This is a post I did on the FD thread on Ausrotary, though some of you might get some benifit from it if your in the market for an excellent street/race clutch....

http://ausrotary.dntinternet.com/for...725&start=2340

My post.........

Anyone in the market for a replacement clutch may be interested in this little bit of feedback.

I recently changed my worn out stock SP clutch. After being fu(ked around on e-bay on a HKS twin plate I got NENGUN to supply me a special order Exedy D-Core semi carbon twin plate kit. They now list them on their site

This clutch is amazing :shock:

Totaly drivable like a stock std car (I feel its better) have not stalled the car once in over 500+ starts *part of running in procedure* and the take off's in launch mode make you look like a pro driver, clutch modulation is out of this world and it can be slipped without issue for a perfect stress free launch or quick take off.

Clutch was around $2550 delivered well worth every cent, why people fu(k around with old technology is bewildering after using something this damn good. If your worried about cost simply weigh up that you will be paying for 5 or more conventional clutches & flywheels + 5 lots of labor to get *if your lucky* anything like the life of a true racing clutch. You will never ever get the drivability nore the level of control a Carbon clutch can offer.

[Operating advertised limits]
12000rpm peak speed
68kg/cm or 670Nm torque
Around 750bhp in single turbo 13B form
And totaly drivable like a Toyota Corolla

BIG NOTE! If you get one you MUST run it in exactly as described, for those of you that run dual carbon SBS pads its a bit like this process, then carbon plates need to transfer material to the floater disks and do it in a gentle fashion when new (500 gentle below ~ 2000rpm starts, no big loads/acceleration during this period), then it has a prescribed second stage to finish off the process (5 racing starts @ 5000rpm). then she is ready for full action



Advertising blurb ........ lives up to it and then some !

Hyper Carbon Series D-Core
D-Core is the new generation of clutch systems by Exedy. The revolutionary carbon clutch system is developed to achieve the ultimate goal of comfort and ease of operation. It is purpose built to absorb the noise and vibration emanating from the drivetrain components such as differential gear, transmission and engine. The D-Core system is designed to protect the drivetrain by absorbing and dissipating "shock torque" and is especially effective in vehicles fitted with 6 speed transmissions. Superior engineering enables the D-Core clutch system to possess an ideal clutch engagement position, increased clamp loads and lower pedal effort, while the unique carbon fibre friction material allows comfortable half-engaged clutch operation and responsive gear changes.

Hyper Carbon Series Multi D-Core


Introduction of a damper to absorb and dissipate noise and vibration.
With the reduction in pedal effort and an increase in clutch disc size to 225mm, the D-Core Twin clutch is ideally suited to high performance vehicles.
By optimizing the weight and inertia of the D-Core clutch system drivability is improved at low speed.
Boss Drive with unique sports clutch sound.
In 1995 Exedy provided clutches to a top F1 team. One of the the primary features of Exedy F1 clutches, carbon clutch technology, has now been introduced into performance products for street use. The carbon clutch series enables an improved shift feel and easy clutch operation which are requirements of performance clutches for street use.

 

The multi plate clutches from Exedy are great in terms of pedal modulation and torque capacity.. the only problem they can be noisy at times

 

My boss tried 2 Exedy Twin Carbon clucthes in his evo, and both were slipping at 450whp. Now he has ATS Triple Carbon.
The Exedy was nice to drive around, but I think they messed something up on the design of the evo8 pressure plate (pull style).

 

True "Unique racing clutch sound" LOL It sure is with the pedal depressed, totaly different noise to the Tilton's I have used prior. The noise on clutch depress I have to say is far nicer than the noise of non sprung centre whil in gear though and it is a hell of a lot kinder on the drive line..... very impressed with this aspect of it.

Torque capacity will be directly related to how its run it (asuming the EVO one was made right I guess) but can definatley vouch for the fact that the clutch only came good after the pre requisit 500 soft starts (300km city driving roughly) followed by 6 racing starts, after that its a gem

 

Oh oh, now you're done it.
You're leaking secrets out to the masses!


-Ted

 

WOW, I haven't really seen Rice racing post since like 2003. . . . that or I just missed his posts over the past 2 1/2 years. . . . How have you been?

 

They have been few and far between, I have been well

 

Great post Can you tell me more about the noise you are experiencing from this clutch. Is it annoying? Loud? Embarrassing, where it sounds like your FD is about to fall apart? Any info. would be greatly appreciated.

 

i'd like to put a strong plug in for my Exedy Hyper Single...

this is not meant to hijack the thread or minimize the Exedy carbon twin but to add another really great Exedy clutch option for those not in need of a twin plate or not wishing to pony up the additional cost.

i have 6000 miles on my Exedy Hyper Single and it has lived up to the optimistic expectations i had when i bought it. since mine is approx a year and a half old ( i don't drive my car in the wisconsin winter) i have the pre-carbon cerametallic disc.

i love it.

it slips just enough and it locks up tight. the setup is rated at 400 ft pounds.

anyone looking at a conventional clutch setup.. an ACT or Spec etc etc should take a careful look at the features of the Hyper Single. the flywheel is purpose built of chrome moly so it won't take your legs off. the disc is sprung and will be either Exedy's patented cerametallic or carbon. the disc rotating mass is light so it can be shifted fast without screwing up the syncros. the cover is forged aluminum just like the double disc and has internal fins to promote cooling airflow. pedal effort is comfortable thanks to a different leverage ratio than the normal style clutch.

Exedy is the research arm of Daikin, a multibillion dollar a year company that makes most of the OEM clutches for Mazda, Toyota, Ford etc etc. no problem w an R&D budget and it shows. most of the Exedy "competition" reworks stamped clutches w more spring rate... these start as the vanilla Daikin OEM product.

for approx $1000 you can buy the flywheel, disc and clutch cover and, if you are making 450 rwhp or less, really have it all... a true race clutch that is easy to drive.

anything more than 450 and you'd be wise to buy the double disc.

if you want more info search Exedy Hyper Single.

howard coleman// unaffiliated w Exedy, just a happy customer

 

The noise the eminates is when the clutch is depressed and the steel floater plates "clang and rattle" against the driven lugs on the flywheel, its a unique noise that is not disturbing at all its just a reminder of the serious nature of the clutch

If it were not for that noise (only noticable when engaging pedal to allow gear selection) you would never pick the twin carbon from a stock std clutch its that good in drivability, but its light years in front for slippage, modulation, torque capacity and low inertia + balance.

After proper run in (for carbon models) its function/capacity is first class

 

I have never tested them myself but a buddy of mine had the same issue with his evo. But after some heat it would work fine.

 

Carbon racing clutches have a low coefficient of friction when cold, Exedy and even tilton state that you need to slip the clutch in preperation for it to take its maximum torque capacity.

Exedy's recommendation is to slip the clutch 3 times for up to 5 seconds each time at which point it is ready to take full torque capacity.

This is achieved in my car by sliping it off the line @ 5000 to 6000rpm in 1st gear, which is the ultimate for take off's anyway and least amount of dive shock to gearbox and drive shafts, or you can slip it onthe brake while staging waiting for greena dn build boost (I have herd some cars doing this very effectively with carbon clutches). Alternatley you can slip it (warm it up) in the burn out box or on your warm up lap or out lap for a circuit event.

Once she is warm its all go

All race derived Carbon units (remember Exedy made them for Ferrari in 1995) and Tilton have for many F1 teams too operate the same way in long life semi carbon or full carbon/carbon units. Street derived units from others may have a higher friction matrix thats is so from cold? who knows?? but its fairly normal for the above two brands that I am experienced with.

 

Yes peter you are correct. He would slip it during his burnout and everything would be fine for the race. This is something that effects all carbon race clutchs. Once you learn how to use them you'll be fine.

 

I just had an Exedy D-core twin plate installed. I've only got about 30 miles on it, but so far I can say:

1. The install was much easier than I expected it to be, since I paid a shop to do the work

2. The chatter with the pedal depressed isn't too loud-- a little weird, but not loud. If you have poly engine mounts and diff mounts installed at the same time, like I did, it's just one more sound to add to the mix!

3. You can definitely slip the clutch. Not like the stock clutch, of course, but it's far from an on/off switch. Hell, I only stalled once on the way home from the shop, though I did have a few, er, stuttering starts

So first impressions are all positive, and I thank Rice Racing for the recommendation. Looking forward to getting it broken in, but it will probably take a while since I haven't been able to drive the car much lately.

 

We recently installed two of these clutches on customer cars, one on a fresh build with NRS 3mm ceramic seals. I've been puttering around the neighborhood to put miles on the new motor, and I must say I'm pretty impressed with the Exedy clutch from a driveability perspective

 

Hey Rice, now that its been a few years later, how is the clutch now? I want to order one for my FD3s but my car is driven daily. After talking to a Exedy Rep he told me not use it for daily street driving because on the highway the clutch will cool down to much and be worn out rather quickly if I down shift etc. What do you think? I need a twin plate to hold the torque and absorb some of the shock to the drivetrain with the sprung hub and C/F disk. What is your input about the Twin Plate Exedy D-Core Clutch now thats its been a few years later. I tried PM'ing you but for some reason it won't let me send you a PM...

Jay7...

 

I think thats because he's banned, but I could be wrong. Might have to ask elsewhere for longterm opinions.

 

That's the dumbest thing I ever heard...


-Ted

 

Exactly what I thought, but he's the Exedy Tech Rep. So I would think he would know something. I don't know what to believe, i'm trying to find someone with the clutch or Rice himself..

 

Yeah, that's the scary part...
Carbon-carbon has an extremely high heat tolerance; they do make F1 brakes out of this stuff.
In fact, we had to "dry out" out our ATS twin carbon discs, since they got soaked with trans fluid (bad seal)...by burning it with a propane torch.

If the carbon discs happen to slip due to them being "too cold", it'll just create more heat from the friction.
The more heat the carbon-carbon disc gets, the better it starts to grab.
If anything, you'll end up warping the metal (intermediate) disc(s) if anything?


-Ted

 

Very true...