I have an '02 C4S and I attended a track day last weekend. During one of my runs I got my car loose and to get out of it applied some opposite lock and jumped on the throttle. At which point a somewhat nasty groan/harmonic came from the drive train during the slide. The motor didn't bog or rev, I felt nothing in the steering wheel and ran two more laps that session without feeling anything different.

I ran the car for another session as well and drove it home without feeling anything different. I believe I had the PSM off, but I forgot to check after the run.

Any ideas on what it could be. The clutch as 30K on it and is a bit soft.

...Joel

 

Shot in the dark, have you replaced your motor mounts ever?

They are filled with fluid and mine leaked and had to be replaced after I jacked the car once. Went with GT3RS solid mounts.

My thought here was the engine may have tilted a little more than designed, but not enough to be permanent.

Again... shot in the dark...

Cheers
Aaron

 

Antilock brakes?

 

I'm thinking it was something to do with the PSM, but I believe I had it off at the time, but I forgot to check when I pulled in.

I didn't think the ABS would be that noisy and it really happened after I jumped on the throttle.

...Joel

 

Regarding the antilock brakes, did you feel anything from the brake pedal. When the antilock brakes engage, it feels like a shudder on the foot and definately a groan. It gould have been the viscous coupling to the front. If the rears are spinning and the front is not, something has to give.
James Greer

 

James,
I was just off the brakes transitioning the car when the car broke loose then stabbed the throttle so I'm not sure if there was any feedback in the brake pedal. My thought was also the viscous coupler, but the groan sounded like it came from the rear of the car and I believe this is up front.

...Joel

 

Just to add to this for future reference on here I talked to a local shop here in Orange County and they attribute it to the LSD in the rear.

...Joel