i just got a macs 2.5cc tuned pipe for my lil 15. engine i and running it thru the hull and out the back i have to drill a hole in the very top of the back hull my question is with the heat from the tuned pipe melt the plactic hull? its abs fuel resistant hull if so any sugestions like heat sink tape around the pipe ?
not yet its a 2.5cc pipe so it should be right for the 15 i just ned to know when i drill the hole to have the pipe stick out would it melt the abs plastic and is there sumthin u can put to keep it from melting?
Not quite! The pipes come long from Mac's, they have to be shortened. Yes, you need to get air into that hull as with the lid on they don't get enough in the stcok configuration. much less with a metal pipe.
Basicly it goes like this- a shorter pipe length will boost the engine at a higher RPM. But if you get to short, the supercharge effect won't work. To long of a pipe will "tune" the pipe's supercharge effect at a lower RPM which may not be the full potential of the motor. Just the "right" pipe length will reach good top end horsepower (RPM) as well as retain some throttleability. The pipe's length is usually measured like this- from the very center of the engine's cylinder, measure through the exhaust port and follow along the center of the header, to the point of the pipe's largest diameter or center weld (not to the end of the pipe!). That's your "pipe length". You cut length off at the big hole end of the pipe, not the small hole end. You may want to cut some of the header as well as some of the pipe off instead of just cutting the pipe. You reach a point on the pipe where the diameter starts expanding, you dont want to cut past that point. Better yet, leave 1/4" or more of length before the pipes point of expansion to give the pipe's coupler tube a level area to grab on to. But you might need to go shorter still if the header is long. You can cut some off the header side to get even shorter. Ultimately you have to experiment to find the optimum pipe length. I'd say for your setup, it's safe to start around 8.25" pipe length and shorten as needed in 1/4" or 1/8" intervals. That mac pipe doesn't have a weld line on it. Mines at 7.5" to the widest part of the pipe's belly measured "my way", and I'm gonna cut it shorter. Every boat is a little different, and different people measure pipes their own ways and may give different measurements. Anyhow, the shorter, the faster... to a certain point, if you get it to short, then the performance will suffer.
im going to start with a 1" cut on the pipe better lil bit then to much i cant really cut the header becuse its the team associated tc3 side manifold with a 90 degree bend coming out thend s 180 degree bend around and it fits perfectly around my radio box
