Quote Originally Posted by Uncle George View Post
I disagree that a lighten fly wheel will loose torque.

A fly wheel is simply a rotating mass, it "store" energy. A heavy fly wheel is going to make the engine feel smoother, will rev up slower because you are using engine power to increase it's spinning speed. AND it will also make the engine drop rev slower because it's giving up energy as the engine try to slow it down.

So, the only situation a heavier fly wheel is going to help is launching the car off line. or in a stop and go traffic. Because the fly wheel's rotating mass is going to help engine keep it's RPM.

I have not driven a car with oem fly wheel and a lightened one, so i'm not sure how much difference the fly wheel will make.. but I have driven race car fitted with motorcycle engine =) man it's great fun - personally I think it's more fun than riding a motorcycle. (but ya, hard to launch and not get bogged down).
Yeah your right in saying the engine doesn't lose torque, as it doesn't but it's whats after the engine that counts. Dyno's don't lie. So YES you do lose torque at the wheels. Also your correct in saying that a heavier flywheel will heap launch/takeoff, but they also help keep momemtum between gear changes.