As an addition.
A heavy flywheel will reduce acelleration because of inertia. This can be an advantage if you do not have the traction to cope with a lot of acelleration. But in those instances you'd probably be better off using a different clutch setup or longer gearing or learn how to use the throttle better.
It is in my humble opinion plain wrong to down tune the cars acceleration potential if you can find a better solution.
Be aware that the slowdown in acceleration off the line might help there but it will slow you down in every other instance where you are accelerating.