I have a 94 Coupe, 17,000 miles. Prior to getting sidetracked by replacing the water pump, I was concerned with the car "skipping" over rough bumps in the road. I just don't feel confident at 85 mph when I hit that rough road and the car seems to skid over the bumps. My allignment has been checked and the shocks seem to be ok (but are the original bilsteins). Some of you have suggested I change the shocks to Koni Sport Adjustables (yellow). Will it truly make a difference or am I experiencing normal C4 hard suspension over bumps? New shocks would be a big investment. Thanks for your feedback.
DrRich

 

I installed just those shocks on my 92. They are really nice.

They won't cure all of the problem (I blame it on the nature of the transverse leaf spring, flame suit on), but they sure do help slow it down. I have mine on uber-soft. the LA freeways are NOT the smoothest things on earth.

What PSI are your tires set at? Over inflation will make this worse. Bring them down to between 30~35 PSI and see what happens.

 

I went from FE1 (base) Bilstein shocks to Z51 Bilsteins on my 96, and the difference was absolutely *UN*believeable. It's been a few months now since I made the swap, and I can't remember how it used to ride. All I know is, it now rides like a Corvette SHOULD...and when I think about the old ride, the word "Buick" comes to mind...

 

that's going the wrong way.

overly stiff suspension is what causes the problem Dr Rich has, not overly soft.

 

I re-read your orig. post/thread. If everything's correct, and if your suspension is fine, alignment is fine, and shocks seem to be ok, I can't see where new shocks on a 17K mile car will help. It will "change" the feel of your car, but not help that feeling you get at 85 mph over rough roads!!

Now that you have the right pressure in the tires, maybe the only thing you can try is new shocks. I doubt if the mechanic has it wrong that there is something wrong with them, but it's remotely possible. However, as you state, this isn't a cheap experiment.

Just make sure the tire pressures are taken at stone cold, early morning before you drive, and are at that 30-35 range all around. Is it possible you have the Z51 suspension? Check under your console lid and see if one of the "codes" is Z51.

Only other thing I can think of is, are you a member of a club? See if you can ride with/drive someone else's '94 with similar suspension. Or put out a query here on CF General that you want a ride to ck your suspension against theirs. Worth a shot.

 

I'm going to catch a ride with other C4s over the next few weeks and compare my ride. My car handles tremendously, is very strong, drives straight as an arrow, but just seems overly stiff. Maybe that's the way it's supposed to ride. Let me know if you have changed your shocks to Koni Adjustable and if it helped to hold the road better when driving over those rough spots in the road. I like to let the car ripp when I get the opportunity, but those rough spots are alittle shakey.
DrRich

 

I just went ahead and made a mtn run yesterday after work to try mine out, they aren't supposed to be broken in yet but what the heck. Seems to have made a big difference in the ride. It does seem to show bumps in the road a little more, however, it also seems to have cured the skating problem. The ride before was ROUGH because the shocks were too soft up front and too hard out back. Now they are harder all the way around and that means the bounces are absorbed like they outta be instead of in my back. I like it a lot better now. Still have to hit the hwy and drag strip, but the high speed mtn run was the real test for the skating problem.

You might be better off just getting Z51 shocks like a few other members vouched for, but it sounds like almost any shock is better than stock no matter the miles on the car. The national champion here in town recommended koni to me, that's why I got them.

 

I had the same problem/concerns when I first got my '86. When cornering, it seemed to "hop" in the back if I hit any bump at all. I replaced the original shocks with KYB and never had that problem again.

 

I think a lot of this is "built in" to the car. The primary function of the shock is to slow/limit rebound, and dampen, as I understand it. Just reading the different responses it seems like some want a "soft" ride and some expect it to ride like a sports car. I guess that is why Bilstein offers 3 versions for our car. I like my Z51 and wouldn't change it.
www.shockwarehouse.com

 

It's time for chassis philosophy 101:

A stiff suspensions sounds all romantic, and the expected norm for a sports car, but it isn't the panacia people want it to be.

The hopping that people are getting mid corner is BAD. Very bad. It means the tire has lost contact with the pavement, which translates directly into the driver having lost temporary control of the vehicle.

Hopping is caused by an over stiff and poorly damped suspension. It means that the tire has left the pavement, and the shock can't react fast enough to absorb the impact that caused it in the first place.

A softer shock will improve this. A nice coil spring will damn near cure it.

For comparison, Sebring International Raceway is noted for being very rough and abusive to both cars and drivers. 12 hours there is like 24 hours everywhere else. Now, everyone is wondering, why does Audi and Corvette so own that place? They have a simular concept for suspension... a soft spring, a firmish shock and stiff roll bars.

What good is a tire if it can't stay connected? and, what good is a drive that has to constantly correct for it.

I have noticed a lot of Forum members expressing near sexual pleasure at the 1984 Z51 setup, because it is so stiff and steers so quickly. Sure, that's great... until you hit that bump mid corner... and the entire *** end steps out 6", causing the car to be come unsettled.

That Z51 is great for smooth roads, but short of Daytona, they don't exist.

Then comes the Transverse Leaf Spring... great for packaging, but I am not convinced it's the best spring material or concept on earth. If it was so great, why doesn't Ferrari or Porsche use it? In all fairness, if rear engines were so great, why doesn't anyone else use it?

With that said, I have read several reviews of the new Z06, and it has a tendency to step out, too. Same with the regular C6. The common thread? TRANSVERSE LEAF SPRINGS.

I have never heard of this kinda mid-corner problem with people who have converted to coil overs.