Thought I would post another one, both for the Rotary guys, and those who still have not "seen the light" and still race pistons.

Doing the 7 or 8 Pro7 engines this year, and having spent a LOT of my own time on the dyno, it has confirmed what I believed. With a "stock" 12A (Pro7 or ITA RX7), assembled correctly (correct tolerances), with enough new parts, THERE IS NO POWER DIFFERENCE IN THE ENGINES !! -- ALL of the power gains are in the tuning (read jets and timing) of the engines !!! EVERY engine we have dynoed wanted different jets !!!, and timing can be a little different. I have no real explanation for this, and am still being suprised. The one currently on the dyno (#9?) may be the first one to duplicate a jetting combo (looks to be the same as #3? engine). Power gains with jetting ONLY can be impressive. For instance, I have seen gains of up to 30hp at 8k and 8.5k from the jetting the customer was previously using !!!

And we carry an air density gauge with us at the track, and we DO change jets by what it says, and we DO see a difference in power/lap times.