Is It the Clutch or something worse.

[racingbreed20]

Need a little help here before I start taking my transmission apart....
Last night went to Mizugama again to race...did a few.. fun stuff.
Until I lined up again Launched at around 7 grand (good launch good spool) I hit second (thrown back into the seat again.....and then no more accelleration. WTF!! Try it in third and as soon as I start to get near max boost around 5,000 RPMs I get the feeling like I just stepped on the clutch pedal. Try running it up again and every time I get on it and it hits around that RPM level I loose mad power but the RPMS continue to go up. I thought my clutch might be worn...Its an OS twin plate... but hey it might be old. But wait The clutch engages fine in all gears at low RPMs daily driving isn't a problem and she still produces good get up. How about the pressure plate...? Something is causing a power loss when I get up there. I still think the turbos are fine no wierd noises no squealing they'll will hit max boost.

My car = Money pit

Every now and then people list the MODs their cars have

heres a list of my malfunctions

AC went out
CD player burned up
front speakers went when the volume never got high enough to hear
Valve covers have a nasty paint job
Hoods a little crooked
Radiator crack had to replace that one
And now the mystery possible clutch problem
Look if it is in God's plan to have me struck by a meteor than at least he can do it when I've finnally hit over 300kph

[RazorGTR]

It could be, but sounds like you have a boost leak. check all your hoses very closely.

[Moppie]

Very simple, if the revs are rising, but the car isnt acclerating the clutch is fried.

Good luck, a boost leak will be cheaper and easier to fix, dropping the g/box out of a skyline is not something I would want to do.

[Gonthrax]

When you feel the power loss, are you still making full boost according to your gauge?

[GTES-t]

Hey dude, I had the EXACT same problem! Car would do fine until the clutch/transmission got hot (from a couple of runs) then it would constantly slip under high RPM's or when shifting while racing. I hope your causes are the same because it'll be a simple fix.
I thought my nismo pressure plate was the cause for mine so I swapped it for an OS Giken twin plate and it held great for quite some time then started to do the exact same thing! So, I was starting to check the clutch out when I pulled off the slave cylinder and noticed that it extended out on it's own rather quickly. I tried to push it in an I could not do it by hand, I had to force it in using the transmission housing. I figured the master cylinder was shot and already had a repair kit so I rebuilt the master. It was the first one I ever did and checked out how it worked. I noticed a pressure release valve that is hit when the pedal is all the way back and it only has about an 1/8 inch of movement if that.
After putting everything back together, I checked the clutch pedal and undid the switch stop that dictates where the pedal stops when it is out. As I screwed the switch back, sure enough the pedal was also coming out. I did this untill the pedal stopped and retightened the switch in place. I double checked the slave cylinder and sure enough, I could push it in by hand with little resistance.
I don't know if this is the same cause of your problems, but I hope it is just for the ease of repair!

[racingbreed20]

Thanx for the tip. I did notice that at night around here the car was much more responsive. At first at least until she got a little hot. The fact that I could always boost up to my 1 bar limit and slow down at the same time, bothered me. Thought I had a leak in the piping somewhere. Ofcourse I've got all sorts of time to figure this out, as you've might have read in my other thread (long road ahead). I just hope I can store my car somewhere like typhoon motors until I can get the money to fix this thing. Thanx again!

[Moppie]

Sounds like you've got a lot of moisture in the clutch fluid (Which is just brake fluid) and its thinning out as it gets hot, which is screwing with the clutch activation and the above mentioned pressure release.


You might only need to bleed the system enough to replace all the fluid.
While your at it I would do the brakes as well, if moisture has gotten into the clutch, then it will deffinitly be in the brakes as well.