Rear suspension

[Barry]

Measured car at all wheelwells all are 27.5 inches except for
rear right side which is 28.25! My car is a 1981 with 50,000 kms.
gymkhana syspension.Anyone else have this trouble?
Also is the composite rear spring a good mod to make as for ride and performance compared to the gymkhana suspension?

Barry

 

[AKRAY4PLAY]

Barry,
i bought the performance plus suspention kit from VetteBrakes. i have not had a chance to drive the car yet, waiting to dyno then install my new motor. the guys at VetteBrakes were very helpfull and seemed to ask all the right questions. they have several options to apply to the kit to meet your needs. the front and rear composite-mono kit ran $1900 for me, and i think the '81 priced out at $2000. it comes with everything!! all poly, new strut rods, ball joints, a-arms, swaybars, etc. the only thing you'll have stock front or rear is the power steering and the trailing arms. they do offer just the rear spring kit for around $350. a friend of mine put the rear kit on his '76 and loves it. i have heard a couple of guys say it works very well. i do know the suspension is very adjustable. you can adjust just the ride height, ride height and spring rate or just spring rate in about a half an hour. the kit is a snap to install and fit and finish is top knotch. as for your weird ride height, sorry i can't offer any suggestions other than check your spring bolt adjustments and look for any other signs of damage under that rear. i think the car is supposed to sit one inch higher in the rear, but don't quote me on that. check out the VetteBrakes website, it is not very good, but the catalog they offer is very detailed and informative. best of luck to you, brian

http://vettebrakes.com/

 

[69MyWay]

Welcome

Berry, Welcome to CACC. I hope you find this a great source of information and community.

It is interesting you note this problem. The truth is, it may simply be the spring, and or it could be a dozen other things.

1. The quarter panels may have been bonded unequal from the factory.
2. The body mounts could be worn/collapsed or loose.
3. Rust in the frame.
4. Prior frame damage
5. Bad spring/spring mounts collapsed.

Guldstrand is a community vendor here and could provide you with the products and support you need to get it straight.

I am also running the complete VB&P suspension. I have not driven the car either, so can't say what I really think of it yet. Redmist here has the full blown suspension on his car and has been driving it. He may be able to give a little more feedback.

One quick easy solution can be to simply adjust the bolt/nut on the rear spring mount. You can shim inbetween to raise it, and losen the nut to lower it.

You might also try jacking the car up on level ground in the front only. Plut the front of the car on jack stands set at equal height under the frame rail (not on the lower control arms). If the car still sags, it will help you narrow it down. Sometimes a tweaked front suspension can make the rear sit different as well.

Good luck, let us know what you discover.

 

[Barry]

Thanks for the replies!
I have been told that the measurements are within factory specs
and that actually having the right rear slightly higher may aid in
traction due to torque loading. Has anyone tried to pre-load
rear suspension to achieve better launches? Has anyone replaced just the rear spring and shocks to match and achieved
a much better ride?Being from Canada parts are at a premium!!!!

Barry

 

[69MyWay]

Barry,

I have never seriously raced a C3. However, I have corrected tilt and sag by shimming up the rear spring. I imagine you could preload, or do whatever you want. Being that it is a IRS, it make make things a little more complicated to get just the right pre-load.