I saw Todd Blose flying the prototype BME Ultimate with the Exteme 110 in it at a fly-in in Henderson Tx last weekend. He was using standard mufflers and a 28x10 Mezlik. I didn't tach it or anything, but it sounded like it was hitting at least 7000rpm. He said the plane weighed 28 lbs all up with smoke. He was hovering and doing torque rolls down on the deck and this thing would absolutely BLAST out when he nailed the gas.