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I think I've found the power level where a WRX clutch doesn't hold up anymore. I need something a bit better. Wishing I had dyno numbers to see what torque I'm putting down at the point of slippage.

This SS is running a TD05-16g, 06WRX TMIC, RevTronix StgII and I've been running about 17-18psi regularly. The good news, it's really fast. The bad news, Exedy KSB03 that I put in about 1500 miles ago is starting to slip and flare on the highway (4th and 5th gear). For now I've turned the boost back down to 14-15psi and it's good again.

From what I've read on NASIOC, I'm probably knocking on the door of what the stock WRX clutch can take. People are recommending an ACT, Spec, Stage 1 Exedy, 6 puck sprung hub, all sorts of things.

What clutch should I get that will hold up to my power level and still be OK to drive on a daily driver? I don't mind a bit of extra pedal pressure. (To tell the truth, the clutch feels really light compared to what I'm used to anyway)

EDIT: Maybe it's because the engagement point on the pedal seems really high? It's about 3/4 of the way up from the floor. What would affect that? Can I fix it without buying a new clutch? I'm thinking it may not be engaging all the way with the pedal out.

Looks like my clutch pedal adjustment was keeping some pressure on the TO bearing even with the pedal all the way out. I adjusted the master cylinder rod and it seems to be all better.

Cool beans. I think my exedy OEM turbo legacy clutch slips a bit in boost in 3rd gear and 4th. It's difficult to tell but it feels like when I get on it the car doesn't accelerate like it should for a couple seconds.

kimokalihi wrote:Cool beans. I think my exedy OEM turbo legacy clutch slips a bit in boost in 3rd gear and 4th. It's difficult to tell but it feels like when I get on it the car doesn't accelerate like it should for a couple seconds.

idk if mine the same thing but in my 93 22t motor 3rd and 4th once i hit about 4500rpm are so it woudnt move for a few sec then it would pick up so is that like the clutch sliping it needs a clutch anyways because its crap lol no wories right now lol dont got it going yet

Yup sounds like a slipping clutch to me.

Yeah, sounds like a slipping clutch to me as well.

Kimo, I've been watching your build thread (and read all through it!) for a while now, I'm a bit surprised you've been running an OEM T-Leg clutch. But I cannot say that I'm surprised it could be slipping a little bit. Maybe one of these days I'll get to see your sweet ride in person at a gathering or something.

yea i probly read alot of kimo thread.. some day ill look from start to end but 50+ pages WOW... so sense ill be replacing the clutch which one should i go with

go for a stage 1-2

What's your full mod list? I'm about to put my TD05 + robs tune in soon, I'd hate that the wrx clutch i just put in fail alrrady

Alphius wrote:Yeah, sounds like a slipping clutch to me as well.

Kimo, I've been watching your build thread (and read all through it!) for a while now, I'm a bit surprised you've been running an OEM T-Leg clutch. But I cannot say that I'm surprised it could be slipping a little bit. Maybe one of these days I'll get to see your sweet ride in person at a gathering or something.

Thanks! If you want to check it out I will be attending the subaru show this saturday at pacific raceways. I'm not in the show, just gonna come check out some sweet subarus and hang out with Florin and Mike and a friend of mine from work. I probably won't be there til around noon-onish though since I work nights and usually sleep til 12-1pm. I'll get up a bit early for this. It's not looking the prettiest right now but hopefully by the time WCSS rolls around I'll have the roof painted and the sideskirts on and the gauges mounted properly in the dash.

kimokalihi wrote:

Alphius wrote:Yeah, sounds like a slipping clutch to me as well.

Kimo, I've been watching your build thread (and read all through it!) for a while now, I'm a bit surprised you've been running an OEM T-Leg clutch. But I cannot say that I'm surprised it could be slipping a little bit. Maybe one of these days I'll get to see your sweet ride in person at a gathering or something.

Thanks! If you want to check it out I will be attending the subaru show this saturday at pacific raceways. I'm not in the show, just gonna come check out some sweet subarus and hang out with Florin and Mike and a friend of mine from work. I probably won't be there til around noon-onish though since I work nights and usually sleep til 12-1pm. I'll get up a bit early for this. It's not looking the prettiest right now but hopefully by the time WCSS rolls around I'll have the roof painted and the sideskirts on and the gauges mounted properly in the dash.

take some pics of your cars together and posiple other subarus from the show

Will do for sure.

guess im riding there solo...

You're probably going there early huh? Can't do that. Wish I could but I get off at 4am and have to come back after the show and go back to work. Sucks balls.

Yeah, I'll try to make it there next weekend, I was planning on going but a few friends might want me to come camping with them that weekend instead.

I just drove about 900 miles this weekend, and so far the clutch hasn't slipped again, so the WRX clutch seems to hold up to this much power for now.

For a mods list, it's just a stock head EJ22T with 440s, TD05-16G, 07WRX IC, desnork, full 3" catless TBE on a RevTronix StgII (will be going RobTune soon). I run 11:1 AFR at 17-18psi; I am probably close to maxing the 440s.

hmm, seems weird that you're pushing the wrx clutch to its limits. that seems like a common setup now.

Just an FYI, I'm running a stock WRX clutch & PP with an Exedy LW flywheel and I'm around, if not a little higher than stock STi torque levels.

91 octane vs. 93 octane
91 octane vs. 06 STi

The longevity of a clutch is going to be heavily dependent on how you drive.

Alphius wrote:I am probably close to maxing the 440s.

They do get maxed out if the ECU ever goes into limp mode (aka octane factor below 50 or 25%...I forget which). Data logging of this in http://bbs.legacycentral.org/viewtopic. ... 72#p314372

For anyone interested, the clutch pedal adjustment rod was adjusted incorrectly and was putting a small amount of pressure on the clutch while driving with your foot off the pedal. This is what caused the slippage. Since I have adjusted it correctly, my clutch is happy as a clam at 17psi. No problems.

I would expect the stock WRX Exedy clutch to hold this power level (and a bit more) easily, my entire problem was in the adjustment.

I understand the longevity being dependent on driving style, and my driving style is very easy on clutches. Even if I was terrible at driving stick, having a brand spanking new clutch only last 1500 miles would be completely ridiculous.

Sweet good news! I was scared there for a second lol