Suspension Feedback

[Okiedoke]

Originally Posted by DRM500RUBYZR-1

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

I think it's the stock height. Here's a picture that I took today:

Originally Posted by DRM500RUBYZR-1

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.

I had the Z checked out by a Corvette shop when I got it 3 years ago. The only issue was a delaminating rear leaf spring, which I replaced right away from a Corvette salvage yard. I don't know the miles on the spring.

Originally Posted by DRM500RUBYZR-1

Next, do the usual bounce test at each corner to see if one or more shocks has too little resistance in either direction.
Marty

So I drove the Z to work today and went over speed bumps at 3 MPH. I don't think I felt the rear bounce. However, the front very noticeably bounced twice.

I have a right front actuator time out code that comes up once in a while, which I assume is an issue in itself, but is unrelated to the bounce?

Thanks,
Harry

[Okiedoke]

Originally Posted by USAFPILOT

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.

1991

[Okiedoke]

Originally Posted by RussMcB

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

I found these on their site: http://www.ajusa.com/1991-Chevrolet-...ers-c38cd.html
Do you know which is the right part number? Are the front and rear the same?

Originally Posted by RussMcB

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

Found DeltaVee's rebuild service: http://deltavee.net/shop/services/bi...table-dampers/
Quite a bit cheaper to rebuild than buy new!

[Okiedoke]

Originally Posted by mike100

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$.

This being a Corvette and ZR-1 at that, I was thinking it couldn't possibly have bounced this much when new. My plan in general is to keep this Z stock but also will be doing more autocross and track days with it. Do you think stock valving/rebound/compression would be sufficient? It must be much better than what I'm experiencing now.

[mike100]

Originally Posted by Okiedoke

... Do you think stock valving/rebound/compression would be sufficient? It must be much better than what I'm experiencing now.

New stock replacements sufficient or adequate? Probably yes.
Could it be better? ...Absolutely.

The LT5 is heavy and I think it wears out the front shocks as there isn't a special part number for it- I think all FX3 shocks were the same for all vettes.

Not sure how hard it is to get a modified shock controller these days, but that is another way to make them stiffer/sooner (at lower speeds). Even so, I liked the amount of rebound control my car has now.

[mike100]

Originally Posted by Okiedoke

This being a Corvette and ZR-1 at that, I was thinking it couldn't possibly have bounced this much when new...

I haven't driven a new one since 1993, but you are right- they didn't wallow and bounce much on the stiff setting.

[DRM500RUBYZR-1]

Your rear spring already had delaminated and has been replaced.
Please make sure you inspect that front spring for the same delamination, or splitting, cracking, whatever you want to call it.

As these fiberglass springs delaminate, they lose their ability to react properly to suspension travel, i.e. they cannot control the movement.

Back went; front may be going too.
Easy to see; It looks like it is shredding.

I remain equally convinced that due to age, you most likely need shocks, certainly front ones based on your description.

Check the spring.
Replace the shocks.
AND check those actuators.

Keep us posted.

Marty

[Okiedoke]

Originally Posted by rkreigh

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.

PM sent.

[Z51JEFF]

Originally Posted by Okiedoke

I found these on their site: http://www.ajusa.com/1991-Chevrolet-...ers-c38cd.html
Do you know which is the right part number? Are the front and rear the same?


Found DeltaVee's rebuild service: http://deltavee.net/shop/services/bi...table-dampers/
Quite a bit cheaper to rebuild than buy new!

AJUSA is where I got a new set. Don't bother with DELTAVEE,guy tried to pull a fast one on me and it cost him a new set of shocks. Too long to get into just won't ever recommend the place.

[RussMcB]

Originally Posted by Okiedoke

I found these on their site: http://www.ajusa.com/1991-Chevrolet-...ers-c38cd.html
Do you know which is the right part number? Are the front and rear the same?

I'm not sure if either of these links work. They're bookmarks from 2 years ago.

http://www.ajusa.com/1991-Chevrolet-...v7c2q6c61.html

http://www.ajusa.com/1991-Chevrolet-...ers-c38cd.html