OEM disk and ACT HD pressure plate max power?
 

I am waiting on my KW supercharger kit to arrive and need to start planning on a clutch upgrade. The most I ever think I'll get out of the car is about 500whp (doubt that'll happen though).

My car has only about 3800 miles on it, and the stock clutch feels like new (and I'd venture to guess that it's "like new"). Does it make sense to just add an ACT HD pressure plate, or will it even hold up to 500whp? Or should I get an FX300?

Also, is there a light(er) weight flywheel than the OEM AP1 that you would suggest, or should I just go with OEM AP1?

Thanks for any feedback!

It seems that 350 w/tq is the limit of the OEM friction disk, which you'll never see even at 500whp supercharged. Some have reported going to 400 w/tq and still being okay, but 350 seems to be the maximum consensus-wise. Regarding the AP1 flywheel; that's most likely the best option. The lighter weight option is the ACT Prolite , p/n 600350, coming in at around 8.3? pounds. Seems to have a lot of glowing reviews on here....I'd spring for the Prolite, as I will be. Even though I have an AP1 I'm not too keen on resurfacing flywheels, and have just always replaced them. I have a lightweight flywheel in my daily civic Si that I put in there when doing a clutch job and really like it.

The FX300 is basically the same as the OEM/ACT combo.....but you'd be spending more money. If your car is low miles I'd give the clutch disk a quick inspect and the splines and bearing a nice coating of the Hi-temp Honda UREA grease, bolt on an Ap1 or prolite fly with the ACT HD PP and call it a day. You can't go wrong either way but the ACT/OEM setup has been around forever and seems to be the forum favorite. If you don't need to replace your disk I'd definitely go that route. I'm doing my full clutch and flywheel (my car has 53k miles) and I opted for the OEM/ACT setup over the FX300 because it has a long history of satisfied users and reliability.

After three years with the ACT PP and OEM disc at 405rwhp @ 8,500 rpm, I decided to do a disc preventive maintenance replacement. The used disc was still 8.3mm thick which is within the "new" specification for the S2000 clutch disc. The replacement disc is still sitting in a box in the garage another three years after that.

Exactly the info I was looking for. Thanks guys! Looks like a flywheel and pressure plate are the ticket.

My act/oem setup started to slip at 350wtq. I had about 30k miles at the time.

350wtq on a SC is pretty unheard of. ACT pp and oem disc will be plenty. I ran the SOS street pp and oem disc with a maxed out NV1200/18psi and no problem and that's supposed to be lower rated.

ap1 flywheel because cheap and anything is better then an ap2 flywheel, or 8.3lb act pro light flywheel if you want the best.

Also something vital no one ever mentions is you DEFINITELY have to use AP1 slave cylinder or delete the Clutch Delay Valve on AP2 Slave Cylinder once you go forced induction. That built in 'clutch delay' slips the clutch ever so slightly while shifting but doing that with more than 250whp is a quick recipe for a burned out clutch.

yeeaaaah, thats not true at all. I ran a cm fx500 as a daily in atlanta traffic for over a year...never burned the clutch at and I was at 508hp with ap2 slave

Just comes to show some people don't know what their doing. Running a clutch delay valve on a 500whp S2K SMH

And what technique is that? Shift slower?

didn't you Just recently turbo your car while asking a billion rudimentary questions? But you're an expert now... sorry I forgot.

My clutch was fine when removed and im now running a carbonetic triple disc...guess I still don't know what im doing

The CDV sucks anyway, just get rid of it.

umm you do know that high powered drag cars run clutch delay valves to put less stress on the transmission right? Look up the tilton flow control valve.

no not the speed

you need to change the timing of your hands/feet

:bigpopcorn:

I use a CDV without any issues and I’m at 400tq+. It went back in after blowing a transmission. The only time I noticed slippage was when I was NA with stock clutch setup.

The Pressure plate and flywheel arrived today. I will ask whatever shop changes the clutch to do the CDV delete. I can't stand it even with a stock car, so it's going away. I won't beat on it very hard anyways. Flat shifting a 700hp Viper and feeling the transmission degrade over 15000 miles makes me realize it's not worth it.

Here is one very good take on the S2k drivetrain everyone should read it i take no credit just spreading the knowledge. I have driven tens of thousands of miles with CDV and without. I think the biggest take away is DO NOT run clutch delay valve with heavy AP2 flywheel and highhorsepower unless you granny shift or have a $2,000 highend clutch that makes up for the CDV slippage. I could see a lightweight flywheel actually being ok with a CDV but i have never run that so i will not comment. When i went Turbo with AP2 OEM Clutch and flywheel with CDV i thought my clutch was slipping when shifting especially from 3rd to 4th or 4th to 5th and 5th to 6th gears but it was infact the CDV intentionally slipping the clutch so i had to wait to shift until the revs fell and clutch bit. After removing CDV and staying with heavy AP2 flywheel i immediately noticed i didnt have to wait for the clutch to bite and was able to go full throttle sooner between high loaf shifts. Anyway here is the best take i have found on how it all works on S2K:

Demystifying the S2000 drivetrain


Here is some proof of how a lightweight flywheel and no clutch delay valve enables quicker shifts. Now all you ap2 owners with heavy AP2 flywheel and CDV compare for yourselves with your setup. Maybe post up proof CDV enables quicker shifts and end the argument once and for al but like i said i've tried both and CDV delete is the way to go.

Dude your videos are awesome how do you get all the tacho's video combined? Your car sounds absolutely insane too!
Do you have an example of a clutch delay valve video to compare?

Thank you, I have AEM INFINITY and use AEM DATA software to do the video overlays. I tinkered with the software alot but finally got it to my liking. If anyone has AEM INFINITY id be happy to share the settings so you can get the same look and sensor readouts video overlays. This is an excellent tool to see and share how certain setups do on S2K. The car is on oem exhaust and all the sound came from the two external wastegates. I do have an old video of the CDV actually i will try to dig it up.

I need to watch that video but for me personally I had to change my previous AP1's slave cylinder after the crappy puck clutch the previous owner installed blew out on the highway at 170mph. The clutch fork blew out of its hangar as well. Slave cylinder sprung a leak as a result. Swapped it out with an '04 or '05 version but I knew it would have the annoying CDV so before installing it I got my friend to help me remove the annoying thing... then I installed it. I fully understood what it was designed to do and as Kyle will tell you when you drive an AP1 you are used to the immediacy of everything, absolutely everything and the last thing you want is for any of that race car quickness to be dulled so, hell no to CDV. Thank you.

Solid advice. I'll probably go ACT/OEM as well if my OEM disk needs to go when I slap the blower on that is... I'm curious, what do you think of running the Spoon version of the OEM disk with the ACT PP? Spoon says it holds 30 % more than OEM. Check this out: https://www.rhdjapan.com/spoon-sport...s-ap1-ap2.html

Ehhhh....the standard OEM disk has been proven to hold beyond torque levels that it will ever see on my car. If I'm lucky my car might see close to 300wtq progressively because supercharged, and that's absolute maximum. I did the conversions and the spoon disk is roughly $110 more shipped to my door over the OEM. That's 62% more cost for supposedly 30% more clamping force that I don't personally need. Not knocking it; I'm sure it's quality, and I suppose it has it's specific place for certain individuals and power levels. I'm all set though lol.

True :)

I went for the ACT HD Pressure plate, and Competition Clutch ultra lightweight flywheel (supposedly a tick under 9lbs).

I suppose if I even dare to shift like I used to in my Viper, I'll shatter the diff? I went through three differentials on that car, but not from racing (they all started whining during the break in period)

That's some QUICK shifting. I havn't seen an S2k shift that quickly actually. From what i've read diffs blow mostly from hard/not hard enough launches for an S2K. To physically shift that quickly i think we'd need a short throw shifter and a quick release master cylinder like this:
Blox Racing S2000 Quick Relase Master Cylinder

I might have to be the guineau pig and try it out the MC mod seems interesting.

​​​​​​Do you think the transmission could handle it much at 275-300wtq? The Viper and s2k have very similar shift characteristics so I'm sure it can be done, I've just never tried it because the ap2 clutch/cylinder slip doesn't make it any more beneficial. Plus the 245 rear tires are 110mm narrower than the Viper's, and the Viper would never hook under 70mph (in that video traction control limited the slip whilst shifting to 2nd at 65mph+).

The S2000 destroys diffs from regular half ass burn outs where the wheels hop and chatter, eventually flexing the carrier bearing end caps pulling the ring/pinion gear apart, that's the first and most common failure in our diffs. Quick shifting done improperly can break gear teeth in the trans. Less spinning inertia ie light flywheels remove shock load from the drivetrain, which is a good thing, because the rpms drop quicker between shifts and you will naturally find yourself shifting quicker to stay in the powerband anyway. A stock ap2 with its 22lb flywheel requires ridiculously slow shifting in comparison because the rpms just hang in the air, and rushing just engages the cdv and or just compromises smoothness and precision. Its like driving a sowing machine. that said, the s2k trans isnt bullet proof. Ive been through a few of them all due to secondary bearing failures. That can happen stock or boosted, but more so boosted. Really high boost guys in the 350+ trq range seem to blow out second gear first. but I think that's just do to raw trq/twist. The bearing issue over more prolonged abuse. If you drive spiritedly but determined and precise i think the s2k drivtrain overall can last a while at most mid/high boost supercharged set ups, because even at 400whp they are typically only putting down 230-250trq.

Ouch. Was that while you were running semis and on a drag surface with high bite? Diff fluid you ran up to that point?