I recently replaced my delaminating front and rear springs with the VBP sport springs and my worn out Bilsteins with Koni yellow adjustables on my '94. At the same time I added a camber brace and replaced all tie rods and upper/lower joints on the A-arms. I also have all poly bushings on the car. Before the swap I could feel every pebble in the road and any bumps would jarr me (I had the base stock springs).

My goal was to get a more pleasant ride with good handling (kind of like an M3 which my brother has ['03 model]). I know I cant get that kind of ride with leaf springs but I'm not making much progress.

The problem I first had was on every large dip in the road the car would catch air and I'd hit my head on top of the roof (not pleasant at all). The ride was better though on just slightly bumpy roads. The Konis were set at zero firmness ( I think they can be turned 2 and 1/2 turns for full firmness.

Then I set the rear shocks to 1 full turn and the fronts to 1 and 1/4 turns. Now I don't hit my head on those dips but I get close, on the other hand the ride is much stiffer and I feel all the bumps in the road again.

At this point I think I need to set the Konis even firmer to avoid the jarring I get when I got over a dip at ~40 mph or faster... but of course the ride will be harsher.

Does anyone have any suggestions on what I can do (besides coil-overs as I've spent alot on this setup alone).

 

I don't know how much smoother you will be able to make the ride as all the components you have added will stiffen the ride signicantly (with exception to the camber brace, tie rod ends, and joints). I'd guess you will have to experiment and find a happy medium.

 

I thought the Sport springs would give a harsher ride than the stock springs I had on but VBP assured me that the ride will be more pleasant while giving better handling (which it did when the Konis were set at zero firmness).

A current post asking about the rubber cushions that go on the ends of the front spring made me wonder if I should take them off the stock spring and add them to the front VBP spring. The VBP spring has a plastic like covering over the ends of the spring so it wont get damaged and had no instructions to add the rubber cushion to it however.

Has anyone noticed a much harsher ride after removing the front spring rubber cushion that sits on top of the lower A-arm?

 

You are experiencing an inherent problem with the C4 suspension: limited travel.
Because the car rides so low, the suspension cannot allow much travel or the car will bottom out and/or the tires will rub the bodywork on jounce. A short-travel suspension demands stiff springs to prevent constantly hitting the bump stops (which really messes up ride and handling!). There is no way to achieve a Cadillac ride with a C4; you have to have stiff springs and lots of damping to control those springs. The result is a harsh ride...it's unavoidable.
Coilovers cannot cure this because they cannot address the main issue; that of very limited suspension travel. In other words, it isn't the type of spring that is a fault, it is the high spring rates that must be run with this type of suspension.
Spring rates that must be high no matter if they are leaf or coil.

Don't throw any more money at this in an attempt to get a smooth ride AND good handling; it just ain't gonna' happen. The laws of physics are against you!

Larry
code5coupe

 

dan, you did hit on the best option. turn up the damping on the Koni until you feel in full control of the car and live with the ride.

 

Softer springs and stiffer swaybars will get you closer to what you want.

A performance spring that is softer? VBP must be smoking crack.


Coilovers with a progressive spring rate can get you a softer feel for small bumps/upsets and still give you spring stiffness when you're manhandling it and use the extra spring travel.

 

you need a 96 FE1 spring on the back, worked miracles for the ride comfort on my 93. The 96 spring is half the thickness of the 93 FE1 spring and the ride is nice

 

What you want is the stock base springs(soft), not the VBP sport springs.

I'm sure you could find someone that wants them and do a swap.

 

I also vote for soft (FE1) springs for best overall performance.

Soft springs and stiff shocks are not only the secret to a good ride, but to good, real-world (read street) handling.

If you only drive on a glass-smooth track, then ultra-stiff springs will be of benefit. Throw in some bumps, such as those found on every street and highway, and your wheels will spend more time in the air than on the ground, which is never a good recipe for handling...

Larry
code5coupe

 

Thanks for the replies, I thought I should have went with softer springs but I trusted VBP knew what they were talking about. I initially asked for an even lower spring rate than what my '94 came with stock but they suggested the sport springs