I,m interesting in this exhaust not really for speed reasons but for STOL operations, I notice that they say it increases the rpm on a fixed pitch by between 30 and 130rpm, with my plane which is rated at 180hp at 2700rpm with the fixed prop I don't get more than 2500rpm static, if this thing could deliver another 80 to 100rpm for take off I think that may make a big difference in take off distance as the published take off numbers for my model of plane with a CS prop at 2700rpm versus a FP at 2500rpm static all else being equal are quite significant.