In your opinion what is the best suspension mod for a C4 (I have a '91 but don't know that the year makes a difference). I have heard a lot about a camber brace and larger roll bars and different shocks. I am not going to spend $1000 for coil over susupension so what would you recommend.

 

The best thing you can do is replace everything to stock. Or add in the parts that make it equivalent to the Z51 handling package. Our cars handle **very** well when the suspension is all new. GM did a good job there. Only problem is it goes from being new to beaten quickly with hard use.

 

So what is the difference in the regular suspension setup and the Z51? I want something that will be just as good as a C5 or is that no possible on a low $ budget?

 

I did some inexpensive handling mods on my Vette:

30mm front swaybar, 26mm rar sway bars poly bushings and endlinks, ~$260.

Poly carrier bushings and spindal rod bushings. Cost was ~$80, but I purchased the whole ES poly bushing kit (everything but the swaybar bushings, cost $175 from Summit/Jegs).

R-D camber brace, $160.

All of these mods really tightened up my Vette's handling. I did all the labor myself, so the cost was low. I'd start with the swaybars and use poly bushings. It's an easy mod to do on jackstands and the improvement is quite impressive.

Eric

 

32mm sway bar front, 26mm sway bar rear
New bilstein shocks, new springs (they do wear out),
new polyurethane bushings is prolly the best MOD you can do

 

if you are really serious about handling, check out the suspension kits on doug rippie motorsports site http://www.dougrippie.com they have some nice C4 stuff :cool:

 

I figured different sway bars would be a good idea. My car is over 10 years old but only has 57,500 mi. on it so I don't know if my shocks are getting old or not? How long do they retain near peak performance?

 

your shocks and springs have been holding your car up for 10 years, but as for driving, i think shocks start downhill at 30k and should be well worn by 75k

 

Here are my suspension mods since I bought the car this past September....

Camber brace $160- $180- tightened up the front on my convertible
Beam plates $145-tightened up the rear of my convertible
Bilsteins 4 @ 279- tightened up all the corners.

I am now moving on to other areas of performance because I am satisfied with the choices I have made to my suspension/chasis :cheers:

 

there's a shootout auto-x at gulf greyhound park this sunday, about an hour south of you. why don't you come out and ask some questions there. plenty of modded vettes...

 

http://vette.ohioracing.com
Check this out. Best suspension modifying guy I have seen yet.

 

The biggest flaw in the C4 is structural rigidity a camber brace and cross bar would greatly stiffen the car as well as reduce rattles. I like my Konis, the stiffer shocks took most of the push out of my car. I would recommend the Koni or Hal shocks. New Konis were rumored to come out the can be adjusted on the car. My rear Konis have to be dropped to adjust as the adjustment screw is at the top of the shock.

 

Just did the rear on my car a couple months ago. All solid metal bushings(racing). Got to say it tighten up everything in the rear. But I spent some $$$ on it. :D Waiting to put in my camber brace and 8-point roll bar.


[Modified by Coupe89, 10:38 AM 5/17/2002]

 

check to see if there is leakage from the shocks, if so definetly replace, but with 57k what do you want? replace them anyways! :cheers:

 

What type of racing do you intend to do?
You plan on just carving corners on the street?
No ones ask that question yet I see.
Setting up a vette for autox, street driving or road course is slightly different.
Also depends on the person. Some are completely happy having a daily driver with full blown race suspension. You'll feel every little stone or rut in the road but will be able to cut a corner like nobodies business.
First off, don't change out the springs for now. The 1991 has stiffer springs than the later models except the Z07 option. I had a 1991 and now have a 1996. Both have base FE1 suspension. With equals miles the 1991 was much stiffer and handled better at Autox events than my 1996 LT4 CE. Tires count for allot in handling. Get yourself some sticky street tires or Kumhos Victor Racers for events. Experiment with the tire pressures. You can change the way the car under or over steers with decreases or increases the tire pressures. You' be surprise what a difference three pounds makes when running at the limit.
Change the sway bars out for something better. Try a 30mm or 32mm front and 26 mm rear. The 32mm is really stiff. You may not like it for the street.
Change out the shocks for Koni's or have the Bilstiens revolved by Bilstien.
Get yourself a decent autox/street alignment. Just with these mods, it will feel like a totally different car. Then go from there with Poly bushings, lowering, and all the other doohickey’s if you feel like you more stiffness.

:cheers:

 

I am just looking to tighten it up for the street. I have only been out to the track once but would like to go out some this summer. I would really like less body roll in the streets turns and corners.

 

That's what I was looking for too. The 30mm/26mm swaybar upgrade is a great start. Much less body sway with very little increase in ride harshness. Cost is less than $300 and it take a couple of hours to do.

Eric

 

http://vettenet.org/susp_chart.html
This is a chart of all the C4 suspension specs for each year and type of suspension. Maybe it will help you with figuring out what will do what.
Also, don't forget your tires. I have a completely stock 10 year old suspension and with my Pilots I outhandled a C5 with stock tires. (He flew off the road and totalled going slower than I was. :yesnod: :sad:

Moral of the story, tires matter and Goodyears are not so good.

 

I keep hearing a lot about bilstein revalving shocks but cannot find anything about this on their website. Does anyone have contact information for this servcie or a shop that can do this?

Thanks

Jason

 

i have a set of bairly used z51 89-96 bilstein shocks i'd love to sell someone, maybe 5k miles on them. they were used and replaced with koni yellows, the 500 i spent on the konis was by far my biggest improvment, also lowering the car and doing a good alignment will do wonders, around 1deg neg camber front and 3/4 rear is a pretty good street combo.