How much HP from a lightened pressure plate?

[Rick Lee]

I have a clutch R&R coming up and am thinking about installing lightened parts. I'll only do this, if I stumble upon a great deal. I already have my Sachs OEM G50 kit. But just in case I find an aluminum pressure plate and/or flywheel, how much HP increase will this give me? Will it wear the disc or any other parts faster? Thanks.

[911nut]

You won't gain HP using an aluminum flywheel but the engine will reach the redline quicker. You will have to use more RPM's and slip the clutch more from a standing start.

[Jamie79SC]

FWIW, while there's no more horse power, my SC felt way quicker when I installed mine. I really didn't notice that much difference re. stalling at launch, but I only did the pressure plate. I imagine there would be a noticible difference if you put in a light weight flywheel as well. YMMV

[TimT]

You get exactly 0 more hp with a lightened pressure plate/flywheel..... what you do get is a smaller MOI ( moment of inertia) of the rotating mass. The engine doesnt have to work so hard to rotate the flywheel/pressure plate so It will rev more easily, and lose revs more easily.

[jeff91C2T]

Actually this is a good question. But I think we're off track.

Common sense says the engine makes the same HP at the crank, but what about at the wheels. This is what makes the difference.

[Jim Sims]

A lightened flywheel requires less power to accelerate; it doesn't make anymore hosepower per se but it allows more horsepower to get to the wheels during acceleration. While cruising or under steady state conditions one doesn't gain much from a lightened flywheel. The lightened flywheel allows the engine to get to torque and horsepower peaks more rapidly. It is also easier on synchros as it reduces the inertia they have to deal with. The downside is degraded behavior at idle as the the flywheel has less capability to smooth out engine power pulses. I've read of some cases in which the engine idle speed had to be raised to compensate. Cheers, Jim

[marcesq]

Jim is right in as much as in some cases the chip has to be changed to alter the idle down circuit so that the car does not stall when coming down to idle.

My 1 cent.