Shift9303

Hey all, just wanted opinions on my car's symptoms before jumping in to a full clutch job.

Just did a double header HPDE event with NASA. I was in HPDE1 so wasn't going too hard but did get some decent speed on my last two heats. On the last heat my clutch began acting up during the end. I had done a quick 4-3-2 down shift into an uphill hair pin. As I was accelerating up the hill and shifting up to 3 I think I began experiencing symptoms of clutch slip. The RPMs would rise however speed stayed the same. I popped the clutch and then released it again and the car began accelerating normally. After pulling off into the paddock drivability seemed intact and on my way home I tried putting my car in high gear and gassing it and did not experience any further slip symptoms. My clutch has roughly 40k miles on it. I autocross and track the car so I am guilty of some hard launches.

Is this clutch slip or something else? Is this the beginning of clutch slip and it only acts up with hard driving? Did I "overheat" or glaze the clutch? Is there a problem with my clutch fluid? I have another NASA event planned at the end of August and because of my personal schedule it might be hard to get in with a shop for a clutch job in that time (in addition to cost).

windhund116

Is this an OEM clutch disc or an aftermarket one?

Shift9303

All oem at this time.

Slowcrash_101

You need to use VTEC in a high gear to know if it's slipping.

Shift9303

So it's a little hard for me to test given space and cops but I've just done several hard pulls and shifts on high way on-ramps and clover leaf cross overs shifting from 1 through 3 at red line and no slipping or rev hang. Also no apparent slipping while accelerating through VTEC transition all the way through 4th gear. Did the same from VTEC transition up to 95 mph in 5th and no problems either. Didn't try 6th because of speeds. I am also still able to slip my car into a roll from a stop in first gear.

WallaceS2K

You've probably slipped the clutch a little on your down shifts and overheated it then, causing it to slip when shifting up out the hairpin... sounds exactly like this (skip to 11.30)
Be careful on your down shifts and you should be able to drive around it for now.

starchland

Verify clutch pedal adjustment before condemning bad clutch

B serious

Is your car an AP2?

I found that after about 10-15 mins of banging shifts at a track, the constant CDV action caused clutch slip.

Once I let the clutch cool, everything was fine.

You could also just be experiencing lifting a wheel. A helical LSD turns into an open diff if one wheel loses enough traction. It works on the principle of a delta torque multiplication. Multiplication of 0 and any other number yields zero.

windhund116

I've heard of the rivets holding the friction material expanding when they are overheated. It causes momentary slippage, which goes away when they cool off and return to normal size. Especially in worn clutch discs.

Shift9303

My car is an AP1 so no clutch delay valve. I just checked my clutch pedal play and it did have some room to cinch up but not terrible. I noticed my clutch fluid was at the minimum line but running low would cause the opposite right? It wouldn't allow the clutch to fully disengage? Maybe it would cause premature wear but I've never had problems disengaging my clutch to get my car in gear. One of my buddies floated around the idea that maybe it's my clutch fork sticking? He said he had similar problems with his car last year and when he pulled the clutch out it looked fine and was still in spec. He's also a faster driver and his car has aero and slicks. What gets me is that I can't induce it as easily as other videos show (and I don't want to just thrash my car on the streets) so I'm paranoid that I've got early slip but I don't know how much life it's got left. Main thing is that I don't know if I have the time to do a clutch before my next event and I'm a penny pincher whenever possible so I don't want to just throw out a clutch that still has life in it.