Suspension Feedback
 

My suspension feels quite bouncy/floaty, almost like a boat rolling over the waves. This is very obvious on Tour mode to the point I'm not comfortable driving through mountain highways. On Perf mode, the ride is pretty harsh as expected but I can still feel some of the bouncing/floating. Since this is the only ZR-1 I've driven, I don't have any point of comparison or know what it would have felt like when new. Any ideas on whether this is normal or what parts I may need to replace or rebuild?

Thanks,
Harry

Re: Suspension Feedback
 

Mileage?

Re: Suspension Feedback
 

Just passed 27k miles.

Re: Suspension Feedback
 

OK, That is odd.
It should not feel that "floaty" with those miles.
Does the ride height appear normal?

Logically, shocks or springs.
Get car in the air, and check both front and rear springs for any splitting or cracking of the spring itself. Typically, the car droops noticeably if there is an issue with the spring.
Next, do the usual bounce test at each corner to see if one or more shocks has too little resistance in either direction.
Check the condition of all of the suspension bushings, front and rear.
Alignment, if all of the other check out, then check the alignment of particularly the rear wheels and the camber settings. If too positive, the car can seem twitchy, which sometimes is described as unstable. Refer to Vette Brakes and Products for their suggested street settings as a good reference.

My first suspect would be the shocks might need replacement, although the mileage seems low for that.
Most often, that causes the sea sickness symptoms.
Let us know what you find.
:cheers:
Marty

Re: Suspension Feedback
 

It is the stock valving on the shocks. I got my car with exactly the same mileage (27k) and i felt the rebound was 'loose' or bouncy. Compression was ok, but could have been stiffer too. I ended up sending (dropping them off at their shop in person) my shocks to Bilstein to get slightly more aggressive valving, but not race valving or anything like that.

I ended up with the request to increase rebound 20% and compression 10% if I recall correctly. I didn't alter compression much because it would be possible to program the shock controller to stiffen the setting at a lower speed...it was the floaty rebound that needed the correction. If you search my name here and 'bilstein' the post should come up.

I hear they aren't keen on rebuilding these shocks anymore, but might custom valve brand new unit$.

Re: Suspension Feedback
 

Sounds like a shocks/dampening issue. I can't think of a reason why springs would cause this behavior.

I was fortunate to find new Bilsteins for a decent price at "AJ USA" I believe (or some name like that).

You can also search for "DeltaVee". They offer rebuilding services for our FX3 shocks.

I've very happy with how my car handles, and it's mostly stock, 67.000 miles, good alignment. I can definitely feel a difference with the three settings.

Re: Suspension Feedback
 

If the spring is failing due to splitting, the shocks are unable to properly or adequately compensate for it's failure with the added burden it places on the shocks during suspension travel.

Shocks remain the most likely culprit, but it is essential to check all of the components while there.
Let us know what you find.
:cheers:
Marty

Re: Suspension Feedback
 

what year? The later cars softened up the spring rates and the shocks are now dried up and likely not dampening as well as they should.

do the "bounce test" and push down and the front of the car and see how the shocks feel. They should dampen out right away and not allow you to feel a bounce or softness.


The later cars can feel a bit "boaty" and skip around over bumps. I went to the coil overs and while they can be a huge pain, they do give the car that planed feel I was looking for.

I really like the banski rods for the back. they take all the "sticktion" out of the suspension travel and free it up without being harsh.

Let me know if you need FX3 ZR-1 shocks, I have some 90-92 for sale.

you can also use them on later model ZR-1 with the right controller box which I also have. PM me if you need anything.

Re: Suspension Feedback
 

In my opinion, at this point in the car's life the mileage doesn't matter. You can't avoid the fact that they are now 20+ years old. I replaced my shocks for close to the same price as it was to rebuild (back when they rebuilt them). I paid $800 including shipping for 4 new ones. Now it rides great.

Re: Suspension Feedback
 

what year model? I think I read that the C4 springs were softened every year, and that switching to a 1990 spring with the later C4 shocks would ride better, or more sporty, less float.