Ok before you flame me, i know that there have been tons of discussions about flywheels so far...but this is a bit different.

I want to know which of the like 5 or 6 flywheels is the absolute lightest ONCE put in the car...as in with the counterweight also. Half of you talk about the weight with the counterweights and others without and so its kinda hard for me to compare one to another.

Ok this one is a bit in left-field.....Isnt it possible to run a car without a flywheel? how would one go about doing this?..yes i know streetability would be screwed

Also i was wondering if anyone has a video clip of revving the engine with a light flywheel.

thanks

The counterweight is essentially meaningless to the "weight" of the flywheel.

It is not how much the flywheel weighs more than it is where the weight is located. If the weight is located in the center like the counterweight, the "moment of inertia" is virtually unchanged.

The moment is effected by the mass of the wheel and its radius. removing 1 Kg of weight at the outer radius is equal to removing 4 Kg at one half the radius. The Mazdaspeed is a good example. It really doesn't weigh much less than stock, but because they drilled holes in the outer rim, it has about the half the moment of inertia as the stock flywheel.

Many of the flywheel makers will tell you how much they weigh AND how much smaller the moment of interia is versus stock. The later is by far much more important.

Anyway, just by looking at the flywheels I can't image anything having a lower inertia than the Prol-lite by ACT.

http://www.rx7.com/store/rx8/images/ACTProFlywheel_large.jpg

It is only 9.5 lbs, but more importantly there is almost nothing but air along the outer rim so the moment is going to be tiny. (No, the 9.5 lbs doesn't include the counterweight, but won't effect the moment much so it really doesn't matter.)

-Mr. Wigggles

Ok this one is a bit in left-field.....Isnt it possible to run a car without a flywheel? how would one go about doing this?..yes i know streetability would be screwed


No you can't. The clutch would have no way to engage the motor w/o a flywheel.

And did you notice those teeth on the OD?
That is what the starter engages with.
Gotta start it to drive it.

Next you need to smooth out the pulses. That was what the flyweel was originally for. The other functions just evolved because it was easy.

Check out this thread I started:

http://www.rx8club.com/showthread.php?t=40514

It does a complete comparisons of SR motorsport, Racing Beat and MazdaSpeed's flywheel....and stock weights.