How fast ???
Speed ?...with the Rossi .61, I would look for 125-145. With a jett .90, or 1.00...I would look for 140-160...I mean...who knows.
I fly at almost 3000 ft. Alt.
Yes the intakes on mine will be "lessoned", and tapered as long and as narrow as can be....(black paint is our friend on this one)
Speed cost's money....how fast do you wanna' go ?