Learn me... ACT 4 puck clutch

So I test drove a WRX yesterday with one, and holy E36 M3 it grabs like it's time to go right now. I stalled it the first time even.

I know what a clutch is, where it's located, and basically how it works. But I have no idea what an "ACT 4 puck clutch" is vs...whatever else there is. Anyone?

Instead of a disk, there are 4 smaller disks on like an X arms out from the center. Google one up. They grab harder, as you found. My friend with a SR20DET put a 4 puck in it. I don't know the brand. When it took it apart, it had ground like 1/8" out of the flywheel, and still had clutch material left. That is, not at the rivets.

I put an ACT street disk in the RAV4. ACT said it is good for about 400 ft lbs, so that should do it.

That is a ferocious racing clutch and I'm surprised you only stalled it once if you weren't ready for it. Dr. Hess explained the 4-puck mechanism, ACT is a clutch & pressure plate manufacturer. The multi-puck setup handles heat better than the usual full-disc and applies more psi to the friction material.

Sounds like it is a solid clutch disc (no springs). That's another reason it grabs and goes.

The Rice Rod's donor car SC300 had a 6-puck in it. Holy hell that thing grabs and chirps. EVERY shift you can hear the clutch. Vrrrooooooo ER-RR-RR Vrrrooooooo

I once drove an acura with an unsprung 4 puck. I stalled it twice and almost jerked me and the owners teeth out several times. Im not a fan of them for day to day street driving.

In reply to GameboyRMH:

Only stalled the first time, but not afraid to admit the next 3 stop signs were a bit herky jerky. I told the guy I really know how to drive a manual and apologized for any whiplash. He laughed and admitted he had the same issues early on.

Sounds like it might be a good thing for rallycross, and maybe even some autocross/track days down the road.

Only one stall is pretty good. Now, go find one that' s two or three discs, in a five inch design, mounted to a flex plate instead of a flywheel. Wowsers. It explains why stock car racers spin the tires leaving the pits.

This is a six puck clutch plate.

Jerry wrote: So I test drove a WRX yesterday with one, and holy E36 M3 it grabs like it's time to go right now. I stalled it the first time even. I know what a clutch is, where it's located, and basically how it works. But I have no idea what an "ACT 4 puck clutch" is vs...whatever else there is. Anyone?

I used to have an ACT 6-puck in the RX-7. (Came with the car) I eventually got sick of the absurdly-overstrong pressure plate (it broke throwout forks/pivots with astonishing regularity) and used a stock plate. That was kinda fun, that gave me a delightfully light pedal and the difference between engaged and disengaged was about 1/2" of pedal travel. Very easy to stall if you weren't used to it, although you could get used to it fairly quickly. On dirt, it was either disengaged or tires spinning, no in-between. Another thing that annoyed me about the ACT pressure plate was that it had its internal leverage ratio changed relative to stock. You know how I said with a stock pressure plate, the difference between fully engaged and disengaged was short? With the "high performance" plate (I don't speak stage-n BS) the leverage ratio was so out of whack that I had to adjust the clutch pedal all the way up and you still had to crush carpet to shift. Bear in mind, even with that, it was still stiff enough to break clutch linkage parts regularly.

I have another ACT clutch, a lower performance fiber one (came with a core engine), and the difference in pressure plates is marked. It's a lot lighter and shorter throw, although it still breaks clutch linkage parts regularly even with reinforcement. I only use it because it is SFI rated, and I think about that sort of thing when I see how high I'm winging the engine.

I would ask pointed questions about if it has a sprung center or a solid center. If it has a solid center, budget for a replacement transmission and a different clutch. Solid center clutches destroy transmissions, they are only meant for low shock load applications like road racing. Even then the engine harmonics destroy the trans more quickly since the engine is now SOLIDLY connected to the trans gears.