A1 Exhaust Reroute

[MatthewWBailey]

Has anyone RE-routed their exhaust upwards? After reinstalling my cooler lines I went down a rabbit hole on this existing exhaust pipe routing. I assume SS put it down there bc of the spare tire location? Trouble is, the parade watchers get a face full of exhaust as I drive at 1 mph. Might be nice to route it up and have a vertical stack, shorter line and freer flow.

I notice there may be room to route a 4" pipe below the cab cradle and starboard of the intake pipe. I'd have to have the turbo flange modified but that seems doable. I was thinking of moving the spare tire cradle down to the area where there's typically a winch on some trucks. Then the spare could just flare out horizontally with the cradle and then lower with one of those cable cranks? Just brain storming right now.

not sure if Id reuse the existing muffler. Also, does anyone know if the exhaust diameter MUST increase right after the turbo as it does with the existing 90 flange downward? I'd be changing it to go up at a 30 degree angle thru this opening in the pic below, then flanging into a muffler or pipe going left then another 90 going up. No muffler? I like free flow!

Also, why is there an exhaust gas return into the intake? Is that needed?

 

[dronsen]

 

[Ronmar]

Its not an exhaust gas return. Note how the tailpipe is crimped in where that tap is located? The tap goes into the pipe and turns down stream into the crimped area. Thats a Venturi and creates a vacuum on that line. It is connected into the middle of the particle separator module above the air filter, and when the vortice generators spin off the particulates in the airflow that vacuum sucks them out and spits them out the tailpipe.

have thought about adding a noisemaker on that port so the truck howls like a turbine when I get on the throttle

The only re-route I recall seeing, they removed the muffler and straight piped it right out the back over the rear axle.

i am thinking I am going to go that same route straight out the back. Have not decided if I will keep the muffler or not. it would allow me to transition the pipe up or down fairly easy by simply relocating the side outlet port to the rear of the can At whatever height I want though…

I am going to put my ex brake butterfly down there at the union into the muffler so I will have to remount it A few inches to the rear if I do keep it.

That diameter increase right at the turbo outlet helps drop the pressure there to enhance flow. I would not reduce it there…

 

[MatthewWBailey]

That diameter increase right at the turbo outlet helps drop the pressure there to enhance flow. I would not reduce it there…

Ok that makes sense. I'll maintain that larger diameter then. I thought that might be more than just a dimensional conversion.

Thats a Venturi and creates a vacuum on that line.

Id not have thought of that. Like a vortex separator on an old dozer? I should be able to relocate that.

 

[MatthewWBailey]

View attachment 926972

Did you run it behind the tire and up or across the tire platform ?

 

[Ronmar]

Id not have thought of that. Like a vortex separator on an old dozer? I should be able to relocate that.

If its what I am thinking of, a single director that pulls air in around the peripheral of the air filter housing and a place for dust to fall out to a catch point at the end is a common item on tractors. The one on the LMTV is a little different. It has a series of smaller high velocity vortex generators, probably more than 30, with a small swirl vane assembly(fixed stator blades) to induce a rapid spiral to throw out the particles. If you pull off the snorkel you will see all the holes. I had a pic somewhere, and can’t find it.

 

[MatthewWBailey]

If its what I am thinking of, a single director that pulls air in around the peripheral of the air filter housing and a place for dust to fall out to a catch point at the end is a common item on tractors. The one on the LMTV is a little different. It has a series of smaller high velocity vortex generators, probably more than 30, with a small swirl vane assembly(fixed stator blades) to induce a rapid spiral to throw out the particles. If you pull off the snorkel you will see all the holes. I had a pic somewhere, and can’t find it.

Will that still function in a vertical exhaust arrangement? If we're just talking bits of dust I'd expect they'd still fly up with the exhaust flow

 

[Ronmar]

If you move the tailpipe venturi to the vertical exhaust stack? I would think it should still work OK. If the vacuum flow is enough to pull the particulates horizontally across the particle separator gallery it should have no problem to eject them out the pipe as high vac is caused by high exhaust flow.

that is also something to think about. The particle separator is like a cavern with hollow stalactites and stalagmites in line with each other between floor and ceiling. each tube on the top has little angled fins that create a little tornado as the air flows down the top tube and jumps the gap to the floor tube below it. As it is spinning rapidly, it tries to throw particles out of the spinning column, to be caught by the flow flowing toward the vacuum port on the side of the canister.

not all the dirt/debris gets sucked out and can collect there. If you remove the filter cover and filter, and stuff a rag back into the pipe at the back, you can remove the snorkel and vacuum pipe on the side, flip up the flapper check on the vac port and insert a long blowgun to blow out the debris on the bottom.

i removed mine completely and was amazed at how much dirt and debris I knocked loose and blew out of it…

 

[coachgeo]

.......

i am thinking I am going to go that same route straight out the back. Have not decided if I will keep the muffler or not. it would allow me to transition the pipe up or down fairly easy by simply relocating the side outlet port to the rear of the can At whatever height I want though…

I am going to put my ex brake butterfly down there at the union into the muffler so I will have to remount it A few inches to the rear if I do keep it.
.....

Now what tya hiding from us.. Exhaust brake valve? You putting a Jake brake of some sort on your exhaust?

 

[Ronmar]

Now what tya hiding from us.. Exhaust brake valve? You putting a Jake brake of some sort on your exhaust?

I posted a vid testing a PACBRAKE PRBX valve in my shop. Nothing being hidden here I am going to put it down where the joint is located at the muffler inlet. its a little less cluttered/crowded there than up at the turbo outlet, especially considering my altered intake routing to get the air filter up above the cab.

 

[coachgeo]

I posted a vid testing a PACBRAKE PRBX valve in my shop. Nothing being hidden here I am going to put it down where the joint is located at the muffler inlet. its a little less cluttered/crowded there than up at the turbo outlet, especially considering my altered intake routing to get the air filter up above the cab.

ahhh. ok.. exhaust valve = Pakbrake this time. Yeah knew you were going that direction.. the re-wording of it threw me off is all . Got me wondering that maybe you changed your mind and were heading in a new direction.

 

[MatthewWBailey]

That diameter increase right at the turbo outlet helps drop the pressure there to enhance flow.

Now for a tougher one today. Here's a rough mock-up of the proposed exhaust route. It's a little close thru that opening. Too close? Not sure if exhaust insulation would be of benefit here. Intake pipe is 1/2" away.

with this arrangement the exhaust pipe is 48" shorter and no 24" muffler section. so less temp? The turbo flange's larger diameter is 7" closer to the turbo with only a 20degree bend instead of 90. PAC brake will need to be vertically mounted. (I cut the 90 out of the pac brake flange. The other 90 in the photo is the previous down pipe). Appreciate the feedback.

 

[MatthewWBailey]

@GeneralDisorder @Ronmar whats your thoughts on
this?

 

[Ronmar]

Have you lowered the cab on it? Does the tunnel edge clear that ex brake bracket?

 

[MatthewWBailey]

Have you lowered the cab on it? Does the tunnel edge clear that ex brake bracket?

No. Not in up position. 1st pic. I flipped it downwards and that clears. 2nd pic. Bigger problem now is the cab support rests on the pipe when the air bellows are flat, dang it. 3rd+ pic
That big cross beam is in the way. Crap

 

[MatthewWBailey]

Have you lowered the cab on it? Does the tunnel edge clear that ex brake bracket?

Dumb question: does that cross member only provide the lifting points or is it structurally critical? I see some have removed that.

Or I could just cut out this section and leave the rest. The existing member would be nice for a mast to attach the vertical exhaust pipe to.

 

[GeneralDisorder]

I would run it out the back. Delete the HUGE muffler for more space between the frame rails.

I'm not a fan of where I'm seeing that going. I get the desire for a stack, but maybe an M35A2 for parade duties would scratch that itch.... whistler turbo FTW? I know I want one for that purpose and others..... hauling firewood..... or really anything..... groceries, take-out, etc

The way I see that working is to re-make the air ride hoop with a notch for the exhaust that incorporates some type of hanger and a flex joint between the hoop and the PAC brake. And of course you will need some kind of support for the stack.

 

[Ronmar]

Dumb question: does that cross member only provide the lifting points or is it structurally critical? I see some have removed that.

Or I could just cut out this section and leave the rest. The existing member would be nice for a mast to attach the vertical exhaust pipe to.

It covers such a small segment of the frame and ties neither fore or aft into the structure anywhere to form any triangles(no triangles, no structural enhancement), I don’t see it providing any structural enhancement, in fact all the holes they put in the frame to spread out the lifting load probably weakened the frame in that area… y0u could releive it to make more room for a passage, and then build off of it to support the stack.

 

[hike]

I have avoided commenting as stacks are not desirable to my thinking. I would run it out the back as @GeneralDisorder suggested. Out the back is straight forward and functional—

 

[Ronmar]

I get the desire for a stack, but maybe an M35A2 for parade duties would scratch that itch.... whistler turbo FTW? I know I want one for that purpose and others..... hauling firewood..... or really anything..... groceries, take-out, etc

Don’t forget running over Graboids…