Jimbo, what prop are you going to use? I've been trying to find low pitch 10" props and they are not available, except for APC. I've tried the 10x4s, and with a light airframe, and most 25s, the speed will approach what we are flying now.

A thick wing might help, but will not slow it down enough to fall into the 40-45 MPH area. A 10x4 prop turning 15K has a speed potential of about 60MPH. My Flippin Disk, with a thick foam airfoil and 3 pounds with a GMS .25 and 10X4 MA prop will probably approach 50/55 MPH, in level flight, possibly more.

I hope you find the right combination, but history has proven in Pylon and Combat, if an engine/prop has the potential to achieve a given top speed, some dudes will be fudging enough to reach this speed. This puts a big burden on the CD to attempt to enforce what is mandated for equipment.

I have no doubts it is possible, but Probable,Hmmmm

This is what happened to Open B. The founders never envisioned the possibility of someone flying a 2.5 lb plane with a Jett .30 engine at 100 MPH. But it happened and it was legal by the rules.

Good Luck.

Cajun