djlyon

Hi Dar

I knew I was running with the longer Rossi tuned muffler. I was running the Rossi in this configuration just out of curiosity I didn't have the short Rossi muffler and that's why I used the Performance specialties muffler. Even though both mufflers turned a 9/6 in the mid 18s on the ground the Rossi muffler was clearly way over the top and with the PS muffler the engine was just getting on the pipe at a little over 17.5. It was on a quickie 500 and I flew it this way. It unloaded nicely in the air. I would guess speed around 140+ but who knows. The sound of the engine always fools me into thinking fast. It was clearly under proped though. It needed a racing prop at this point to make it go and make it safe. A 9/6 APC at more than 19K is not a good idea. I learned what I wanted. I also did the same thing with a TT40 PRO and the same PS muffler and prop. It only turned about 300 rpm less on the ground than the Rossi but it was giving about all it could give to get on the pipe and stay there and in the air didn' t unload like the Rossi but was still fast.
The curiosity thing was because we were debating here the speed and cost of our 428 (Q500) pylon class. Should we slow it down and make it cheaper or leave it alone. The outcome was an additional new class 426 which only allows a Jett Super Sport (detuned Q500 engine)

Denis