Not really. Results are widely spread over the different forum threads. This graph might give you an idea between different exhaust systems. http://mvvs.nl/images/58ccmvvs-power.jpg

You can see that the torque of a canister is more constant and the torque of the RE2 pipe increases with the rpm. Nevertheless the differences in both torque and power is enormous. I can tell because my DL hovers my 17-1/2lbs EF Extra at 1/3 throttle on the small Vess 22A break-in prop. I hope I can get through the remaining 3/4 gallon break-in fuel today and start using the 23B on Amsoil Saber 80:1. After 3/4 gallon I already tached 7200rpm, I expect the DL to exceed 7300rpm on a synthetic gas mixture now that it is broken in. That's a lot of power!