Only way to get flywheel hp is with engine on a stand, some that run dyno at the wheels use the percentage to estimate the flywheel hp, normal automatics loose 20-30 % hp from flywheel to the wheels with rotational mass, manuals usually 15 - 25 % with rotational mass, but with our manuals the heavy dual mass flywheel puts ours higher in the % range, makes the wheel hp on the manuals vs automatic more equal but with the flywheel does help with torque some.

That is why racers like rotary forged wheels, aluminum or carbon fiber driveshaft, aluminum flywheel etc.
Those bigger brake rotors help stopping but also increases rotational weight.

1 lbs of rotational weight equals 10 lbs of static weight.
So if you put rotary forged wheels on the back and save 10 lbs of rotational weight you can gain 100 lbs over the holidays and your car will have the same performance.
They also say that removing 10 lbs of rotational weight will remove .1 sec of 1/4.
Me I like handling