ptuomov

A related question (partial apology for a partial hijack): Has anyone broken a five-speed box in acceleration when the box temperature was low? The usual transmission failure (not necessarily for 928, I don't know about 928 transmission, I am asking) is related to the case being aluminum and gears steel. When the box gets hot, the aluminum case expands more than the gears, causing the axels and gears to pull away from each other. This will then make the gears vulnerable. Then, all one needs to do is to catch some air in acceleration with slicks, engine revs up a bit, slicks land and stick to the ground and "vulnerability" is exposed.

I am wondering if I can keep the aluminum case cool, maybe the 5-speed can take a bit more torque? The Spec 3+ has a stated (don't know if I should believe them) torque limit of 750 ft-lbs, which I think is probably higher than the transmissions limit. I agree that it would be better if the tires would lose traction first, then clutch slip, and the transmission would have the highest limit.

hacker-pschorr

When it's time to upgrade the clutch in my 81, I'll be talking to Mike Simard:

http://simardracing.com/Flywheel.html

ptuomov

Mine is single disc, so my findings on the product may not apply. The comments on their customer service do.

John Veninger

Yes, but it was the diff spider shafts that shattered.

123quattro

I have a 6 puck sprung hub clutch in my Audi. Take-up is interesting. It's not a switch like a multi-disk race clutch, but it doesn't slip a lot. You have to let it out when you are on the gas and do it kind of quick, but it's manageable. It's a single 9.5" rated to 550 ft-lbs with their pressure plate.

My truck has a Spec 3+ in it. It feels like a stock clutch to me.

RKD in OKC

Put a Spec 3+ with solid puck in my 944 Turbo with 400 rwhp. Once broke in it was almost manageable most of the time, but every once in a while it was a real buckin bronco. It was most troublesome when trying to inch along in traffic, parking lots, and the drive thru. I wanted to downgrade.

AO

I have the 3+ in my car. I'm sure you've read my posts from previous threads, but I'll throw it out there anyway for convenience.

Installation was a breeze. The bearing they supplied with my kit was for use with the GT clutch fork, so if you do order one from SPEC and you've already upgraded to the GTS clutch fork, bearing, and guide tube, order one for a GTS. Luckily I still had my old clutch fork. However, that bearing lasted only a year and almost fell apart. I went back to my old clutch setup and grabbed the GTS bearing, fork, and tube off it and re-installed. Works great.

As for bedding. It sucked. Seemed to take forever. I was at the point of taking it out and figuring out a different solution. But then I got caught in Chicago rush-hour/construction traffic for two hours. Oh the horror! Kept stalling the engine because I couldn't slip it. I was friggen pissed. This went on for at least an hour, maybe two. Then it was like someone flipped a switch and all was well in clutch-land. It would still chatter in reverse, and still does occasionally, but it is now very streetable. The only thing is that it chirps as I feather it. Nature of the beast, I guess, but at least it's a smooth launch and more importantly, it can handle the power.