flywheel:stock or performance

[streetrod77]

I'm building a 400 hp Ford 302 for my Comet. For a hot street car with some track use, should I go with a stock flywheel or would the lighter aluminum flywheel be the best choice?

[DarkoNova]

I've heard that aluminum flywheels are too light for street cars and they don't have enough inertia to get the rpm's up. Supposedly they're best left to all out drag cars.

Hopefully someone more knowledgable can verify.

Matt

[chicane67]

That depends on a few things...

Weight of vehicle.
Transmission first gear ratio.
The differential ratio.
Clutch.
Type of driving.

I have run 12 pound flywheels in street cars without an issue... and I have also run 12 pounders in street cars that sucked hindtit. It really comes down to the combination of noted variables (listed above.)

30 is about stock. 15 is about as light as I would go anymore. There are 15 lb aluminum wheels and there are 15 lb steel wheels (SFI may be applicable at local tracks.)

Drag racing... I myself would go toward the heavier. Street/autocross/roadrace... I would definately go lighter, but, it depends on the combination of parts and its end use.

[68sixspeed]

chicane67's got it right, heavy (30-40lb) for drag use (or easy city driving); light for road race, high rpm; On my previous motor I tried both, the 15lb was nice and snappy, the motor dropped rpm nice and fast when you'd throw the clutch in; I had to relearn driving with the 33llb unit, it dropped it's 60ft times about 1/10th - but held rpm more when you'd shift. Also it was easier off the stop light with the 33lb one. hope that helps.

[andrewb70]

but held rpm more when you'd shift. ....

RPMs don't drop when you power shift....

Andrew

[68sixspeed]

RPMs don't drop when you power shift....

Andrew

but I like my tranny...

[andrewb70]

but I like my tranny...

I hear you there...LOL I don't know that I would be comfortable power shifting the ROD in my GTO. I have a dog ring T56 in my RX7, and thats a different animal.

Andrew

[streetrod77]

Well the car is light at about 3000 lbs with me. Trans 1st gear is 2.97. Rearend gear is 3.80 & I don't power shift.

[70GS455]

Lighter flywheels are ok to use with 10:1 or better overall first gear ratio. You have 11.2 so it shold be ok.

[streetrod77]

Thanks for the info. Flywheel & clutch kit will come in today. This weekend will be a little busy with the Super Chevy Show & putting the 5 speed in the car for the 1st time. Wish me luck for no headaches.