Originally Posted by downunder
Mini tuned pipes can give a bit of extra power but they're not tuneable so you have to select a prop that gives the revs needed for the tuning to take effect. Full length pipes though can be tuned over a wide rev range by adjusting their length for the prop you want to use. The power increase though depends on the type of pipe. Some give a reasonable increase in power and are easy to set up for sports type engines while others (with an engine designed to be run only on a pipe) give an OMG!!!
increase in power
The best type of pipe for sports use is the one with a baffle about 3/4 along the pipe, the last 1/4 of the pipe acts like a muffler.
Sorry to sound dim Downunder, but what do you mean by the baffle being 3/4along the pipe and the last 3/4 being the baffle?
A picture would be nice if possible?