Exhaust routing

[Justin]

As I'm getting closer to finishing up the suspension and steering, I'm planning the next step of my build-exhaust. I'm switching from a dual 2.25" to a single 3" on the passenger side with the rear outlet behind the wheel, possibly through the body. The main goal is to have it tucked up away from rocks. Anything I need to take into account? Any place that's better to run the crossover from the driver's side header to the 3" section? I am planning to run a single cat after the junction, and I'm not sure if running the crossover near the transfer case will get it hot enough to function properly. Maybe dual cats would be better? Anyway, any ideas would be appreciated.

[Dukietown]

I would think you could do a cross-over y pipe with the cat right behind the collector. Something like



Is there room to run the crossover between the trans and transfer?

[Justin]

That's pretty much the setup I'm thinking of. I'm not sure about running it between the trans and transfer. I haven't gotten the front driveshaft in yet to check clearances with the high pinion diff. I'm assuming it won't make a huge difference at the t-case side, but....

[ZOSO]

Mines got a y pipe like that that takes the 2.25" into 3" When I crawl under it next(tomorrow) I'll snap a pic.

[landshark]

I would think you could do a cross-over y pipe with the cat right behind the collector. Something like



Is there room to run the crossover between the trans and transfer?

Exhaust shop did that very thing with my 76. Its tucked very close up underneath between the c4 and engine. No problems with heat

[ZOSO]

[Justin]

Rob, any problems with clearance out on the rocks? I've smacked my t-case a couple of time, and yours looks like it hangs down lower.

[ZOSO]

No issues yet. It doesn't hang much lower than the tcase. I haven't put the skid plate back on yet but i dont think it's even an inch lower than the skid plate.

[Gunnibronco]

Mine drops down and crosses just behind the oil drain plug. It was the first thing my hp diff hit, before I moved the axle forward. The exhaust isn't installed now, so I don't know how it all fits together (or take better pics). I think I'll gain some extra clearance, how much remains to be seen. That said, the exhaust could be tucked up better in that spot, and was something I wasn't really happy about. It might get changed.

Here is the best pic I can find, from just after it was installed.

[Justin]

Rob, thanks, that may be how I end up routing it. Chad, what headers are you running? I traded those axles I had for sale for a set of 3/4 length Hooker headers. They're a great compromise, but I'm not sure they're short enough to do it the way you've got yours set up.

[Gunnibronco]

Mine are the BC Broncos shorties.

I thought exhaust was something best left to a shop. Then I saw the results of a self built exhaust from a mandrel bent kit, like this:

http://www.mandrel-bends.com/catalog/bu ... a7bc950d7a

It was on a Chevy hot rod truck.

I'm sure its something you could pull off yourself, with the tools you have at your disposal.

If I have to change mine (which is likely- I have no idea how it will fit with the ZF/Atlas, and I might want to change it for axle clearance) I'm hoping to just get some pieces & modify it to fit.

[Justin]

That's the plan-they carry b-stock, which is apparently pretty much perfect. I may still wind up going with the BC shorties. The more I look at it the more I want to go under the trans behind the bellhousing, but I'm not sure how much the heat will impact the trans. It's an NP435, so not as critical as an auto. The other thing I might try is going with dual cats right after the collector, then have the pipes meet up behind the transfer case. I've got a 2" body lift, so I should be able to go over the rear drive shaft. I think...

[ZOSO]

If your worried about heat wrap the exhaust.

[Justin]

Thought about ceramic coating as well.

[Gunnibronco]

http://store.secondskinaudio.com/therma ... ps-2-pack/

This stuff is pricey, but could be applied to the bottom of the floor, just where necessary.

[Jesus_man]

See the last few pics on this page for how mine is done:
http://s8.photobucket.com/user/jesus_ma ... t=2&page=2

I don't recall all the thought that went into what I did, but I remember my options being very limited. I had to come off the driver side header, wrap nearly 180* towards the front, and route it under the oil pan and down the passenger side. But it's all tucked up above the bottom of the frame. I kinda wish I put a cat on it, but all I have is a moroso spiral flow muffler. It sounds great, maybe a little raspy on the higher RPM's for my taste, but I don't usually have it wrapped out. I believe I have factory Mustang Shorty headers.

I do get too much heat transfer from the exhaust joint on the passenger side into my Ballistic joint causing it to squeak. There's no room for a shield in there, although I tried. I did end up wrapping the exhaust in that area. I think it helps slow the heat transfer down.

A great source for wrap is:
http://www.siliconeintakes.com/dsm-intercooler-piping/

They are in the 'Springs and the cheapest I found. Maybe order up your CAT(s) too!

[ZOSO]

See the last few pics on this page for how mine is done:
http://s8.photobucket.com/user/jesus_ma ... t=2&page=2

I don't recall all the thought that went into what I did, but I remember my options being very limited. I had to come off the driver side header, wrap nearly 180* towards the front, and route it under the oil pan and down the passenger side. But it's all tucked up above the bottom of the frame. I kinda wish I put a cat on it, but all I have is a moroso spiral flow muffler. It sounds great, maybe a little raspy on the higher RPM's for my taste, but I don't usually have it wrapped out. I believe I have factory Mustang Shorty headers.

I do get too much heat transfer from the exhaust joint on the passenger side into my Ballistic joint causing it to squeak. There's no room for a shield in there, although I tried. I did end up wrapping the exhaust in that area. I think it helps slow the heat transfer down.

A great source for wrap is:
http://www.siliconeintakes.com/dsm-intercooler-piping/

They are in the 'Springs and the cheapest I found. Maybe order up your CAT(s) too!

Looks like the same as ANfittingsdirect.com. Cheapest place I have found braided lines and fittings.

[Rox Crusher]

Justin, I run a single CAT and really like it in terms of cleaning up the exhaust smell, etc.

Mine is kind of close to the floor board and gets pretty hot. So hot that I need to ad a shield to deflect some of the heat away from the floor board.

The 76/77 models came with one which bolted into the frame.

[Justin]

JD, your link is broken, would love to see your setup. Jeff, how is your crossover routed?

[Jesus_man]

Must have something to do with a link from my account to which I am signed in vs not. But here's the pics:

Drivers side:


Passenger side:


2 into 1 just beside the tranny:


Looking forward from the rear:


Certainly not the prettiest work, but it does what it needs to.

Don't forget I got a nice piece to finish the hole thru the body if you're so inclined.

[Rox Crusher]

I'll get a couple pics for you on Thursday.

[Justin]

Cool, thanks!

[Digger]

Mine are the BC Broncos shorties.

I thought exhaust was something best left to a shop. Then I saw the results of a self built exhaust from a mandrel bent kit, like this:

http://www.mandrel-bends.com/catalog/bu ... a7bc950d7a

Thanks for the link! That is exactly what I needed for doing my exhaust.