RCIGN1
So with either one of the above muffler(noise amplifier,

)) the G26 will spin 18x6 easily to 9k rpm? That is good to know.
BTW, I may have other option ie CMP airplane like 120 size Yak 54/Sukhoi/Giles 202 which are in the range of 68-72 in span. Estimate AUW are 10-12lbs with area approx 850-900in.
Even with stock muffler, will the G26 pull it vertical or Abellrc muffler is a must?