ATC110 exhaust size?

[Micahdogg]

Does anyone know the diameter tubing that most aftermarket exhaust systems use? I would like to order some mandrel bends and make an exhaust system for my '79.

[oscarmayer]

i know that different years had different ID exhaust, but I can pretty much say that 1.5" tubing is going to be bigger than stock. BTW, you need to be vrey carefull NOT to do too much change size. the reason is 4-stokes need some back-pressure to operate proeprly and due to the fluid dynamics og how they operate. i owuld measure a stock pipe and just go slightly bigger. Also if your not upgrading the engine a lot then it may not be worth your time to touch it.

[Micahdogg]

Yeah, that's why I was asking. I didn't want to build something too big, but my stock system is rotting away and I just have this welder sitting here so..........

The goals are to stay under the cost of a new DG system, increase power, and do something that Shortline hasn't seen before.