Rear lifting in hard coenering, Too much spring? Options

[retrotech]

I wasn't ready to deal with the suspension yet, but today I was told my the guy behind me. In hard cornering, instead of being flat, thew rear corner would lift. Thats not good. This was the first fairly hard drive, with some R Gruppe cars.
The PO said they were 400#, I assumed he was mistaken, that didin't seem reasonable. He said he has had a track 914, and that is the set up he was successful with. So what do I need to do. It has front sway bar, don't know what the torsion bar is.
What are the suggestions. I don't care about comfort, I just want an optimal performance for street & track.

1970 w/2.8 2000#


Thanks

[slivel]

QUOTE (retrotech @ May 22 2005, 03:04 PM)

I wasn't ready to deal with the suspension yet, but today I was told my the guy behind me. In hard cornering, instead of being flat, thew rear corner would lift. Thats not good. This was the first fairly hard drive, with some R Gruppe cars. The PO said they were 400#, I assumed he was mistaken, that didin't seem reasonable. He said he has had a track 914, and that is the set up he was successful with. So what do I need to do. It has front sway bar, don't know what the torsion bar is. What are the suggestions. I don't care about comfort, I just want an optimal performance for street & track. 1970 w/2.8 2000# Thanks

In your first post you said, .What are the suggestions. I don't care about comfort, I just want an optimal performance for street & track. I think many will agree that you can't have "optimal" performance in both worlds. Anything you do will be a compromise. Even between tracks you can change spring or torsion bar rates to optimize. If your track experience is minimum, I would recommend the previous posts who suggested staying on the softer side on the rear for now - something 200 or less. If you are lifting a rear wheel on cornering, you are really unbalanced in the extreme. This is a characteristic of a front driver not RWD. There was also some good advice about matching the shock valving to your spring rates - otherwise one is overpowering the other. You can "stiffen" the suspension by just repalcing the shocks with high compression/rebound shocks. Many people do this and it works to a point, but the better solution is a shock that is valved to be complimentary with your spring rates and corner weight.

My point about the motion ratio is that if you have 300 lb/in spring rate in the front and want to match it in the rear, putting 300 lb/in springs won't do it because of the leverage from the moment arm of the rear suspension. You would wind up with 504 lb/in in the rear.