OK suspension gurus
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Instructor
Joined: Sep 2012
Posts: 222
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From: Yukon OK
OK suspension gurus
I have a 1990 Z51 non FX3 car, and I know the front spring rates are 115 nm, rears 57 nm. Now the spring rates on the front are higher than the 84 Z51 cars, but the rears arn"t 84's were 87.5 nm. Now my question is this would I get better handling with the rear 84 springs or would the car tend to oversteer more?
Safety Car
Joined: Aug 2009
Posts: 3,752
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From: Melbourne, Victoria, Australia
I have a 1990 Z51 non FX3 car, and I know the front spring rates are 115 nm, rears 57 nm. Now the spring rates on the front are higher than the 84 Z51 cars, but the rears arn"t 84's were 87.5 nm. Now my question is this would I get better handling with the rear 84 springs or would the car tend to oversteer more?
Yes the stiff rear springs or tough front roll bar tend to give more oversteer which a C4 doesnt want, they are plenty loose in the rear as is.
The springs should be matched to the shock absorber, the shock absorber needs to control the car.
Wheel offset has a big effect also, i recall my carting days trying to adjust the rear wheels out to get the best of slide and grip. Too much grip and she would easilly roll over, it is a ballancing act and best to pick a spring and roll bar set from a Z51,
the factory Z51 works best, its a tried and proven setup.
That will give you a firm ride better handling and a safe setup for most uses.
If you want a great track car go for double adjustable coilovers and look at the Van Steel website
They are the only way to go.
http://www.vansteel.com/index.cfm?fu...&SubGroup=1972
Last edited by gerardvg; May 8, 2014 at 12:03 AM.
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
I have a 1990 Z51 non FX3 car, and I know the front spring rates are 115 nm, rears 57 nm. Now the spring rates on the front are higher than the 84 Z51 cars, but the rears arn"t 84's were 87.5 nm. Now my question is this would I get better handling with the rear 84 springs or would the car tend to oversteer more?
Max G’s
Joined: Nov 2008
Posts: 2,751
Likes: 79
From: Monroe OH
NCM Sinkhole Donor
You have a very good suspension already. Only thing you need to do is make sure your shocks are good and get an alignment. Try to find someone that actually has experience with alignments on Vette's. On e you get it aligned you should be good for several years unless you run off road or curb a wheel. If you really want to dial in, get some Koni Sports and you can adjust the ride to your taste within the limits of the shocks.
