Mike,
Again, the AMA site, which claims to present present rules, still shows NiCad only for the electric CL Speed classes. I am right at the "assemble the battery pack" phase of building my new B Speed ship and guess I'll have to call AMA and try to find someone to clarify the situation.
As background, my present setup uses 18 1100Ma SCR cells to drive an Aveox 1415/2Y BDC motor thru an early commutation module, which has proven to be the weak link in the system. The flight prop is a wood 8/8 Tornado copy and turns about 20500 RPM early in the flight. (This prop would wipe out the FETs in the commutation module unless unloaded in flight, as I learned to my cost.) The weight comes in at 59.5 Oz, and 8-inches of prop diameter are necessary to match aircraft drag and provide for reasonable acceleration on the dolly. 8-inch pitch is a perfect match to motor loading. I don't have my notes within reach, so estimate that, using a cut-down prop for static testing, this RPM draws about 86 Amp. Early laps are about 125MPH, with the 7-lap AMA record 119.63 MPH.
The switch to other than NiCads (I have to buy new cells anyway, for a competition battery, since the NiCads I'm now working with are the best of my old ones, to make a battery for flight testing and early contests)
I'm open to suggestions re new cell types for this application, to duplicate an unpushed 18 cell NiCad battery (I time it out after 36 seconds) to use the same commutation module or alternativly, with a new module, the maximum that can be packed into a 30-32 Oz battery.
Will Stewart