djsilverjohnson

I built a Nissan 240sx for DSP class autocross in 2006 and installed a Centerforce OEM replacement clutch kit. The car weighed the same as the S2k and ran Hoosiers. My wife and I both drove it and we slipped the clutch without mercy on starts. We never had a problem with it slipping and it was still holding up when we parked it the end of 2013. I later parted it out and the engine/transmission is still running in someone else's car.

We bought a 2003 S2k on a whim in Feb. 2014. The car only had 45k miles on it but had been autocrossed extensively by the second owner. We typically co-drive in 15-20 autox events/year. I wasn't too surprised when the clutch started slipping at a two-day event mid-2015. I put an OEM clutch kit in and it lasted until May of 2017 before it started slipping. This time I put an ACT heavy duty OEM replacement kit (30% more clamping force). Wife went to the Dixie national tour in Valdosta, GA without me this year in mid-March (I had to work) and the clutch started slipping while she was there. She had to drive very carefully on the way home, as it would slip over 60mph. I decided to go back to an OEM clutch disc but retained the ACT PP, as I've read a number of comments preferring this setup (and it's less than a year old). When I pulled the old ACT disc out it was down to the rivets.

I know the S2k clutch disc is small (8.25") compared to the 240sx (9.5") and we've been hard on them. This time I set the clutch pedal so that it engages the clutch early, to discourage slipping it. We've also had a heart-to-heart discussion about the way we launch the car and will try to ease up on it.

I do have one question about the slave cylinder. Even with hydraulic pressure released, The release lever is pre-loaded slightly. It's not much but when I placed the slave cylinder pin in the release lever pocket, I had to force the slave cylinder and release lever forward about 1/8" or so to get the bolts in. I figured that is to keep the release lever and TOB from rattling, but there's no specification in the FSM. I'm using an OEM AP1 slave cylinder. Is that normal? Thanks

Jub

When I began autocrossing my car, I searched all over to find the best technique to launch. I define best as a combination of safest and fastest. Most of what I found suggested revving between 6-7kish (will depend on surface and tires), letting out slowly just to the beginning of the engagement point to take up drivetrain slack, and then basically dumping the clutch. This should all happen within a second. Do not ride the clutch much at all and feather the throttle as needed. The goal here is to keep the tires spinning slightly until hooking up right around the vtec point (6k rpm's).

The thought process here is that traction endangers the drivetrain more than spinning. Abruptly breaking the wheels loose should be easier on the clutch and differential than revving to 4-5k and slipping the clutch. It is pretty hard on rear tires but supposed to be easier on the drivetrain. Note that it is definitely not easy on it by any means. I've seen some old school posts from the stock class hoosier days claiming 60k+ miles and years out of the oem clutch driving this way. I do not launch my car all that much but have done it this way some over the last 2 years and 20k miles on RE71R's. As far as I know, I'm on the original clutch at 106k miles. Mine still feels plenty strong. I was definitely hesitant but pretty much all legitimate search results I found pointed to this method. Good luck!

ConeKiller2

Stock clutch in every s2000 I have autocross. Current setup on 315 Hoosier with no issues in bsp. 4500rpm and dump the clutch if launching

exigex

I have found that dumping the clutch at around 5500 RPM works great for me when I launch, I am running Continental Extreme Contact Sports right now.

Ricky_Flowers_

My OEM clutch lasted to over 150,000 miles, with 5000 or so of those miles done on track. Never slipped. The only reason I changed it is because the throwout bearing started to make an interesting noise. I replaced my original clutch with all OEM components with the exception of an 8lb flywheel. 8000 miles, 1500+ track miles, 230whp and zero slipping.

ZDan

My OEM clutch lasted 230k miles including ~2500 track miles :O
Never slipped, but something in the mechanism finally got hung up and snapped, so new clutch a little over a year ago :P

BoboTheMonkey

I'm at just under 100K and as far as I know have the stock clutch. Pretty much all of my miles now are autocross. I bring it up to around 6 grand and dump it enough to spin the wheels a bit. Tough to say what happened without actually seeing you launch. I try not to burn it up too much. My WRX I had was different, I had to burn the crap out of the clutch or the trans would probably explode. I did have to replace the fluid in my slave cylinder since the clutch was engaging with the pedal all the way to the floor. Like you said, maybe you needed to have it adjusted closer to the floor. Mine starts to engage almost immediately. Not sure on the last part of your question though.

TrumpetTitan

I have 174K miles on my car with the original clutch. I do 12-15 local autocross events per year, and have been autocrossing since 2011. However, I don't launch the car, I just release it slightly faster than I would under normal driving and then apply full throttle once the pedal is all the way up. I may decide to learn a launching technique for national level events or ProSolos if I ever decide to do those.