John,

Ribs are at about 90-95% and I will be racing this summer.

Randy and John's numbers-

187mph in a dive would be around 22.5K with the 8.75 prop.

Years ago in F1, Gary Hover showed up with an audio tach at a Phoenix race. On the ground he was propped to turn 22K. In the air, it would only pick up the engine noise when flying away from the pilot. The airborne rpm was also 22K, but when you do the math from your friendly physics book (the section on Doppler efect), I was able to calculate that the engine was turning around 27K in the air. I relayed that information to Henry who didn't believe that engines unloaded that much. (Back then you had a monthly talk to the piston and sleeve supplier.) Over the phone, I heard, Clunk (sound of a heavy dusty book htting the desk), flip, flip, flip (pages turning), click, click.......click (HP calculator), "Hmmmmm, you're right! Wow!"

Of course, an open exhaust engine can turn up to whatever. With the magic muffler style pipe, there is a hint of lock-in to limit the upper RPM. With any engine/prop combination there is a horsepower curve. Your airplane's top speed is related to the power and drag by a cubic function. Diving just converts potential energy back to kinetic. Want to go faster in a dive? Pitch up the prop, fly richer, and add weight to the airplane.

I always thought that Vecter ad claiming 208 mph was a real disservice (knowing it was also completely meaningless BS).

Fred's dive would have increased the rod loads by about 50% (a guess), it would take a few hours to dig out the books for a true analysis.

Now for a common myth - people seem to be confused by prop efficiency and prop slippage. Prop efficiency is a measurement of how much engine hp gets converted to power actually dragging the airframe. It usually runs around 80-85%. So say your quickiie engine has 2.8 hp (this hp is not static, it's on a curve related to rpm) and the prop efficiency is 82%. All this means is that the airplanes speed is related (cubic function) to it's drag when it is absorbing 2.3 hp. So picking the correct prop is finding the right pitch for the day where the engine is peaking on the curve for the airspeed. Where a lot of people seem to go wrong here is they think the 82% figure is a measurement of prop slippage. Of course, for real entertainment read the extreme section where warp drive is just on the horizon.