[Dave80GTSi]

I've had very good success over the years with a -slightly- lightened flywheel for street car use.

Assuming that you start with a heavy steel / iron flywheel, the key is to have a light touch, removing no more than, say 20 to 25% of the weight of the OEM wheel. So, for example, if your OEM flywheel were to weigh, say, 20 pounds, you'd want to remove only around 4 to 5 pounds. This percentage does not sound like much, but it notably improves the ability for the engine to rev quickly, making the car far more fun to drive.

For this reason, I am not a fan of an aftermarket aluminum flywheel when used on a street car. The engine becomes so quick to rev then that rev matching and shifting smoothly becomes much more of a challenge.

Of course, for track use, that's an entirely different set of circumstances, and revving quickly is key. The OP did not mention whether or not the car is intended to be used on the street or on the track, so the above info should be taken with the end use under consideration.

DM