I'd like to hear some feedback from folks running organic clutches, such as the JWT, RPS, or Clutchmasters setups, on built motors with cars making 500+ft/lbs of torque.

I ask because I've seen many claims on these forums that a simple JWT clutch/flywheel combo, for instance, will handle up to 550ft/lbs without slip. While that sounds great, in practical application it just seems a little out there to me.

Example - Audiblemayhem is running the RPS 6-puck clutch/flywheel combo, which is one of the stoutest organic clutches on the market. The car was putting down between 500-600 flywheel hp, the clutch was burning like mad. It smelled awful, and could barely hold his power with even a rough tune.

So, what's the verdict on the non multi-disc carbon clutches and 500+ft/lb built motors? Is it REALLY possible to hold this kind of power without a carbon disc clutch? To me it seems like it isn't possible, and that people have been stretching the truth a bit when it comes to them and big power.

 

This really depends on whos driving it and how often its getting ragged. Some like Jeremy have trouble at that power level, others like Phunk I believe ran and maybe still runs a JWT at 460whp+ and dont have issues. FWIW, I plan on keeping my JWT clutch in till it fails. Everybody will have a different experience in this matter and it will be hard to establish the power level of failure. Some guys ride the *** out of their clutches daily driving, and they would never admit it-then they b!tch when their stout clutches are slipping...

 

I am running an excedy stage 3 clutch and put 2700 boosted miles on it and its been perfect at 518ft whtq

 

It would be nice if we had a good chart or sticky with a list of all the clutch options and info including clamping force, pedal feel, engagement point, power potential, and price. Perhaps it would make the choice an easier one for others.

I was personally thinking of the RPS setup but have lately considered just buying the JWT combo and pushing it till it burned out. The problem is that on a single turbo Z, even with an upgraded t66 turbo, you'll be putting down more torque than power. This will toast the clutch faster than most TT setup's power delivery that I've seen.

 

got my ATS triple carbon now, going to throw it in really really soon...


cant wait!!!!!!!




jeremy

 

Ive seen so many RPS clutches burn out on many cars under what they rate them Id never buy one. If I had to spend the cash Id do an ATS clutch-get some KY and bend over though its gonna hurt

BTW-does anybody know what the highest stage ACT clutch made for our cars will hold? They are GREAT clutches for the money, and could be an alternative to an ATS...

 

RPS clutches suck @ss. I am not sure why i see so many people that say they are decent.... i have never had anything but issues with them personally, and then everyone i actually speak to that has used them have had slipping issues as well.

For instance, between 2 WRX's I had, I used the RPS on one and it lasted for ****, i got a replacement, same thing!! (drag race, autoX, and track events). Then with an ACT, it was just fine. On a boosted Integra, a Clutchmasters worked great.

On a boosted ~500hp G, the JWT lasted just fine, and the ATS triple is the best thing since, .... since Goober pb & jelly.

So basically, with every clutch i've used i've had no problems except the RPS (that's with each clutch type/level correctly used in the given application). maybe i just have bad luck with them, but i'll never buy another RPS with all the other options available. fwiw, the supra guys seem to like them though...

 

550ftlb

 

There single plate organic (ACT clutch by the way), claims to hold 450 lb/ft.

 

jeremy,

did you ever figure out if your RPS clutch was the sport 6-puck or the Max 6-puck? the way it gave out on you, it makes me think it was the sport 6-puck.

Andrew

 

I find it hard to believe that an RPS 6puck w/ max pressure is failing at 500whp. We've used them in a lot of cars, and havent had any problems at all. If the clutch is slipping on the dyno, there is something else going on. Was the clutch properly broken in? Clutch life is almost entirely dependent on how much you slip it. Lots of slipping to start the car, or lots of slipping when drag racing will destroy any clutch pretty quickly.

The RPS 6 puck with max pressure plate is my favorite non carbon clutch. And is rated at 625ft/lbs flywheel, which seems like a solid 500-525whp to me. Beyond 550whp, you really need a twin or triple disc carbon ATS/Carbonetic.

Has anyone looked at a JWT clutch disc before? Almost completely stock. in fact, you'd be hard pressed to tell the difference. Slightly Stiffer springs are the main difference between a JWT clutch and an OEM clutch. The flywheel is really nice though.

 

Hmm... even more confused. I'm still not sure what to think about RPS, quality-wise. Thanks for the feedback, though, Sharif.

Basically, I'd like to take a built and cam'd shortblock as far as I can take it without going carbon disc. The whp figures you're putting out seems to be based on a TT application, however. I'm concerned with a high TQ single turbo setup will burn up a clutch easier than a TT at similar power levels.

Right now my car is making 4.6% more peak torque than power. With 15% drivetrain loss factored, and the same hp/tq ratio scaled from my last dyno run, this means I'd only be able to put down in the area of 500whp without exceeding the limits of the RPS 6-puck max (assuming the limit is 625ft/lbs flywheel). Not very promising, if you ask me...

 

You are correct, in that any way you slice it you'll be near the limits. Keeping in mind the approximately $600 labor bill for labor, might make sway you into biting the bullet now...since labor will be free, and getting the carbon twin or triple. They will last a very long time.

Hit me up on PM for pricing.

 

not to start any debates of whose dyno puts down accurate numbers or whatnot but this RPS clutch held EXACTLY 470 hp dynojet SAE numbers slipping like crazy, that was at a weak 13 psi with really conservative timing, it wont turn up past 13 psi without slipping.


this RPS is not a bad clutch if you are putting down smaller numbers... i never would buy another one...

 

Heard good reports about RPS.
I'll let you know how I get on with mine.

 

I am not disputing you either. But 470whp on a dyno...no matter what dyno, can probably be held with even a stock clutch. Slipping and drag racing is what destorys clutches. Holding power through a dyno run doesnt tax a clutch tremendously, unless you have exceeding the holding capacity of the clutch.

Which RPS clutch/flywheel did you use? If you used the street disc (full face), it wouldnt suprise me if it slipped.

 

Just an FYI the ACT Street Disc clutch (what I'm running) is rated at 519 ft/lb by ACT. That being said Turbonetics is running the ACT Street Disc clutch and Prolite flywheel on their Stage 2 G35. So far no issues.

 

all jwt carbon hupla is the only thing i dislike coming out from there. In my SR days fwd they said the same about the same clutch holding 400hp on my sentra.. heck no burned it right up on first pass spoke to clark got another same thing so gave up and ran a puertorico clutch 6puck nonsprung with hd pp. JWT clutches are CM

 

Cool.

 

I have been running my JWT set up for almost 8K boosted and it has never slipped yet.