Just back from vacation, I would like your feedback one more time before replacing the original bilsteins on my 1994 with 18,000 miles. At 60 mph and higher, when I drive over a series of bumps (rough road) my wheels skip and lose traction (it's a bit freaky). Tires are at 30 psi, allignment is solid. I do not see leaking on the shocks and they are pretty stiff. The suspension is very tight and stiff (drives great on smooth surfaces, but gives a very stiff skipping over a series of rough spots). Will I improve this situation by replacing the shocks, or is this status quo for the C4? If new shocks will help, do you suggest replacing with new bilsteins, KYB, or Kuni adjustable? Thanks for your feedback.
DrRich

 

Mine do something similar, have worn out Bilsteins. Ill be getting them revalved soon. Should help your problem.

 

I don't recall from your earlier posts on this issue, but if you have the base FE1 suspension, you might try the Bilsteins for the Z51 package. They are P/N B46-2057 for the fronts and P/N B46-2058 for the rears.

You can get this set from Vette Brakes & Parts for $269.96 + shipping (~$25). You have to tell them that you're a Forum member to get the discount (regular price is $299).

www.vbandp.com

I hope this does it for you!

Steven

 

i tend to think this is more because of the fiberglass transvers leaf spring than anything else.. I had/have the same problem and have already installed new bilstien shocks to replace the old ones.. I've heard coilovers solve this issue.. but I cant confirm that..

 

The C4 is very stiffly sprung, and doesn't not take kindly to sharp bumps, especially in the middle of a turn. Low profile tires exacerbate the problem. You have to accept a certain amount of this as "just going with the territory."

But, you report the problem is with a "series" of bumps.
That sounds somewhat familiar....

When I first got my C4, I had a problem with the shocks giving up control in the front when going over a series of 'stutter-bumps'. The 60K mile Bilsteins weren't doing the job, and new Edelbrocks performed exactly like the old Bilsteins.
A set of new Koni Adjustable Sports solved the problem.

Larry
code5coupe

 

Mea culpa!!!

The correct P/N's for a 1994 Vette are B46-1177 and B46-1178 for the Sport shocks.

I also want to clarify something. The Z51 suspension was dropped between 1991 and 1995. The optional suspension for those years was the FX3 by itself or the FX3 in conjunction with the Z07 package.

However, if you examine Bilstein's application information, you notice that the base shock is HD, and the Z51 shock is SP (Sport). I've read on this Forum of many members that sub the Z51 shock in their base suspension, and obtain better handling with very little sacrifice in ride comfort. These results have led me to conclude that I'll also obtain better handling in my '95 by using the Sport shock instead of the Heavy Duty shock. Thus, my recommendation to Dr. Rich.

A Sport shock is listed for all the years that Z51 wasn't offered, so you can still get the Z51 improvements for your base suspension Vette even though the Z51 wasn't offered.

http://www.bilstein.com/302passengercars.pdf

I hope I have cleared this up a bit, and not made it more confusing (because I can see where it would be).

Steven

 

I don't know if the new shocks will help at all, per rocco's review of "what is a Corvette." At the very least, you will have a new "baseline" from which to tell if this WAS your problem.

Frankly, I recall you had very high tire pressures. I don't recall what tires you have then/now, but that can sometimes exacerbate skipping around on what I'd term "washboard-type" bumps in a curve. So, for now, let's say the tires are static and aren't contributing to the issue you raise.

My suggestion would be: Bilstein stock (FE1) for your car, Z51 Bilstein and Konis, in that order. I think the "harder" shocks will give you more control but most likely degrade the ride quality some. How much from what you've got now, I don't know. And unless you want to go through a trial-and-error process and buy two or more sets of different shocks, you won't know either.

Suffice to say, even if a shock "looks" like it's ok AND has very low miles, it could still not be performing up to par. It's unusual in your case, but it could be happening.

I'd say, make your choice: buy the shocks, try it out, if it's no better, you still have some choices. None of them are great, tho. Live with it, sell the car, curse it every time you go out, buy another set of shocks. Except this one,

pretend you really have a very sophisticated and tenaciously-handling sports car with brand new shocks and which compromises your ride comfort to give you the superlative handling of cars costing two, three or more times as much. Which is what you've got.

Tell us how it all turns out ... ok?