Twin disc clutches

[97TurboTalon]

I wanted to see if anybody out there has experience with twin disc clutches. Are they worth it?
I'm possibly looking at the Exedy or Devo or Greddy twin disc setup. Is one better then the other? Are they really that loud?
From what I understand, they will hold alot of power and torque and still be streetable in stop and go traffic. I did read somewhere that they can be difficult to launch on. Is this true?
Just looking for some insite from other members.

[Jason]

My only experience with twin disc clutches involved a '97 MKIV Supra. It had the Greddy/OS Geiken twin disc setup.

It sounded like a rock in a tin can. It rattled when the clutch wasn't engaged. It was mostly just annoying. Engagement was on/off. It grabbed and grabbed hard.

[Rice Killer]

I have heard good things about the Devo setup from the Galant VR4 guys and it's only $1100 for the whole setup, engauges smoothly and holds MUCHO HP. If you think about it that's not much more then a ACT2900 and Xact Flywheel. If I had to do it over again I would go with the DEVO setup for sure. :D

[JackM]

I don't like them. The added weight of the extra disk burns through synchros in a hurry. You also don't get as nice of a shift out of it. The only dual disk unit I would ever use are the small Tilton units. I believe that's the only 'true' dual disk race clutch, but it won't last on the street. If you are looking for a real race disk though, who cares about the street...

Jack

[Kibo]

We all know that "streetable" is a sliding scale--some people are more willing to put up with things that others aren't. For your setup, Shawn, I'd say a twin disc is a great choice for racing purposes. However, since nearly all twin disc setups use unsprung hubs, it's going to be noisy and engage very harshly--arguably not the best for streetability.

Some of the difficulty in launching comes from the low MOI (all of the twin disc DSM clutches I've seen are 7.25" units). A twin disc setup needs to be slipped to work well, and that takes some getting used to as well. The pedal range for modulating a twin disc is much smaller than a normal single disc sprung hub clutch. If you remember driving my 2900 with Fidanza flywheel, picture something even less forgiving. :p (On the bright side, the twin disc will have less pedal pressure.)

I could easily be talked into selling my sprung-hub street disc ACT 2900 to switch to a twin disc setup. :)

[Mr. Moose]

I have a twin disc Cusco in an car. It was set to engage at the upper end of the pedal stroke, which took a bit of getting used to. After a day of driving, it's really not something you'd give a lot of continuing thought to, and feels pretty much unconscious. Grips pretty well, though.

[dsm_gsx97]

LOL! So Shawn any updates on your new twin disk and the feel of her?

I know...I'm mean, but you have to post what happened here too....

[BlueVelocity]

LOL! So Shawn any updates on your new twin disk and the feel of her?

I know...I'm mean, but you have to post what happened here too....

ROFL! Ya, that clutch worked GREAT!

Erron S.
(what was that sound?!?)

[Kibo]

Uh-oh...so a grippy clutch resulted in tranny carnage? :(

[BlueVelocity]

Uh-oh...so a grippy clutch resulted in tranny carnage? :(


Let's just say you can hear it through -MY- in car camera. :p
(I was in the Mopar lane, Shawn in the Pepsi)

Erron S.

[97TurboTalon]

I decided on the the devotuning twin disc which is a quarter master 7.25. Really nice unit with the crmo flywheel. Devotuning has excellent customer service! I got the twin disc in Friday night with Erron and John's help.
As for weight, well it weighed just about the same as a ACT pressure plate, ACT street disk and fidanza flywheel, so no real change there.
Sound, not as loud as I thought it would be, people gave me the impression that it was going to be really loud when disengage but it's not that bad. It does sound like a tin can with bunch of rocks rolling around.
Pedal feel and disengagement, the pedal is just as lite as a stock clutch. The throw is a little different from engagement to disengagement compared to stock or single disc. About 3" of pedal movement. You can definitely feel when you hit the stopping point when pushing in the clutch. It also very noticable when you rock over the pivot between the disengagement to the engagement point.
Driving around Friday night and Saturday the clutch felt great, no problems. Full throttle, no clutch slippage. :)
Sunday was the first time I truely launched the car on the stutter box with the new clutch. 6000rpm (which I think was too high, but worked for the single disc) launch, I started to let the clutch out and felt it slipping, I let the clutch out another 1" or so and it went to fully engaged. Car lurched, then there was the really loud POP. Well, I figured it was Erron that broke since he was still sitting there and I had just staled the car so I started it up again. I tried to let out the clutch but the car died again, by this time Erron was already going down the track. Yep, it was me that broke the center diff so time for a new Sheperd Stage 4 transmission.
At this point, I really like the clutch but it's going to take some getting use too. I need practice slipping the clutch and launching on it. :D

[Kibo]

Cool, thanks for the review. :)

Steve Fox (founder of PTT) was the designer of the QM V-drive clutch that devotuning sells, so it's possible/likely that the release bearing insert he makes would work with your clutch. It sounds like you're OK with the setup as-is, though.

[JackM]

Hey, 97TurboTalon, I can build you the same unit as a Shep stage 4 for $1795.00 with the same list of parts he has. But wait, it gets better! With mine you get the EVOIII 3/4 double synchro gear set, which has a slightly shorter 3rd gear that people claim takes a couple of tenths out of your 1/4 mile times! With a my torrington 4 spider it's $360 more. I'm located in Colorado Springs. 719-243-5305

[Rice Killer]

/\ Jack does great work, I have beat the crap out of my tranny for the past two seasons. I have made at least 14 (12 sec passes) since I installed it. This season I have been running a 2900 with a street disk. The tranny has been flawless all season long, and goes into gear every shift and engages like butter. Some of you "Old school" DSM'ers will remember I broke 3 trannys in one season(2004). So you know if I beat the crap out of it and it does not break it had to be built well. :p I have always used Redline fluids in my tranny since day 1, not sure how much of a differience that makes? But I Just thought I would give you guys a FYI on Jacks quality of work. :)