I just installed new Bilstein HD shocks on my 1982 Collectors Edition. The front is great but the back bounces 2 to 2.5 times when I push up and down on the rear. Their is no bounce in the front. Has anyone experienced defective Bilsteins or is the normal? I expected the back to be like the front.

 

I also have the HD's on my 82, don't worry about the bounce, just take it out and drive it. If your shocks are defective, you will know it. IMO you need some movement in the shocks when in a stationary position, as if there isn't any movement, you will really have a very, very stiff ride. BTW, there is movement in mine and they are just fine....

 

I've been doing a lot of research on the Bilstiens. one of the things i've read is with the fiberglass rear spring cars, it's better to use HDs in the front, and sports in the rear to prevent bouncing

 

ok, will offer another opinion on your statement....
I had the Sports all the way around on my 82, and they simply rode to hard for a "dd" IMO. So I sold them and replaced them with the HD's as you know. In fact if I remember correctly you did the research on the rebound rates for both types.
Now I also have the FE7 on the 82, and the rear spring is replaced with a VBP 340 lb spring, which I had special made for the 74 and ended using on the 82...
I do not experience any bouncing what-so-ever, except if you go over a deep dip on the highway, it will bounce up because of the dip and that is it. I think with the VBP springs at a lower rate, (300, 330) you will experience some type of bounce not matter what you use, (330 less bounce than the 300 IMO) unless you follow the manufacture's recommended shocks for that particular spring. Now different springs from different manufactures may produce different results. I have only used VBP springs on the C3s' that I have owned.
I know we all try to get the optimum ride with the correct springs and shocks, unfortunately it is a trail & error situation, as our riding taste may differ from one another....
I am satisfied with the combo I have now, and I suggest again that the OP just drive his 82 on the road to see if he is satisfied with the ride before he changes anything because of the bounce in a stationary position................................ .......................Tom

 

I sure how thats not the case. Im almost ready to install my new #330 VPB spring and HDs all around

 

I have composite springs in the front and rear with Bilstein Sport shocks and have no bouncing. From what I've heard from others over the years, I would only suggest the HD's with the steel springs, and Sport's with the steel or composite springs. Or go with an adjustable shock like QA1's or Koni's.

 

So many different answers, this is why I haven't committed to anything yet. LOL

 

I have a 330# composite spring in the rear with Bilstein Sports and no problem (on a '78).

 

What does the supplier of your spring suggest?

 

BTW when I was making my decision I spoke with VBP, told them I wanted the #330 spring so that its not too stiff on the terrible NJ roads, they said HDs all around will give me a nice ride.... we shall see

 

Stock spring, so GM prob recommends ACDelco

 

I have a 330 with the SP and no bounce.

 

The factory composite springs are much lower spring rate than the ones offered in the aftermarket. The common recommendation of KYB GR-2 (specially valved) or Bilstein Sports is meant for the aftermarket springs.

In 81/82, if you got the high rate spring it came in a steel variant.

 

Front might be harder to get to bounce because of engine weight...rear less so....

 

I had high hopes that the bounce wouldn't show itself during normal driving but no luck. It was like driving an old Buick. No problems in the front but the rear floated up and down. The compression rate on the front shocks was so high that I had to put most of my weight on the shock to compress it. The rear shocks could be compressed much more easily. I'm not sure on rebound; they seemed to return about the same. Someone mentioned installing Bilstein Sports on the rear. Do you find the Sports to be much stiffer? I still have the stock spring.

 

I had Bilstein HDs and a 360# spring for maybe a week. The car was scary when it hit bumps. The Sports fixed that and made the ride quite nice. It is not as nice as a base spring car, mind you, but good for a near FE7 setup.

 

Its possible they might need a little driving time to get the air bubbles and oil where it needs to be.
With that said I went with Koni adjustable rebound shocks! Smooth ride and absolutely no bounce because the push down easy but come up slow so you can't get any momentum for the car to bounce. I have the same car as you but a standard 82 not a CE

 

Unless I missed something in the above posts, I am still not sure what spring you have-base composite or steel for the FE7. Either way the spring rates for the rear spring whether Gymkhana or not were pathetically soft-really soft-like 177 LBS for the base and like 192 for the "sport" with the steel 7 leaf spring in 1982. I am guessing that you have the base 177 lbs/inch composite which is as close as you can come to a marshmallow for any car and yes, much like a cadillac/buick ride mentioned above. With all that said, I can tell you that you are asking the shock-Bilstein in this case-to provide all the damping since the spring is not doing much in that department. My personal opinion after 30 years owning my 78 is you need at least a 300 lb spring if you have a base suspension and 360 lbs composite if it is a FE7. The Bilstein Sport is 30% stiffer than the HD shock.

Without going into all the details on my 78's suspension which was an original sported suspended car, I had the Bilstein HD's with a 360 lbs composite spring and felt that it bounced too much-but nothing like some comments above. Switched to rear sports only (HD's with 550 front coils) and the car drives REALLY nice-not harsh but firm with a VERY comfortable ride. I am often perplexed by those that went with a 330 or 300 LBS composite since I have a 360 composite combo that handles great and rides great as well. So much so that IF i ever need to change my 360 composite (been on the car since 1986), I would consider a 420 spring.

Hope that helps!

 

Curious why you would recommend that, the base suspension has an appropriately low spring rate to much the low spring rate of the front springs (~300#, or less).

I would leave both springs alone or replace them to near FE7 spec.

 

Correct! You would need to upgrade the front as well. My friend's 82 with the base suspension seems to float all over the road when driven at speed. He also complains of frequent bottoming of the rear suspension (hitting the bump stops for lack of a better term) over moderate bumps at moderate speeds. My opinion, not gospel!

Much of the aftermarket recommends 300 lbs rear composite springs with 460 front springs for the base suspension cars and 360 rear springs with 550 front springs for the gymkhana suspended cars, in general.