gr86ss

Has anyone else installed QA1 coilovers?

I installed a set recently and have a clunking noise in the rear. I initially thought that it was the end links (same sound) so I replaced all four. Well, the noise is still there.... I have double checked all of the fasteners and am now wondering is this is inherent with coilovers??

thanks in advance for any advise

keyplyr

Not familiar with QA1 coilovers, but I currently have Phadt adjustable coilovers installed and have no "clunking noise in the rear" so no the issue you're experiencing is not "inherent with [all] coilovers."

Good luck determining what the problem is

Xedes

I read in a post that someone else with the same coilovers needed to notch out a small piece of their outer sway bar for clearence. Could that be the sound your hearing? Check the sway for any marks.

gr86ss

Since I installed the shocks, I have been having a "clunking" sound from the rear of the car. At first I thought that the anti-sway bar end links needed to be replaced, as this was the exact sound I was experiencing when my original end links went bad. I replaced all end links, and the sound still persists. I've gone over all fasteners and confirmed that all are tightened and none are loose.

Last night I noticed that the rear shocks top mount is hitting the adapter mounting plate. Both sides are hitting, but the driver side is more audiable.

Attached is a picture I took last night with the full weight of the car on the shocks. As you can see there is very minimal clearance between the top of the shock mount and the adapter mounting plate. There is evidence of the top of the shock mount hitting the adapter mounting plate. I'm suspecting that there is enough movement in the rubber bushing to flex the shock mount into the adapter plate.

I've sent and email and picture to QA1 to see what their response is.

gr86ss

With the car on a lift there is a bit of interference with the coil springs and swaybar, but with weight on the car, there is sufficient clearance.

gr86ss

I got word back from QA1 that the rear upper shock brackets are the old version. They are sending me a revised version that will pull the top mount of the shock away from the bracket base.

I also ordered some 450 lb springs. The original 450 lb springs that came with the kit were too short in the front (p/n 9-450), so I installed 650 lb springs. The 650's are way too stiff for my daily driving taste.

I ordered a set of 10-450 for the front and 7-450 for the rear. I'll post comments on ride when the brackets and new coil springs come in.

Xedes

gr86ss

Here's pix from when I removed the shock and mount from the rears. You can see how the top of the shocks were hitting the QA1 shock mount.

gr86ss

Here's a pic of the original shock mount that I modified until I could get the QA1 replacements. The one on the right is what QA1 sent me. I guess I could've left the ones that I modified in, but the "NOISE" still presisted...

gr86ss

Look closely at both of the pix below. You will see that the upper shock mount isn't parallel with the mounting bracket ears. It's only a few degrees, but I believe that this is causing the mount bushing to wear pre-maturely and that's why I'm getting the "metal to metal" or "solid bushing" associated noise in the cabin of the Vette.

LEFT shock mounted:




RIGHT shock mounted:

gr86ss

here's pix of the bushing:

Xedes

What is you overall impression of thee QA1's? Would you buy them again or save some cash for another brand?

gr86ss

QA1 has been very responsive and sent out the updated upper shock mounts. Unfortunately, it didn't solve the "NOISE" problem. They have a set of harder durometer bushings for me to try. I hope that these solve my noise issues....

I still firmly believe that because of the difference of angles between the mounting ears and the upper shock mount, that the correct fix is to either weld the ears in at the correct angle, OR use a shock body that has a stud for a upper shock mount like the OEM Vetter rear shocks (or like the fronts shocks).

I suspect that QA1 didn't go this route because potential spring to upper a-arm clearance issues. I'll have to lift up the car to see if this is the case.... Otherwise I'd recommend that they go with an upper stud mount for the rears of our cars as this would solve the compound angles that are involved with the factory mounting position and the angle at which the shock is at when attached to upper mount.

VETFEVER

Wow gr86ss, here you are doing field observations and engineering of the product.

I can see that by creating/enlarging the opening in the mount how you eliminated the clunk noise, but that non-parallel operation looks worrisome.

Any more feedback on how they plan to fix this - I guess one could "shim" the base of the mount to give it the proper angle so it is parallel to the shock??

You were posting your post #13 as I was typing...

Keep us up to date - I am considering these as a winter purchase...

vetfever

gr86ss

Overall, I'm happy with the quality and ride of them. My car was originally an F55 equipped Vette. I installed simulators and these QA1 shocks. I have them set just a little harsher than the touring setting of the F55s, if I go softer the rear pogo's and bottoms out. Reason that I changed to coilovers is cost, and handling. My car didn't handle quite as well because the factory shock were compressed and were not giving any dampening. With the QA1's it handles 100% better.

So far QA1 has been doing their best to solve my issues, so I'm happy with their customer support team.

I asked them if they had any other customers telling them what I've been telling them, or am I an isolated case. I didn't get a straight answer...

I'll keep everyone updated as things progress...

VETFEVER

Thanks for your sharing of info with this....

gr86ss

LOL.. Yeah, I told QA1 I'm not a suspension expert, but I am a Mechanical Engineer and even if I wasn't, the shock angle issue is pretty obvious in my eyes...

gr86ss

One other thing...

If you order for a compliant ride (READ: SOFT OLD MAN RIDE), make sure you get 10-450 shocks for the front and 7-450 for the rears. My original order came with 9-450 for the fronts (9" coil spring with 450/lb spring rate) and I had them set at the highest coilover setting and still couldn't get the jack out from under the car.

With these springs I was able to get a very close ride comfort as the F55 suspension shocks/springs.

I tried the 650 springs and those are totally NOT daily driver friendly..

gr86ss

Looking closer at the pictures, the angles between right and left sides are VERY close, although mirror image of course. A shim correcting the angle would solve the problem.

I've given QA1 tech support a link to this thread.

blackmagic9805

I had a slight noise issue with the original brackets on my C5 as well but QA1 exchanged the upper bracket for the new one with the hole in it that prevents the shock body end loop from making contact. No more clunk.

Looking at the pictures of the shock installed in the brackets it almost appears the brackets were reversed left to right. Mine had an "L" marked on the left side bracket and an "R" on the right. The brackets look very similar but they can not be switched. My shocks are straight in the brackets with the weight on the wheels. As far as the spring rates go I have 450s on the front and 550s on the rear. I love the way it handles with that set up. Good luck.