Originally posted by holycowSVTpaul:

A lighter flywheel/damper in theory should only let an engine rev faster/freer. It should not affect HP, but will have a perceived HP increase at the track because the car will accelerate faster by reaching peak power quicker.



Elsewhere in the article, the author addresses this very issue. Rotating mass does affect how much hp is delivered through the wheels. Not crank hp, of course. According to the author, all hp is generated at the top of the piston, and "it's all downhill from there." Reciprocating weight within the crankcase, rotating mass further on, as well as friction, all absorb energy, and thus hp. How much of your torque is used up accelerating the flywheel's mass? There is both a linear (in the direction of the car's travel) and rotational element to this.

Given a choice between shaving weight and adding crank hp, this author would choose the former.

Function before fashion. '96 Contour SE "Toss the Contour into a corner, and it's as easy to catch as a softball thrown by a preschooler." -Edmunds, 1998