Carl Fausett

SMTCapeCod: Your '83 Euro already has the twin-disk setup.

Jim bailey - 928 International

The single disc clutch was first fitted to the 87 S-4 it is a simpler system that is it's ONLY virtue. Does cost less as well since it does not use the intermediate plate. The Carrera GT supercar runs a triple disc ....

RyanPerrella

Carl,

Do you have a bunch of intermediate plates somewhere? If so that makes this a doable solution, although not exactly cheap. But even at full retail your at about $2000 for everything, which isnt cheap but its doable.

Of course i cant do full retail on everything, your flywheel over the hassle of the hybrid, yes. Full $800 for a mid plate.......not so much, but that maybe the case as they midplate wells are drying up.

slate blue

I have a complete twin clutch conversion setup available, it includes 84 euro flywheel, used but perfect condition, near new intermediate plate and pressure plate no wear detectable on the friction surfaces. The ring gear barely has a mark on it. There is also a throw out bearing and guide tube, slave cylinder (torn boot) and throw out arm. The two friction/clutch plates have minor wear and I measured the wear at around 0.3+ mm. According to Porsche the wear dramatically slows after the first material is worn off so I would guess that these are around 75% life remaining.

A mate of mine may buy this so he has first dibs but if not it is for sale. The intermediate plate is from an euro S as such doesn't have the Porsche timing light feature. These possibly could be added. Also I don't have the S4 timing ring but could get one if I had to, so don't include this piece in the deal as it stands.

I hope $1,000 is fair for all of these parts, if you are in the U.S shipping via seamail would be $100. Hopefully some one in Oz can put it to good use.

Greg

Carl Fausett

Ryan - the best source for good used or new intermediate plates has been 928 International for me - I cant find them anywhere else easily. Clearly, the intermediate plate is the key part to the dual-disk conversion - all the other parts are easier to locate.

IcemanG17

Jim
Any update on the tilton triple race only setup?

From the info I have found....it seems the tilton triple disc 5.5" ranges between 11.4-14.5lbs and can hold between 750-1260 ftlbs of torque...way more than needed for any NA 928.... so a 20lb clutch-flywheel assembly is possible?

John Veninger

Brian,

There were a few triple disc sets that were produced. I have on in my car.
Talk to Greg Brown

mark kibort

I think im proving that the stock early 928 dual disc system can do some hard core racing abuse and handle 420rwt and near 400 rwhp comfortably. I've got 6 race days under my belt right now, and there are no issues with the clutch or intermediate plate. Plus the dual disc system is near 25lbs vs the near 45lbs of the S4 clutch system.

mk

John Veninger

Brian,

Take to Greg.

RyanPerrella

or try 37 lbs DD vs 52lbs single disc / S4 and later

IcemanG17

John
I have a call into him.....when he gets a chance he'll work on an estimate for me....but I don't really need the stronger clutch until I get the larger motor to go with it!!!

Do you know how much your tilton + flywheel weighs? I'm guessing around 20lbs total

GregBBRD

Once we got the 928 engines up over 500rwhp, the stock components (even with stronger pressure plates) would not live for even 1 day, when used on the track. Joseph Fan ripped the lining off of 3 sets of clutch discs, in one day, at Fontana. Although it might be possible to find a lining that stays on the discs (and still releases), the main problem was that the torque was breaking the little straps that support the actual plates, both on the pressure plate and the intermediate plate. Porsche had similar problems, with their 911 clutches, starting in 1992. They superceeded the clutches, so that they had 3 (instead of 2) springs, that were shorter. F&S was apparently not able to do this, since Porsche used LUK as the supplier for these pressure plates. This worked fine until 2005, when Porsche apparently forgot what caused them to change the design. They went back to F&S pressure plates, with the longer, 2 strap design. These failed, immediately.

Mark Anderson did the original engineering on a flywheel that accepted a complete triple disc Tilton clutch, just like the ones in the Porsche Cup Cars, using stock 928 pieces that were modified for use. This eventually worked pretty good (after some initial issues, that resulted in a few DNFs). We took this design and changed it around a bit, making a complete aluminum flywheel, for use with the triple disc uber light Tilton clutches. Our "hats are off", to Mark, for his work on this project.

John, Mark, Joseph, and others are using this complete system, without any failures. The clutch is very severe and has very little ability to be slipped, making it tough to use, in a true street car. It is also fairly expensive, for the "normal" 928 guy. However, even in very small production volumes, it is cheaper than the Porsche Cup Car set-up (go figure this out...)

mark kibort

I was missing 7lbs of components. (starter ring or something) Ill have to check the picture of the set on the scales, but you get the idea. You dont do this kind of mod for the weight. You can listen to my incar and see there is no issues with gear matching or throttle blips.

The triple disc set up is very cool. I saw the pics of Mark's and it is a thing of beauty. you also loose the big lever arm in place of a hydralic set up for actuation. Looks like that might simplify removal and assembly. (that in itself could be worth the price of admission, besides the intermediate plate adjustment issues and wear problems).

I know Mark A had the dual disc for a very long time on his 420rwhp version of his race car. I think when you start pushing the 450 and higher hp range, you need to step up to the upgraded stuff. Im probably lucky im still under the limits of the enhanced pressure plate and disc set up. I wonder why Joe was tearing apart the discs? he probably exceeded the clamping force of the enhanced stock pressure plate with the 480hp and higher engine set up.
what a differenece the 928inl pressure plate was in my efforts. Without it I would be pretty lost right now!

mk

RyanPerrella

928intl pressure plate?

is there some mod they do on the 85/86 PP to increase clamping pressure?

I had previously thought i would just go with carls Aluminum flywheel, find a good mid plate and then go with a stage 1 or 2 or 3 Spec clutch kit.

what does 928intl do to their PP's?

MK you said your running a dual disc, i assume the PP your referring to is the DD variety?

mark kibort

Of course the dual disc. the single disc couldnt even handle the 290rwhp the car came with!

The pressure plate is something that 928intl had modified from a stock pressure plate. dont know how it is done, but the ring that holds the pressure fingers, is moved out giving more pressure to the discs when engaged.
I think the number i heard was 50% more pressure.

mk