BJ74 exhaust info

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widewestcruiser

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Summerland,BC
I'm planning on having a new exhaust system installed, 2 1/2 inch aluminiumized pipe with a free flowing muffler. I understand this can be routed inside the rail, but really can't see how this is possible. Does anyone have pictures of this installation. How does the 2 1/2 inch pipe from the manifold get installed, just cut the old pipe off and weld the new pipe over top, as most muffler places do, or have a new flange made up? Where is the best place to exit the tail pipe>

Thanks for any help.
 
do a search and you will see how the exhaust shop i used accomplished it...i do nto have time right now to search for you...

you go under the driveshaft in front of the cross member about 3/4" in front and allow for driveshaft drop under full extension (roughly 2" below the driveshaft)...
at first i was concerned about crunching hte exhaust but after 4 years of doing this on my wheeling rigs i have yet to crunch any...as well as my customers.. and some of them are not... how do i say... gentle ... on their rides...
 
widewestcruiser said:
I'm planning on having a new exhaust system installed, 2 1/2 inch aluminiumized pipe with a free flowing muffler. I understand this can be routed inside the rail, but really can't see how this is possible. Does anyone have pictures of this installation. How does the 2 1/2 inch pipe from the manifold get installed, just cut the old pipe off and weld the new pipe over top, as most muffler places do, or have a new flange made up? Where is the best place to exit the tail pipe>

Thanks for any help.
Click to expand...

If your old flange is good ,then welding it will be ok.

I routed my 1HZ exhaust as per factory from an exhaust book(I have never seen a HZJ73 )
I had the piece behind the t/case made removable with a section held in place with 2 u/bolts in case I wanted to do work in there.
It was then joined onto my old 3F tail pipe and sports muffler to exit the LH side.
Its not the most direct exhaust but Im getting full HP.

I cant see the point of running the exhaust along the inside rail if you like space to work in. I also like to dissipate the heat from the exhaust as much as possible
robs pics 115 (Small).webp
robs pics 118 (Small).webp
 
Thanks for the pictures and info. The idea is to run the pipe inside the rails for protection and easier mounting of the sliders. This said, Crushers claims that he has yet to crunch the exhaust pipe passing under the driveshaft. I'm not sure which way is better. I was thinking of running it straight along the outside rail and exit it in front of the rear tire, just a pipe, no muffler or flex piece.
thanks again for your help
 
I did mine inside the rail. I took mine in to a reputable shop and I told them it might be tight. He looked and said that was pleanty of room. Boom. ran it straight down ran it between the case and rail and then out the back following the factory path. None of those funky bends under the ds to the other side or under the frame rail then back in. Thats half the reason to go custom to get it right like it should be and how you want it.
 
widewestcruiser said:
Thanks for the pictures and info. The idea is to run the pipe inside the rails for protection and easier mounting of the sliders. This said, Crushers claims that he has yet to crunch the exhaust pipe passing under the driveshaft. I'm not sure which way is better. I was thinking of running it straight along the outside rail and exit it in front of the rear tire, just a pipe, no muffler or flex piece.
thanks again for your help
Click to expand...

My BJ74 had the crushers style exhaust until I did the springover and didn't have enough room for the driveshaft to droop. I had it redone with the same routing but over the driveshaft. I'll be pulling it out sometime to replace it with a 3" If you can wait I'll sell it for a good price. It has a flex piece and a free flowing muffler and dumps out the left side.
 
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is your a vacumm shift t/case or manual? if it is vacumm i would love to see the pics, if it is manual then i have done the same in the past...

the vacumm changes the routing.

cheers

wesintl said:
I did mine inside the rail. I took mine in to a reputable shop and I told them it might be tight. He looked and said that was pleanty of room. Boom. ran it straight down ran it between the case and rail and then out the back following the factory path. None of those funky bends under the ds to the other side or under the frame rail then back in. Thats half the reason to go custom to get it right like it should be and how you want it.
Click to expand...
 
Thanks again for all th info.
I checked again and there is not enough space between the rail and vacuum shifter for a 2 1/2 pipe.
Please correct me if I'm wrong, but does the crushers style installation not bring the pipe parallel and below the crossmember, which could lead to possible damage to the manifold if hung up on a rock or stump. When I look under there I see all kinds of dents and bents to the skid and cross member.
Maybe it's just me and my driving habits, or I'm missing something.
Finally this brings me back to th original layout which is the only solution I can see without a body lift.
Thanks Lowenbrau, but I guess that exhaust won't work for me.
 
if you are worried about damage to the manifold then fashion up a skid plate that mounts to the crossmember, clear the pipe by 3/4" to 1" and you are good to go...

cheers
 
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