so DEVO330 has had the ATS (carbonetics) carbon twin plate clutch installed sept '05. after a good year of use with one day of autcrossing and about 10 track days, the clutch failed. first it was suspected that it was the slave or master cylinder as the clutch grabbed, it just didn't disengage. meaning you could not shift the car without revmatching before putting it in gear.


he said (and i'm sure he will post up here shortly) it broke in the pits at the track when it was cooling off after a session. he put it in neutral to cool off and could not put it back in gear.

anyway, after checking over the hydraulics, and after replacing the slave cylinder, we decided it was not either the master or slave. (the car has a good 90,000 miles on it, so seals as such can go bad). today i took the tranny off and removed the clutch. here is what we saw:



the middle plate had been split in half.

for reference, DEVO330 made 50,000 miles on his stock clutch. he is obviously light on clutches.

the car has a rebuilt engine, TME turbo, Forced performance 300 cams, and all the usual supporting mods with an autronic ECU controlling it all.

posting this for reference to anyone who may have a carbonetics clutch.

the good news is to replace the plate it is only 140 dollars. there doesn't seem to be any other damage to the clutch, and both the carbon disks look fine. the TOB is from a toyota, and is a bit knotchy, and we will be replacing that as well.

 

Wow, I just ordered this clutch. I've heard a lot of great things about it, supposed to be one of the top twin carbons out there. Are they covering it under warranty?
I've been told that this clutch is great for road racing & street driving up to 550 whp. Keep us posted.

 

There is no such thing as a carbon clutch that is good for road racing or street driving at ANY hp level. At least not according to Exedy, Tilton, OS Giken, or David Buschur, all of whom I spoke to recently. As soon as they cool, they start to slip. And apparently the carbon is so good at dissipating heat that they will cool down on just about any long straightaway (and certainly on any highway) and the next time you need it to hold, it wont.

Carbon clutches = drag racing ... and that's about it.

Note where he says "just have to get a little heat in it" ... that's the problem with Carbon clutches on the street or a road course with a few long straights (like Sebring).

 

I own this car and haven't noticed any slip at all. It works fine on the street and road course (Motorsport Ranch anyway) from 330 to 400whp. Under high boost it is difficult to launch hard and smoothly w/out it shuddering, but have not found it difficult to drive and love the light pedal. My engine revs very quickly and sounds great...except....its hard to hear...
The deacceleration chatter/grinding is very disturbing. It is a very unnatural sound to get use to, like something has dried up and is shredding right underneath you! I try to remind myself that its the sound of speed...
With this parts defect, I'm considering going to a heavy duty single plate.

 

My Carbonetics grabs like crazy. Even when the car is cold. I agree that the deceleration noise is like a buzzsaw.

 

So is the porsche carrera gt a drag only vehicle? There are lots of people running carbon clutches on the street with good results. I am having unbelievable good results from my tilton carbon and without the noises everyone else has. The ats carbons work fine cold. I just drove 2.3 35r with exedy tripple carbon. He just switched shortblocks and got to look at the plates with 11k on them. He said they looked like new. the clutch works fine when cold as well. I thought the clutch drove like a dream. he loves it as well. And he had exedy twin metal before the carbon. I think he only got 14k from that one. I think the exedy twin carbon is the only carbon twin that has cold performance issues.

 

Funny you should mention the Carrera GT, it is built almost entirely out of carbon fiber, yet it DOESN'T use a carbon clutch:
"The GT's 5.7-liter, 605-horsepower V-10 engine is based on a Le Mans prototype design, and said engine sends power to the rear wheels through an industry-first small-diameter 6.65-inch twin-disc ceramic clutch." That is from PopularScience, the quote is a link to the article.

And the reason the Exedy triple drives like a dream in a car with a built motor and GT-35r is probably because it's slipping! I didn't say it won't hold at all, but it WILL slip, at least until it slips enough to get hot, then it will grab, hence the smooth engagement. The reason DEVO330's car woks is because he has a 650hp clutch on a "330-400hp car" so I stand corrected, if you use a carbon clutch that has about twice the capacity of what you need, it will probably work well enough to make some people happy.Kind of like a 900hp Exedy Triple on a 550hp GT-35 car.

 

We have installed a bunch of these in the Phx area and all of them are running fine. We have two Twin-Carbon and two Triple-carbon in our shop cars and all are running great w/o issues.

Our Shop 9 evo has the Twin-carbon Carbonetic with 1350kg pressure plate. It recently put down 515whp on our MD. We road raced this car a couple of times last year and drag raced it a couple of weeks ago... clutch is holding up fine.

Don't get me wrong, NO Clutch is indestructible... but this Carbonetic clutch has given us great results... and we have no issues with it so far.

IMPORTANT: these clutches need to be converted from "pull to push" and minor modifications are needed during the install process. Make sure you find a shop that has experience with this; or at least a competent mechanic for your install.

cheers.

 

There is a article with jay leno holding the clucth in his hands. He calls it a carbon clutch. The clucth is called carbon by some carbon-ceramic by others and ceramic by yet others. this article calls the clutch carbon-ceramic. yet it calls the brakes carbon-ceramic as well.

http://www.findarticles.com/p/articl...9/ai_105897604

Carbon clutches vary in composition. The tilton, ats, exedy, RPS, and ACT all use different carbon material in their clutches yet each is still a carbon clutch. I would still call the material made for the porsche a carbon clutch as I would the brakes.

 

Actually, in the article you cited, it says it is a "carbon-ceramic composite and silicon carbide" ... a far cry from the 100% carbon/carbon touted bt RPS and Tilton.

 

So, you spoke to Exedy and OS Giken (in Japanese I presume), DB and Tilton and this is what they told you? I don't mean to flame, but you can't be serious. Tilton told you their carbon clutches are for drag racing only? Uhh, I don't think so. If anything, their clutches (and most carbon clutches) were most specifically for road racing, and not really meant for drag racing.

 

Actually, they were all at the PRI show in Orlando. Exedy, and O.S. Giken speak, and spoke English. For what it's worth carbon does cool rather quickly, which is one reason, (I believe it was Performace Friction) came up with a long strand Tri-Axis carbon weave to keep their carbon brakes hot. The strands are intertwined, then stacked, to retain the heat within their rotors. (Different subject.)
The problem with carbon clutches, is that the material used has relatively short segments (which helps disappates heat) all smashed together. It happens to be a pro, and a con, for clutches. First, you need to heat it up for is to grab. i.e. slip the clutch. (Different temps, for different slippage rates, would explain why sometimes its grabby and other times it's not) The slipping action, combined with the heat, actually deteriorates the carbon on the clutch (which explains why the don't last as long as some might think) A preasure plate with a millionbizillion clamping lbs would cure the initial slipping problems. No flame, just facts. Its just a thought but maybe the heat build up from the carbon caused the cracking.

 

Not even close. The picture shows no excessive heat whatsoever. The condition of the floater shows the clutch was babied.

 

I want a push type clutch

 

Mine is on the way...