Exedy Stage 4 twin disc clutch

Who has used it or is currently using it? What do you have to say about it? Love it...hate it? Why...why not?

Hopefully Billy can chime in since I believe he has extended time on this particular clutch, and a lot of others.

I want to hear about this clutch too

Hey Eric, check this thread out that was local to us, lol.

http://www.nsxprime.com/forum/showt...lutch-Kit-Acura-NSX-Pull-type?highlight=exedy


To summarize what I had previously found out about Exedy clutches,

General consensus was that Exedy's carbon clutches for the NSX were known to chatter, whereas their regular cerametallic clutches had stock-like engagement (regardless of number of discs).


Also of interesting note, on Exedy's website (which lists NSX clutches again) the HM012SD (twin-disc cerametallic) is the only clutch out of the 4 listed for NSX applications that includes Street under Suitable for Driving Styles.

Has anyone used it? I may be about to install it and replace my Exedy twin carbon and I'm curious for feedback. The exedy site shows it with the full disc flywheel but I believe it is available with their lightweight chromoly flywheel as well. The Dali site said don't even think about using it to commute but I had a hugely stiff clutch in the car when I bought it (ACT unit) and you just get used to the pedal pressure. Other than the pedal pressure, this seems like an excellent street clutch for my turbo application. It holds 405 lbft of torque at the wheels according to Exedy.

I use the twin carbon in my race car, it is noisy, but I like it, sounds like a Ducati. ....engagement is nice and the clutch grabs realy good! And for a weekend street car I would also think it is okay!

I've been driving this clutch for awhile now... It took forever to master and I usually master clutch engagement very quickly. It has the usual noise but it has a hugely abrupt engagement (instant on/off and narrow friction zone) and basically I am the only one that can drive my car now. Do not ever give your car to the valet with this clutch. It's extremely lightweight and ready to go. I would rate it a great performance clutch but a poor street clutch, and I have a high tolerance for putting up with performance parts' sacrifices. I make 400lbft of torque and it handles it no problem.. It feels like it's laughing at it and you will feel it grab HARD. It says no drag racing so I don't do hard launches.

Nero, what is your power level? Why are you
removing your twin carbon clutch?

Hey Nero, which clutch are you specifically using now?

Your previous post said you were going to replace your Exedy twin carbon. Did you change to the Exedy twin cerametallic?

I changed to the exedy twin cerametallic yes. The twin carbon I had was slipping or it didn't warm up fast enough for me. It let go on the dyno at 14lbs of boost IIRC and the same on the street. I was pushing 620whp @18lbs recently for a couple of months but I dialed it back down to 14lbs and 550whp for safety. Twin cerametallic held all of it no problem.

Thanks for the quick reply Nero.

Hmm... your experience (drive-ability) with the twin cerametallic is counter to what I had researched in the past.

One day I will eventually verify this for myself, lol.

The feedback of this clutch(twin carbon) seems continue to be a love/hate relationship and the opinion is all over the map.
GregTT has done extensive tracking in his Whipple equipped NSX and more so w/ Coz and Nick F. and they like it a lot as it was meant to be.

I took Greg's car for a spin during a club drive and purposely wanted to feel the "street" behavior of this clutch and I had no problem getting it moving w/o applying any gas on a gravel parking lot and it was stiff but not on&off. Some said the carbon disks needs to "warm up" before it will engage all the time, Billy said it works great only when its new-ish, some can't stand the clutch-in rattle but I don't mind as it is a race clutch and weights under 20lbs. so the gear change is much quicker and the engine revs more freely but I did not have to adjust my driving style much. Some said Exedy has done some WPC coating so its more "street-friendly" but this info is not verified. The oem style clutch(5&6spd) is too lazy for my taste so I want something that can excite the driving dynamics.

Their new twin organic clutch is nice but the FW is heavy compare to the twin carbon but at least is one piece chromoly.
The twin carbon is the clutch of choice for me when I am ready for the WPC/Giken massage by Nick @Applied who doesn't like this clutch FWIW.

Isn't there an Exedy triple carbon clutch that Coz was using/testing?

If you are interested in Exedy clutches, make sure you check Amazon for prices. I once saw the Exedy twin carbon direct from Amazon for only $1800!

There's a huge markup on these things.

Dave

This thread keeps switching back and forth between the cerametallic and the carbon twin disc, lol.

Thanks for your impressions Tim.

You say the flywheel on the twin organic is heavy compared to the twin carbon, but don't both twin disc clutches use the same one piece chromoly flywheel?

"All of our multi plate clutches come with a lightweight chromoly steel flywheel, and the famous purple anodized forged aluminum clutch cover."

Also you say the twin carbon is the clutch for you, are you referring to the Exedy twin carbon, or does the rest of your statement mean you will use the OS Giken twin carbon clutch?


Also, I agree with you Dave about checking Amazon for prices on Exedy clutches. That's where I will probably source one from whenever the time comes.

There is a new exedy twin organic, it's flywheel is really heavy to the detriment of performance but it's supposed to be very street able. Apparently the heavy flywheel helps mitigate the chatter which people dislike (I personally can live with that trade off just not the impossible engagement). Both the twin carbon and twin cerametallic had the same chatter.

Thanks for the clarification Nero.

Do you have a link to this new twin organic? (it's not listed on Exedy's website yet)

Sounds like reasonable logic behind the heavy flywheel's effect on both performance and chatter.

JLCoolman said:

You say the flywheel on the twin organic is heavy compared to the twin carbon, but don't both twin disc clutches use the same one piece chromoly flywheel?

"All of our multi plate clutches come with a lightweight chromoly steel flywheel, and the famous purple anodized forged aluminum clutch cover."

Also you say the twin carbon is the clutch for you, are you referring to the Exedy twin carbon, or does the rest of your statement mean you will use the OS Giken twin carbon clutch?

Click to expand...

Cody posted pix on this thread about the new twin organic. This clutch was shown at SEMA last year as a demo so the clutch cover has yet to be purpled. their website is not updated yet being such a low volume item. It does seem funny to me Exedy made quite a few clutches for our car over the years and they still trying to make one to everybody happy.
http://www.nsxprime.com/forum/showt...sk-Organic-Clutch-for-the-1991-1996-Acura-NSX

The perimeter of this FW has no slotted holes to reduce inertia compare to the twin carbon FW. I = kmr^2 so every little bit helps especially the dia. of the clutch makes the biggest difference according to the equation if you are into that kinda stuff.
The Tilton FW was slotted as well but no longer made. The Tilton pressure plate was like 7-1/2" Dia. so it really revs quick. It was like $5k (years ago) for their triple carbon and the release bearing needs a bit of work to fit as its a race style. I think Don Templeton is the only one running that clutch. Lucky dude.

Probably the lighter Exedy FW chatters more for this reason but its really not that bad IMO. Besides, how long do you clutch in for anyway. At least its made out of one piece and the pressure plate looks billet not steel.

I like the twin carbon as its the "lightest" on the market because I really want a quicker throttle response even though I will never reach their holding capacity but I don't mind the "idiosyncrasies" yet it feels streetable. My 6-spd oem feels so lazy I hate it and its not dead quiet either so I welcome the change but its gonna be a big rebuild with duel spline, wpc, Giken diff so I am still saving but can't wait.
I like an overall raw feel when I drive this car that heightens my senses as I have ABS delete, buckets seats, no stereo, AC etc. Thats what the Prius is for.

The OS Giken Twin carbon is heavy IMO but nice and smooth. I think its right around 30lbs. and you have to buy the push-clutch slave contraception separate as its an add-on. Some like it(Billy, RYU) but some can never get the adjustment correct(not sure what that means). Don't know why Giken never made a bolt-on clutch so no extra contraception is needed being a high end clutch.

Bottom line is if I am going to spend pretty money for a mod, I want to feel the difference/improvement all the time or as often as I can.

When I did my engine build and was looking for a new clutch to handle the double~ power I was looking at Exedy.

There was enough bad reviews that I lost interest and ended up with the SOS Dual Carbon. Pedal pressure is pretty much identical to the OEM.

I just wish SOS offered the Centerforce DYAD that I'm using on the GTO. Both can handle the massive power and TQ. Difference is that the DYAD has a more of an OEM smooth engagement as oppose to the more ON/OFF feel.