i have that DVD in which the Aspec kicked asses.
the modes are the car are:
Mazdaspeed Body kits
Mazdaspeed Exhaust (the old one that adds no power)
Mazdaspeed Magesium Wheels (2000dollar a piece)
Mazdaspeed Sway bar kit
Mazdaspeed Flywheel (this really helps to bring up the power)
Mazdaspeed Suspension kit with coilover and shocks (the non adjustable one)
Mazdaspeed Sturbar (the one that has four points instead of a tower bar)
and some mazdaspeed interior acceseries (seat, carbonfiber pillors, dashboard, and door handle)
In other words, the engine stays all the same with the same amount of power. No air intake was added and the exhaust only provides less than one peak Hp.
but the flywheel increased the WHp by like 10 Hp.

btw, the rx8 apec was using 18inch Neova tires, while the s2000 was on 16 something like stock tires.