Steve which way are you measuring power? The are several ways of measuring power: One way is steady state (constant RPM) (Boneville cars, Superspeedway cars, Generators would find this method most accurate). Another method is by accelerating a given weight (typically a drum) and measuring the acceleration and then calculating the power. Another method is to specify an acceleration rate and measure the power (Superflow dynos typically do this). Another method is to simulate the RPM curve that the engine will see on say a race track and then measure the power (Ford did this for the GT40 program at LeMans). As the acceleration rate increases the rotational (and reciprical for that matter) componets become more and more important. In the above componets the lighter componet will "make" more power than a heaver componet in a dyno that is based more on acceleration. The dampner that reduces harmonics better will "make" more power than a lighter componet on a steady state (constant RPM) dyno. As an aside typically torque is measured and power is then calculated from Ppwer = Torque x Rate/ constant. Another problem I have is were all the varibles controlled on the dyno so as to make the comparision valid? Were the parts tested on the same engine? On the same dyno? was the
oil temprature the same for all tests? Like computers garbage in garbage out.