Clunk sound sometimes when either first accelerating or braking...strange

[DarthChicken]

I get the same thing... to me, it sounds and feels like the brake pads sticking to the rotors after you wash your car.  Or maybe the e-brake pads clunking.  Its definitely something you can feel more than you can hear.

[maverick1]

Glad to know I have some company on this matter. It doesn't happen all the time just intermittently.
cheers

[silver]

Try this......pull up to a stop sign....push the clutch in....move the gear into first...THUNK..at least that's thunk #1, there are actually several thunks that occur on my car.  just want to see how many occur on y'alls

[MadMaxedAtom]

Turn up the radio....

[rfmarz@frontiernet]

My noise has nothing to do with the brakes as it was after a high G left turn on 2nd gear out of turn 2 at Hallett. Could it be a side shift in the axle  which gets corrected with application of full throttle?

[rfmarz@frontiernet]

I'd just love to think that the noise is something as innocuous as a shifting brake pad, but sometimes it is so loud and creates a significant vibration. I guess I can just hope that it is. Spanky, which brake package did you install? I have the Wilwood (track package).

[silver]

Just to chime in with this...I have the track package, and my thunking occurred in the warmer weather....I haven't driven the car in colder weather

[MadMaxedAtom]

^ you have cold weather?

[silver]

yeah, anything under 70 is cold.....it's 41 today 

[positron]

[quote="rfmarz"]
My noise has nothing to do with the brakes as it was after a high G left turn on 2nd gear out of turn 2 at Hallett. Could it be a side shift in the axle  which gets corrected with application of full throttle?
[/quote]

Mine too, I'm checking to see why I only have about an inch travel on rear shocks. It appears that they have been bottoming out against yellow stopper. Am watching front door step for corner scales that Santa ordered to try my hand at leveling the car and suspension adjustment.

[dingo]

All pros, no cons and for the reason(s) you've declared.
Measure the distance from the shock body end to the adjuster seat as it is now.

Remove springs and reinstall in reverse, but as you are about it, screw the retainer further up the damper body than where it has been. 

If you've only got one inch of compression, then you have a great chance of bottoming out the damper compressing the polyurethane bump stop.
 
If it were my shocks, I'd screw that seat half an inch tighter.
The result will be a slightly higher ride height but more available compression.
You can reduce any extra ride height that by shortening the push rods by two full turns on both sides. 

[positron]

[quote="Spanky"]
it places the connector that is between the helper spring and the main spring to be just behond the shock body. What this does is that when the spring starts to compress, the inside of the connector strikes the corner of the shock body making noise. I took the shock springs off and found that the alum. connector had a lot of metal worn away. And the threads near that end of the shock has a lot of black anodizing worn away from the top of the threads.  So I consulted a Koni racing retailer and their tech help said I should swap my springs end for end. This would place the connector well down on the threaded body so it will never travel off & on the end of the body. I am sure someone has already tried this. Any pros & cons?

[/quote]

Can this been seen while assembled and did the wear have any orientation? ie tops/bottoms. I'm not seeing any signs of this on mine but not sure if I'm seeing correctly.

[positron]

I see what your talking about now. Mine is rubbing the threads outboard, both sides but on the driver's side the spring is biased closer to the top of the threaded barrel. It appears that the spring is bowing instead of compressing linearly. It also appears that it has been rubbing the intake tube more regularly than I had thought. I thought that I had just had the tube too close but it appears  that the springs bow quite regularly.

I'm not understanding how reversing the springs will help the bowing, seems the middle has the most defection potential no matter it's orientation. Maybe only what it hits? May need UHMW bushings to maintain parallel interference with tube.. Is that possible with the arc of the bellcrank?

Krap.. more money for upgraded springs...

[DarthChicken]

I'm betting its the bellcrank geometry.  Its twisting things just enough out of alignment while the suspension is partially compressed, so the springs can't twist with it.

[positron]

Found this interesting.. search for Why springs bow. http://www.stockcarproducts.com/spgtech.htm

"spring rate will increase if active coil rubs another part of the race car."

I'm assuming the rate increases while it's bound to shock barrel and then when it let's go causes the car to shift. I found that shift/side step disturbing mid corner in the corkscrew..