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2009 WRX clutch kit recommendations

21K views 11 replies 7 participants last post by  Ruso 
#1 ·
:confused: I have a 2009 WRX and Im looking to put a new clutch in it since ive begun to notice my stock clutch is slipping. The only mods I have done are Cobb Access Port Stage 1 w/ AEM CAI. Ive been told to go with an aftermarket OEM clutch kit and then Ive also been told to do a stage 1 organic upgrade. Im torn on what to do, since I do have an increase in hp and tourque from the cobb stage 1 w/ AEM CAI but then again Im not sure if the gain is enough to justify in getting a stage 1 clutch kit. Any suggestions would be greatly appreciated!! Super indecisive on what to do!! :confused:
 
#3 ·
Yeah thats what I was saying to myself! "WTF why is my clutch slipping!?" I guess when I got the car I was a lil boost happy since I owned a 2.5 RS before, so having a turbo finally was a blast! but I never launched it or anything, just hard charging here and there, but never raced it nor pulled off the line type of driving shit. Oh and one more thing the load feel on the clutch pedal is super heavy and it grabs super high. Im assuming those are indicators for a new clutch is needed??
 
#4 ·
Grabbing super high can be a sign, but generally when your rpm's rise with little or no change in speed is how to diagnose a slipping clutch....

A good way of knowing is putting it into a higher gear, 3rd or 4th, and floor it from about 2k rpm's and see if it accelerates as it should. If it goes for a little bit, then the rpm's really rise quickly with not much speed gain, slipping clutch.
 
#5 ·
Yeah its slipping for sure, just matted it in 4th and the rpms rose but speed didnt. So you would go with an OEM replacement clutch for my set up and it will be able to handle it for the long haul, granted I take it easy this time around haha (Cobb AP Stage 1 w/ AEM CAI)
 
#7 ·
I use that clutch... on an upgraded 04 STi with a 6-speed not a virtually stock WRX with a 5-speed. No, that's way too much clutch for the 5-speed. Stick with stock clutches at that power level. If you burnt it out already, you're probably driving incorrectly. How many miles did you get on it?
 
#9 ·
First and foremost, I hope you are not testing your clutch for slipping by pushing the pedal down hard at a gearing disadvantage (ie... trying to floor it in 4th or 5th below 2500 rpm). It will always slip, but what's worse is that you're putting incredibly bad loads on your motor, not only are you putting physical stress on all components from engine internals (rods, crank), your clutch (which is why it slips) and your transmission... but on top of that you are putting your engine in a place where it will likely knock under these conditions and knock under loads like that can very easily break a motor. You should always downshift to accelerate and generally use higher RPM ranges when driving aggressively (above 3500 or so).

Second, about as important: think of your clutch as a fuse on an electrical circuit for your transmission. When you mess up driving or shift abrubtly or launch hard, the clutch slips a little bit and then engages. Now think about putting a stiffer clutch (even at stock or near stock power levels) and that power delivery becomes instant which feels nice, but this is exactly what puts the transmission under a high risk of failure.

The stock clutch holds a lot of power if you drive it correctly. I currently run 300whp and I actually downgraded form a Stage 1 clutch to OEM equivalent and it only slips when I launch hard with Anti-Lag engaged and/or trying to floor it below 3k in 4th/5th.

My vote goes for stuck clutch!
 
#11 ·
I'll agree on 90% of what Ruso said about slippage, EXCEPT the fact that an OEM clutch shouldn't slip in 5th below 2500RPMs unless you're making more power than stock. Everything else is spot on, especially the part about doing low RPM acceleration is deadly to your bearings!!
 
#12 ·
I said that comment in response to the last one that clearly states a 314hp which is a good amount above stock power levels.

It isn't just deadly to your bearings either. That heavy of load on the components puts your motor in a place where any knock creates much higher forces than normal. Not only that, my gut also tells me these kind of forces can actually help induce knock. So any knock at all can certainly cause bearing damage, but it can also crack things, blow ringlands, bend/break rods, so on.
 
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