Hi Dale

I've Flown and tested all the engines you've listed. I settled on the APC 7.8x7 for the O.S. .25FP and LA. My T.T. GP .25 liked the APC 8x7 sport prop the best. The Brodak likes even less load. I used an APC 8x5 Sport Prop on this engine, while Dave Hull's Brodak likes the Taipan 7x6 the best. The ground RPM's for the LA, FP And T.T. were between 14,400-14,600. I've not bench run or tacked the Brodak yet, so I have no #s for that engine. Prop choice for an SSR depends somewhat on how clean your airplane is. One of the fastest combination's I ran was an modified Artesian with O.S. 25 FP with the old style APC 7.8x7. and a .315" diameter venturi with O.S. FP needle valve assembly. If your T.T. has a fairly tight pinch at TDC it should work well for you.

Regards, Les

Hi Dale, Glad to hear you are coming to Albq. Looking forward to seeing you and Linda again. Don't forget to remind me to bring out the Brisket.

Don't know much about racing, but can tell you that Double Eagle Airport is about a mile from our flying field and same elevation-hence same weather. Right now, which is about the time we would be racing, it is 82 degrees, 28% Rel Humidity, and the barometer is 30.16. Little high as we have your high pressure parked over us. Anyway, that comes out to ~8000 ft density altitude with an air density of .0602 lbs/ft-cubed and a relative density of 79%. Since you will be flying over asphalt, I figured it for 92 deg and 102 deg. Raises density altitude about 500 feet for each 10 degrees with a corresponding decrease in density and rel density.

Got the airport info from usairnet.com and the density altitude calculations from wahiduddin.net/calc. As a retarded pilot (oops, retired) you can maybe make some sense out of all this. I have been told, by oldtimers that live in the area, that you need more pitch, along with nitro, to get the same stunt run as down in the flatlands. Don't know, just know that on my stunt ships I run 6 pitch up here and 5 pitch at Tucson.

Want some fun, look up Los Alamos airport's numbers and figure it's density altitude.  Bring all those Texans with you. You have heat, we have heat and altitude. Make it more fun! See you soon.
Gary