First off, sorry for all the questions in my posts. I'm going to try and help any way that I can. I have 2 inch ID sleeved holes in my frame for 1.5 or 1.75 tubing. If 1.5 is enough for a stock motor, I will run it for the fact that it leaves a tit more room. My problem is everyone thinks if we hard mount it (drill and tap the frame and bolt through the rubber hanger) that it will break something. I keep telling them to put flex pipe the first bit right after the collector and they still think it will break. First shop (and only shop) took it upon themselves to royally I'm gay the whole deal up. They literally layed the pipe in the holes, welded a hanger to the floor and then just let the muffler hang with no support.


Here are pictures of my frame...







Here it is with everything mounted...

 

i would think if you would make a dual hanger right around the sleeve with 2 seperate rubber hangers, it would keep it from rocking back and forth and hitting in there. Then hang the muffler right after the sleeve and just dump it right there. other that that i don't see why a flex pipe and hanging kinda like stock pipes would hurt it

 

kinda what I was thinking as well. I think if I hung it off the cab floor, and then also off the lip of the bed floor we left it would be fine. Sadly the shop I had it done at is clearly not so "creative". maybe a double hanger at the firts hoop, then one right before the cab ends, then one as soon after that the bed allows.

Anyone else see a problem why flex pipe wouldnt work? Does it not allow enough flex?

 

if your going to use flex pipe, use the braided kind, like the type found in honda's.



i would solve the need for flex with polyurethane eng mounts, or even hard mounts.

and use the 1.75 exhaust. 1.5 might be a lil on the small side iirc 1.75 is oem.



then i would use a double hanger attached to the frame on either side of the holes, side to side, not front n back. the cab may move around a bit, or transmit vibration, the motor is mounted to the frame and so should the exhaust.

 

where would you put the flex pipe? the down pipe goes up under the floor, so it would be super short and possibly too tall. I may just have to try it and see. Seth mentioned a good point on twistedminis, the stock exhaust is just bent, if i piece together 1 5/8 tubing that was mandrel bent I would still get better flow. I'm almost positive you can get it in carbon steel as well so I could weld it.

 

i would use flex pipe as a last resort.


in that scenario i would have to weld the exhaust to the frame through the holes, and i would use the flex to connect the down pipe to the welded to frame part.


but now that i think about it, theres not many snow flakes in hell. so i think your going to vibrate through the holes if the exhaust tube can move at all.



i now change my vote to using a braided flex pipe and welding the rear section of the exhaust to the frame, F hangers.

 

Side dump

With your 4 link, frame work, fuel tank, and all the plumbing for your bag set up, I would try to route your exhaust away from all that stuff to keep it away from all the moving parts. You running a header or the stock down pipe? Is there going to be a catalytic converter? I would take a hot rod or truggy style exhaust and work it in to all your custom metal work you have going. After the down pipe and the collector and cat (still under the cab) I would go with a small, compact Flowmaster muffler (now just under the beginning of the bed) and have it dump out the side of the truck before the tire. If you have it dump out underneath the truck it will resonate under the bed and you'll have to listen to that constantly. I always thought it would look cool to cut in to the body section of the bed in front of the rear fender well and have the exhaust come at maybe a 45 before the exterior of the truck and have the hole and exhaust tip follow the body lines of the truck. Kinda like how the exhaust dumps out through the side skirt the some Mustang's. Just a thought...

 

typically how hot does the exhaust pipes get a bit after the header? reason I ask is I have an idea as to get this to work but it requires incorperating the frame rail and i'd rather not ruin my por15...

 

how close do you have the floor boards to the top of the rail? can you fit a little more pipe? i ask because, i would have used a larger hole through the frame to run 2-2.5" pipe. and run a muffler once you are out from under the cab. or like was said, have the motor mounts be solid and have a short flex pipe section from the header to a stub coming off the first hole, then tube welded from the first to the second, a stub off the second with the muffler, and one hanger for that. if that makes sence.