I searched and searched but couldn't find a similar scenario. On my 996 GT3, I recently stiffened my front swaybar to full stiff. Since then, over sharp bumps that are even on left/right side, I believe that the bar is hitting the topside of the LCA's. Car is corner balanced, not too low, Tarrett adjustable drop links, pre-load was properly set at time of adjustment.

So my question is, is there any adverse effect to setting proper pre-load and then adding a half turn/full turn to the links to allow for enough bar clearance from the LCA? I should mention that pre-load was set with car off the ground, so it's likely that settings would be different if I did it under load. Is that likely the case?

 

This is an interesting question. I hope I am not hijacking your thread, but I have been chasing an elusive "clunk" in my 996 GT3. My car has 28K miles and no track time. Suspension feels firm and tight.

The clunk appears when swerving hard left to right, as you would do in warming up your tires. I replaced the stock sway bar drop links (which weren't bad), and also recently had Elephant Racing rebuild my front struts (which also weren't bad).

After reading this thread, I am wondering if the sway bar is hitting the LCAs and making this "clunk". I don't see any rub marks on mine. Do you see clear evidence of your sway bar hitting your LCAs?

Thanks, and again, sorry if hijack.

JA

 

Adjust the length of each drop link by the same amount and you'll be good to go. It won't change your preload.

 

Good stuff! Thanks, powdrhound

 

No worries about a hijack! Scenario is different from the problem I'm having, but it sounds like it could be swaybar related. In your case, though, my guess is that you'd be contacting something other than the control arms. The clearance should be sufficient between the bar and the arms under the type of load you're describing. If they were too close, I think contact would be more likely in same situations like mine.

I was able to feel a slight kink in the LCA where it was being hit by the bar. Would it be possible for you to inspect the area with turning at full lock, to see if anything looks to close for comfort?

 

Just for posterity, I thought I would post an update to my partial hijack in this thread:

*** UPDATE ***

Does Rennlist have a traveling dunce cap, or "Walk of Shame" forum? If so, kindly direct me there immediately.

I bought this car last year 4th of July. Really have only done some fun runs with it, and not pushed it. Until one day in late winter (February?) I was following my buddy in his '09 C2S, and we were slaloming a bit as you would when "warming the tires" on cold tires/cold pavement. I heard and felt this significant clunk, left and right both sides.

Well, nearly 6 months later, and a lot of chasing my tail....apparently the P.O. had completely removed the battery hold-down clamp!! You can see where this is going! Well, last night, in a fit of desperation, I popped off the trim and tried to move the battery side to side. It moved a full two inches in either direction, banging up against the side of the battery tray on each push/pull.

Tonight, I fabricated a temporary metal bracket, bolted it down, and almost spun the car trying to re-create the clunk. Silent.

So, I am a monkey. I only post this to close the loop on what has been a frustrating journey for me, in the hopes that the next guy who is chasing something that he is sure is one thing, checks ALL the easy things first!

Thanks to Rennlist for the outstanding support and guidance, as always. I'll be over here in the corner with the pointy hat on!

JA

 

BTW Mike, you should probably adjust the drop links with the wheels on the ground, as the car sits, since that is the position in which you want no preload. It should be close to what you get with the car in the air since you 'should' have similar droop in both dampers.

Anyway, just my opinion, so I could be wrong.

 

Yes, this I know! My problem is that I don't have the right equipment/facility to do it correctly.

Suspension's actually half apart this weekend, I'm putting in upgraded LCA's up front with monoballs and caster pucks. Going to switch the front bar to position 2 (1 from full stiff) while I'm in there and add a bit more negative camber to compensate. This all means I'll need an alignment so I'll get it all properly set up at that time.

Francois, your setup is full stiff up front, correct? Would it be easy for you to measure the length of your links? My feeling is I need to make them way too short to give the bar enough clearance from the arms, and it's not sitting right with me.

 

Yes, full stiff. Drop link is 7 1/4", and bar is 2" above LCA. But all this depends on what the drop link is anchored to at the top.

 

Nice pic, Francois. Are those the PMNA/Cup drop links?

Also, anybody have the torque spec handy for the strut housing "clamp" bolt? Or maybe a complete torque spec list somewhere?

Thanks,

JA

 

No, I don't think that they are Cup drop links. They were on the car when I got it.

This could be the torque that you are looking for.

 

Mike, you should post a picture also; this doesn't sound right.