I bit the bullet and bought a PTT Twin Disc Clutch. I believe it is the High Torque Metallic version (not 100% sure since it isn't here yet).

I was talking to a few people on a few different boards (and Street Surgeon) on here and there were recommendations to "upgrade" the clutch with other parts (QM discs/TMZ discs). My plan is to drive the clutch as is (since it supposedly has a ton of life on it) and then decide to upgrade it.

I was hoping I could get your guys opinions on the clutch and whether or not I should upgrade it, what to upgrade too, etc. Also, I could use your opinions on the clutch in general. I found some old threads, however, they are over 2-3 years old and I am not sure if PTT has made revisions. I also understand the engineer for PTT use to work at QM so they are very similar in functionality (outside of the .200 versus .250 disc thickness).

Also, if anyone has tips/advice/insight on how to install/setup the clutch, that would be great to hear as well. I know I will need a clutch stop and izusu slave. (I am not sure what adjustment of the finger extension is but I know Street Surgeon mentioned it).

Thanks,
Alan

P.S. I will be somewhere in the 600hp region on a Holset VGT turbo. (I assume that is around 400-500ft/lb peak)

you don't need an Izuzu slave cylinder. i'm running a FWD one in my 1g, i love the pedal feel. works just fine.

install it with the fork shimmed dead straight. use an input shaft, or buy the metal tool to align the discs. if you just bought it, you should have the revised discs, they should look like an "8-puck" the way the seperations are. i had the non revised version that looked like 6-puck in comparison, and they had plenty of life left just had spline wear on the outer one. i got the newer 8-puck style and i have no complaints. sure, its a little noisy, but it's not too bad. i have mine setup with a pedal stop, or you could just set it up with the floor as your pedal stop. the main thing is that you don't over extend the pressure plate fingers.

there is a bit of learning curve to driving it, it revs very fast and grips hard. don't try to slip it too much. it's a really nice clutch though. i love mine. i don't use a 2g accumulator either. it may chatter, make a little noise, but you will absolutely love the transmission going into whatever gear at whatever RPM!

Are you going to be daily driving the car? I had the QM/TMZ twin for a while. While the discs had plenty of life when I pulled it out, the floater and pressure plate warped and caused some uneven wear, and obviously, the parts weren't making full contact. When I ran E85 and put it on the dyno, it slipped on me just after peak spool up, just before where it would have made peak torque.

What I am saying is, daily driving is hard on the twins. I never gave the clutch a full effort pass and only launched it maybe a dozens times. I've put single disc clutches through more and they've lasted longer.

Thanks for the responses guys.

I understand the noise as I have a twin plate on my supra and honestly can live with it for the performance. I am happy to hear that you can guys didn't have to do anything that special to run it.

As for the DD part, honestly, I don't think I will be DDing the car enough where it will be a problem. I mean I do plan on driving the car on a somewhat weekly basis but not with constant shifting, driving, etc.

I'm running a regular PTT twin, stock 1g slave, PTT TOB and the 2g accumulator, which did wonders in drivability.

I'd run it as is, and not worry until something comes up. I actually love the clutch, it's very fun to drive and easy to drive.

No pdeal stop needed, or isuzu. I think that's more of a QM thing.

fonz! you finally came over to the twin disc side! when did you get your PTT? did you try it without the accumulator first?

we really need to meet up sometime soon, i'd like to get some pointers on my SD setup.

I will have to look into that accumulator. Where did you get yours from?

Also, are you sure that you don't need a stop? I have heard from multiple people that it is needed in order to avoid damage to the fingers. Also did you do finger adjustments as well?

Thanks for all the input so far!

Alan, i run mine with a pedal stop, however, you could just adjust it so that you use the floor as the pedal stop.

for mine, since i don't use the bottom clutch switch, i welded in a bar to re-inforce it, and simply threaded in a bolt and put a nut on it to lock it in place. before that, i used minimal adjustments and kept the pedal close to the floor. it didn't bother me that much, but it is a bit nicer with the pedal stop.

Yes, I've had the PTT sitting around for like 2+ years now, and never put it in because my 2600 was working so well I saw no point of dropping the trans. Stripped 3rd, trans came down and PTT went in. I bought it off some kid on CCDSM for CHEAP.

The accumulator actually came with my vr-4, in a parts bin, I believe all 2g's will have them, or you can order them new from mitsu - I don't know any numbers at the top of my head though . Basically makes the clutch more tolerable, much less of an on/off switch with it installed. Without it, it was really a bitch to drive. I put the accumulator in within 100 miles, and either that, or just breaking the clutch in more... it's very easy to drive now.

I've read of guys using pedal stops with PTT's, I tried, but didn't like it. After some adjustment I got the pedal right where I want it, with no oddities or anything that would lead me to believe I need a stop. Only time will tell I guess.

Phil, I'm down to meet up whenever. I'm no pro, but I know enough I'd say.

Sweet. I will look into a pedal stop and adjustment. I will look around craigslist to see if I can find it for cheap. If not, I think JNZ has a used one for like $25.

Did you measure finger movements or anything like that btw?

Thanks for all the tips guys!

Do not run a shim on the pivot ball with a twin disc. That's for single disc clutches where you need the throw. Twins need less throw so running a shim would not be wise.
I had a 1g slave without a pedal stop and overextended the fingers, and kept pushing hard enough to kill the thrust bearing and crankwalk my motor. I personally would never run a 1g slave on a twin ever again because of this experience. Modifying an Isuzu slave is about a 2 on a scale of 1-10 in terms of difficulty, and it has the added bonus on engaging slightly slower so the car is easier to drive, so I don't see why you wouldn't run one. I also have the 2g accumulator which slows the engagement even more which is nice.

My setup was:

PTT Twin w/ceremetallic discs, 2G accumulator, 1G awd slave cylinder, new oem master cylinder, hockey puck pedal stop, and a sh*t-load of setup/adjusting to get it just perfect so I wouldnt' over extend the fingers. I used a new oem pivot ball, no shim (of course), a billet clutch fork, no extended slave cylinder etc. The car shifted great, gripped hard, and did what it was supposed to. That being said IMO PTT clutches are whack and I'd never, ever use one again. You can upgrade the OLDER clutches to the quartermaster gear drive but it's super expensive and you would almost be better off selling what you have and just going with one of those.

What I liked about my PTT:
1. Shifted nicely
2. Gripped nicely

What I didn't like about my PTT:
1. The noise. The howl on decel was terrible, you can get used to it if you want, but everyone else will think your car is coming apart. That being said the "chatter" wasn't that bad and I wouldn't be concerned with that at all.

2. The company. It's basically Steve Fox and his wife, and if you have a difference of opinion with him good luck arguing with an engineer who's "always right" lol. His clutch is bar-none PERFECT and any fault lies solely on your install, machinist, or the inherent design of the mitsu trans itself. Hell he didn't even start heat treating his hubs (which used to wear down like CRAZY and destroy input shafts) until a bit ago?!?

3. The gimmicks. The hockey puck install, the random slaves or band-aids to get an off the shelf clutch to work etc.

4. If you're planning to drag race these clutches suck. You're not supposed to slip them at all (especially with the cerametallic discs) if you do you'll overheat and kill stuff.

5. Steve Fox told me that if I daily drove it to expect to get about 12k miles or less out of her. Awesome.

Anyways, I'd go with a Tim Zimmer heavy single clutch setup, or the Tilton carbon/carbon I already have /ubbthreads/images/graemlins/smile.gif

I took this video a little over 2 years ago. And add to what Street Surgeon said, I got about 15,000 miles out of my twin, but it like I mentioned before, I warped the plates well before the friction discs were gone.

click

What about the new quartermaster 8 leg?

Thanks for all the insight guys. I guess I might try upgrading the clutch when it goes out but until then I think I will just run it and see where it goes.

Thanks,
Alan

My experience with the PTT clutch in 431…
Clutch stop- I used washers as shims between the slave cylinder and transmission with longer slave cylinder bolts – worked great.

Now for my experience… I felt there was no clutch slip at all which made it difficult to 60ft well without breaking driveline parts. When I tried to slip the clutch – it would slip then engage fully. After breaking u-joints , two rear axles, 1 front axle and a transfer case – I gave up on learning to launch with it and went back to a regular single disk – and now auto <img src="/ubbthreads/images/graemlins/devil.gif" alt="" />. Needless to say I personally didn’t like it – however many have mastered the art of launching with it. Just keep in mind this clutch will be a stock driveline parts breaker at 600hp and full weight vr4- when launching the car. If you have upgraded axles, transfer case and driveshaft then I wouldn’t worry as much – just my experience!

Quoting Street Surgeon:


Anyways, I'd go with a Tim Zimmer heavy single clutch setup, or the Tilton carbon/carbon I already have /ubbthreads/images/graemlins/smile.gif



Love my car so much more after going from a twin disk back to a TMZ single. I will never again put a twin disk into a streetcar.

Man tons of hate on the twin disc. I have a OS Giken twin on my supra and I didn't have problems with it. I guess that is comparing apples to oranges though since they are different manufacturer.

I'm not hating, as I know they have their place. For my use on the street though with a full weight car, it was an annoying setup. I bought my twin used and got a great deal. It literally had about 200 miles on it when I got it, so it was like new. I thought it would fix some shifting issues I was having. In reality, I just needed a new, better shifting trans and new MC and SC. Now that I have new hydraulic cylinders, and a new trans with Evo3 internals, my single disk clutch disengages and shifts perfectly.

So at this point, I wouldn't really see any benefit from the use of a twin, but would still have to deal with all the annoyances. Leaving an intersection on an uphill incline, stop/go traffic, decel noises, etc...I just couldn't deal with it anymore. Maybe it's better with a lighter car, or with another platform that has twin disks available with sprung hubs and more forgiving friction pads. For me it was a complete pain in the ass. /ubbthreads/images/graemlins/dunno.gif

Alan, application is everything. if you plan on taking your car and driving it through NYC like traffic, yeah have fun with a PTT. you'll be selling it in 200 miles like the guy who sold his to wop. personally, i enjoy mine. i take the good with the bad. there isn't very much stop and go driving for me to do so it isn't a big deal. i use mine in my 1g, however that car is on a serious diet compared to my GVR4. it's awesome when you can go out for a fun drive and hammer through the gears like a mad man, shifting at whatever RPM you really want to. it just sucks for stop and go, and launching it can be tricky. i feel like i've got it down well in my application, but that would be comparing apples to oranges as well, saying as i'm comparing my experiences in a gutted 1g compared to an almost full weight GVR4. like Nelson said, if you will be launching a 600+ HP setup on a nearly full weight car, get used to breaking axles, u-joints, etc at the track until you get used to the clutch.

personally, i agree with what a lot of people said. there's also a reason that my 1g has the PTT, and my GVR4 has a single.