Placing exhaust pipes

[Dreaminator]

We are thinking about running the exhaust back from hedder collectors over the frame rails ( we'll oval them there) and back outside the rails. We will bend 2 1/2 pipe, notch the bottom of the cab box a little and place the Flowmasters vertical. Has anyone else done that? If so, do the mufflers run hot enough to damage the paint? thanks for the thought.

[ChevLoRay]

I have Hooker headers, with 2.5-inch pipe from the collectors, to the 40-series mufflers, and 2.5-inch out, terminating in front of the rear tires. No X-pipe, or balance tube, although I intend to add it later. My mufflers are parallel to the pavement. Flomaster has a heat shield that you can purchase to go between the top of the muffler and the surface above it, like your cab floor or wood bed floor. I don't have it and I have benefited more from a new floor pan that doesn't have any holes in it. I have no insulation (yet), nor do I have carpet. They're also in the future.

[crazy longhorn]

If I understand the ? completely, you want to run the exhaust on the outside of the rails? How about going above the trans crossmember& then through the rails(box the area, & add a chunk of tubing tween the inner & outer rails). after you get behind the cab , there should be enough room between the frame & outer box panel to lay the muffs flat(or slightly canted)....& still keep them above the bottom of the body. If you keep the bends to a minimum at the front where its hot, you will have better flow on the system. those flowmasters do get hot, so if you are close to a wood bed floor, heat sheilds would be a good idea. good luck,crazyL

[Dreaminator]

If we go outside the rails and run pipe to up/down in/out of the flowmasters it is almost zero bends straight back to the bumper. We are trying to build as big a fuel cell as possible (about 27x27x10) and still allow a strong hitch to pull boat. I am trying to avoid exiting in front of rear tire as that is illegal in Wisconsin. I know, I know Lightnings come stock that way...but that is the law when it comes to omissions testing here.

[crazy longhorn]

ok, Im with you on that.....I had thought you were planning to bag it & "lay the body". Still, as far as the bends, behind the muffler they wont hurt your flow too much, as they are away from the heat. If you can run the "hot part of the system" with fewer bends, it will flow better. I dont think you will have too much problem standing the muffs up, but you might think about drilling a very small hole at the lowest point, in the butt end of the muffs(about 1/16") to help expell the moisture. good luck, crazyL