# Steel vs Aluminum Flywheel



## JimmyFox (Dec 13, 2010)

Aluminum flywheels are lighter which I would assume is better for performance.
I've also heard that if you have a heavy car (GTO) that you want a steel flywheel. Could someone clear this up please?


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## bullet20cc (Apr 4, 2009)

*flywheel*

I have a 455 550 hp. I talked to Mr. Pontiac Jim Butler. He said with that much hp run a steel flywheel. He said a stock alum flywheel would scatter the first time you hammered it. I'm sure there are aftermarket alum or alum alloy heat treated to a T8 that would work but it has to be solid. No lightening holes.
They have a 64 tempest that ran 228 mph in a 1/4.


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## dstryr (Aug 27, 2007)

I have the understanding that if your engine can recover quickly from the RPM drop at the hit and gear changes then the aluminum will be quicker. But if your specific combination needs the inertia of a heavy wheel then it will run more consistent and not bog on a launch unless your RPMs are way up there. Lighter car and taller gear => alum/lighter, heavy car and lower gear => steel/heavier.

Here's a good article, flywheel discussion is a ways down.

http://www.popularhotrodding.com/features/0602phr_engine_drivetrain_rear_wheels_power_increase/index.html


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## KyleGT05usmc (Feb 28, 2009)

Maybe if you're running Nurburgring everyday you could benefit from the lightweight flywheel. 

until then stick with the heavier. the lightwgt is too light and has tons of clutch shutter in daily driving. and no real benefits of holding rpms between shifts that i noticed. 

also you have to think about how heavy the car is, by reducing the rotating mass(by going LW flywheel) you're going to hinder yourself in low end torque. thus more rpms will be required to move the car from the start. i had to start at about 2k RPM from a stop just to avoid clutch shutter. i went back to steel and ill never go lightweight again.


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