986 2.5 underdrive pulley dyno graph

[Jake Raby]

Continually we see exactly 12-15% variations between either of my engine dynos with the same engine installed into the vehicle and evaluated on our dyno-jet chassis dyno. This is the same differentials with either air-cooled or water cooled Porsches.

I am less concerned with actual peak numbers than most any person you'll meet. Our dynos were bought to be developmental tools so repeatability trumps any peak number.. Last week I did 5 runs back to back on the dyno jet and attained less than .75 HP of differential across the entire average RPM range. That repeatability is whats necessary to do the level of developmental comparison that I am interested in.