Two questions. Does anyone know the correct size to cut the header pipe for this engine. Macs web site does not have this engine. Second question, what size tap to use for the pressure fitting on this muffler and where is the best place to install it. Thanks for the help (I posted this also under tips and techniques)

some guys mount the pressure fitting on the header, i mount mine right before the apex of the tuned pipe. There are two basic types of pipes you can go with... muffled(good all around performance, and pleasant sounding), and the Unmuffled pipes, AKA "nitro pipes" they are designed for top end(rpm), you'll hardly have any midrange, and they are loud.... if all you wanted was speed go with a nitro pipe, if you were going to be flying pattern or aerobatics got with a traditional muffled tuned pipe



*edit you ought to pos this in the glow engine section youll get a lot more responses