Looking for the correct tuned pipe for my .91fx. I was looking at Macs and they have a 10mp for .61 and a 15mp for .91-1.20
When I look at the tuning info they have I see that they are tuning the .61's at 14,500rpm with the 10mp and the 1.20's at 10,500 with the 15mp.
So if I put the 10mp on my .91 it should tune at 9,700 and the 15mp should tune at 13,800. If I want to use a larger prop and tune my motor for grunt I would think that I should use the 10mp pipe. Right now the motor turns a 15 x 6 apc 10,500 with stock muffler and removed baffle and 11,700 with an Ultra thrust. I would hope that if I used the 10mp tuned with gradual back angle I would be able to run a 16 x 6 or 16 x5 close to the 10,000 rpm range. I have been trying to learn about pipes so someone that knows them please advise me if I am thinking correctly.