Free reving under boost

[jakelandry]

Ok i searched and diddnt really find anything... Sometimes (normally in the morning) my car will simply free rev when boost kicks in. I guess my best description would be that it feels like the clutch is slipping without the smell. It does it in all gears and only at 75%+ throttle. My afr's are the same as they always are so im not leaning to a heavy boost leak or anything like that and my boost reads the same as always. My TOB squeaks when i dont have the clutch pushed in but it holds 5500 rpm launches with absolutely no slipping. So im open to any suggestions as to what my problem may be and as always thanks for your contribution.

 

[TuRBoTaLooN]

What kind of miles on the clutch and what kind of clutch? Sounds like the clutch is slipping under load.

 

[turbodude]

+1 on the slipping clutch. Don't know what else it could be as the symptoms pretty much speak a slipping clutch situation. Also, if not the clutch itself an improper adjustment of the clutch pedal witch effects the hydraulic flow between the slave/master could make the clutch fell like its slipping as well do to it not being able to fully disengage. I'd check your pedal adjustment first if you have not done so already.

http://www.youtube.com/watch?v=vYJxQyjIhUw

 

[TuRBoTaLooN]

Good call. Try bleeding the slave and check for proper alignment of the clutch fork through the boot.

 

[jakelandry]

Sorry for just now replying.. I just kind of had a full weekend. I've looked at the clutch adjustment video several times and I never can quite grasp what he's trying to say, but how exactly do you check the fork alignment through the boot? I thought it coul possible be my master cylinder because when I push the clutch in it makes a popping sound when engagine and disengaging, but I'm not sure is that would make my clutch slip.

 

[99gst_racer]

Which clutch and flywheel are you running? And how many miles on it? (you have nothing listed in your profile)

 

[TuRBoTaLooN]

but how exactly do you check the fork alignment through the boot?

RRE has a good wealth of information on clutch adjustment and pedal pressure. Go here: RRE's Clutch And Flywheel Tech Info and go all the way to the bottom for fork alignment. Specifically this picture:

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I thought it coul possible be my master cylinder because when I push the clutch in it makes a popping sound when engagine and disengaging, but I'm not sure is that would make my clutch slip

Check the master cylinder fluid level. If it is leaking you will see the levels drop and should probably replace it. It will typically leak inside the cabin by the firewall, FYI.

 

[jakelandry]

I have none listed because i still have stock both. Im assuming i have a stock 2g transmission but i could be mistaken. My car came with a jdm 6 bolt swap. Assuming i have the stock 2g transmission it has 106k on it. My fluid level doesnt depreciate, i check it regularly for that purpose. I know the clutch is something that is going to go as i modify but i just found it odd that if it was slipping it wasnt smelling bad and why would it only do it occasionally such as when its cold? It holds fine on launches and it even held up to a 2nd gear mishap at 90 mph at the track about a month and a half ago, luckily my head did also but my question is if it was slipping wouldnt it smell terrible?

 

[99gst_racer]

Yes, a stock style clutch would smell terrible if it were slipping badly. Being that ambient temperature is a factor, I'd be more inclined to believe it is a hydraulic issue.

 

[jakelandry]

Ok well I will check all the adjustment possibilities this weekend and get back with yall. Thanks a ton for the help.