Track day question

So I�m finally at the track, first time with my C4S and after first session I have a question. When I break and downshift from 4 to 3 before the turn, when I�m in the turn and start gradually applying gas the RPMs start to increase, like it�s not in the gear, but if I release the gas and re-apply I can actually feel it starts to accelerate, but not as fast as normally. When I tried going neutral and re-sticking it to 3 it would work normally. Another issue is that when I try downshifting from 3 to 2 on very slow corner - the stick wouldn�t go into 2, line it�s blocked or something? Also, couple times I noticed the clutch pedal stuck half way? What do you think could be the problem, is it me not sticking to 3 all the way? But it felt like it was in gear? 🤷‍♂️ BTW clutch is new, less than 1000 miles on it. Could it be PSM? It was on all the time, should I turn it off for the track event? i would appreciate all inputs.

You will be replacing your clutch very soon! Major slippage. "I’m in the turn and start gradually applying gas the RPMs start to increase, like it’s not in the gear, but if I release the gas and re-apply I can actually feel it starts to accelerate, but not as fast as normally"

Does this issue happen well after quite a few mins of tracking, or right away? Tough to diagnose here, but if you are truly in gear and you hit the gas and the RPMs rise, the clutch is not gripping the flywheel, which means that something is holding the clutch back: 1.) boiling the brake/clutch fluid, or the pedal is not returning fully, or your clutch is overheating, 2.) clutch is bad, or something has come apart on the clutch and gotten wedged in there. 3.) Perhaps oil has gotten on the clutch from a leak somewhere (such as RMS). 4.) You could be overdriving the clutch. Are you rev matching on every shift? If this issue only happens after 5 or 10 mins, it might just be a temperature issue (brake fluid and clutch fluid are shared, so bad fluid + temperature = boiling the fluid).

You must diagnose this problem first - Also, couple times I noticed the clutch pedal stuck half way? Maybe the clutch pedal return spring is broken. With the stuck pedal, the clutch plate is not engaging the flywheel tightly, causing slippage.

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hard to say if it happened right away or later, since first few laps I was going kinda slow and was checking how the car reacts and then everything seemed fine. I just yesterday installed new racing brake fluid, so should be no problem with temperature. Also it�s only 67 degrees here now.

It sounds like your clutch is slipping, the clutch pedal not responding properly is another confirmation. From the description, my guess is a failed pressure plate. The job is relatively straight forward I would offer help if you were in North Carolina.

Well, he said the clutch is new, so whomever did the work might need to go back and check it out.

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here�s update after second run. I was braking a bit harder to bring rpms down to engage 3rd gear, that seemed to work. Only once I put 3rd gear on downshift and felt the clutch pedal stuck again half way, so I pressed it again and put stick shift to neutral and back to 3rd and it worked. I�m starting to think this car needs accurate rev match or double clutch technique? I never practiced either before.. I was tracking a bmw m3 before and didn�t have such issues.

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This is either a hydraulic issue or a pressure plate failure. The return spring being broken or disconnected could also cause the pedal to not return fully but certainly not have it stuck half way. RPMs going up in gear/clutch pedal out without much acceleration is another sign of a clutch problem (clutch slipping, which in this case may be caused by the faulty pressure plate).

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ok, third run update. I noticed speed / rpms have to be way lower so that I could downshift to 3 with no problem. If they�re higher, then the clutch pedal stays half way and I have to re-engage clutch pedal and gear. also, I�m not sure if these are connected, but there�s a very slow turn I need to downshift to 2 and the shifter won�t even go into 2nd gear. Again, I have to lower the speed even more to do it. But it all seems wrong, since I�m losing tons of time because of it, this track is very well known to me. so is it me being noob with downshifting or that�s a sign of mechanical issue? I have absolutely no problems downshifting at normal conditions. thanks guys.

When you said accurate rev match, did you mean that you are not blipping the throttle on downshifts? That would explain the 2nd gear lockout, and would be wearing out the clutch and probably syncros. Maybe the clutch is overheating due to that. Try rev matching the downshift at corner exit, if you havent gotten into heel-toeing, and see if the clutch is fine in that session. No need to double clutch on this kind of transmission. (Double clutching just saves on normal syncro wear, can be useful if there are transmission problems or if its really cold outside). The bmw may have had shorter gear ratios which i think would have been easier on the clutch without matching revs, since the revs dont have to climb as much.

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Sounds like a mechanical issue to me. Personally I would not continue tracking a car having this type of issue. My first day taking my 996 to the track last month, I started having misfire and smoke. Ended day earlier and took it home to order parts and fix. If it is a 2 day event, I recommend you seriously consider packing it up until you can get issue resolved.

I agree with others, there is something mechanically wrong. Get it looked at before something bad happens. Check to make sure cables haven’t partially unclipped from transmission (common issue), but it sounds like a mechanical clutch issue. No way the pedal should be sticking.

Sounds like the pressure plate bolts are backing out to me. Common problem after clutch replacement if not properly torqued or Loctited. The Factory even had an issue with this and had issued a TSB on the problem. My suggestion is to not drive the car again until the clutch is removed and inspected for bolt torque and for wear and repaired/replaced as necessary..

Thanks everyone for suggestions. I ended up driving just on 3rd gear yesterday, luckily it was possible))) I went to sleep very early yesterday and didnt read everything right away. Today there was new track config, much faster with hard braking zones. I practiced heel-toe downshifting from 3 to 2 in slow area and it somewhat worked. Downshifting from 4 to 3 still caused troubles. Even with heel-toe after shift the pedal would stay half way back and I had to go back to neutral and re-apply clutch again and it would work from second time. Also, I started noticing that at hard brakes the clutch would go itself down, without pressing it? I drove only 2 sessions and my brake pedal became very soft so I decided I was done for today and headed home. Someone mentioned brake fluid is used to cool the clutch too, so I'm thinking the "racing brake fluid" was not in the end "racing" type? I'll have to ask my mechanic next week what brand he used, but I remember him mentioning that "blue" braking fluid is discontinued and instead there's "yellow" braking fluid. Anyone familiar with this?

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Yep, DOT stopped the sale of any brake fluid that isn�t amber in color. The same fluid that used to come in amber and blue, is now amber only.

Castrol SRF is the commonly recommend brake fluid. It's about $80 per liter, so not cheap.

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It may be commonly recommended, but its also commonly not needed. Motul RBF600 is much cheaper, easier to find right now, and will work really well. Given the OP's post however, I don't think this is solely a fluid issue. Something else might be going on.

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Agreed. Not a fluid issue. It does sound mechanical, especially since the clutch has low miles.

Thanks everyone again, I'm taking car tomorrow to the shop and we'll see what they find.