanks!

Jim

[jcarius]

Ok, corrects and additions to my last post. Weight is 1745 lbs - like I said too durn heavy - but I've got to live with that right now. Bars are 27mm not 26, and are 24 11/16" long. Rear shocks are valved 55/80, front are unknown.

Thanks again,

Jim

[The Doctor]

it sounds like you may need more rebound in the shocks.You may also have to much preload on the torrsions.You need to set up the car so that the camber on the rear wheels is about 0 on the short course and make the shocks do most of the work.