BJ73 3B Exhaust Routing (1 Viewer)

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My '89 BJ73 w/ 3B came to me with a side pipe exhaust setup and it's WAY too loud. I've had enough! I will be taking it in to an exhaust shop to bring it back closer to the stock configuration.

Can anyone share a picture which shows how the stock exhaust was originally routed? An undercarriage shot would be awesome. The diagram below is tough to interpret without good references to the body.

1606855541774.png


I'm also open to suggestions as to what works best with these 73's, though I do like the idea of sticking to how things were originally engineered by Toyota.
 
17410: Comes down from the exhaust manifold on the RH side of the truck. Comes down by the front frame and arches back a bit.

17420: Connects to the down pipe goes back a little bit and then takes a sharp left up and over the transfer case rear output and angles towards the back LH corner of the truck.

17430: Attaches roughly about 2" behind the transfer case rear output and then goes diagonally back until it gets to the frame and then dumps out behind the rear tire.

There are heat shields all across the bottom of the truck that show you the rough direction of the piping.
 
17410: Comes down from the exhaust manifold on the RH side of the truck. Comes down by the front frame and arches back a bit.

17420: Connects to the down pipe goes back a little bit and then takes a sharp left up and over the transfer case rear output and angles towards the back LH corner of the truck.

17430: Attaches roughly about 2" behind the transfer case rear output and then goes diagonally back until it gets to the frame and then dumps out behind the rear tire.

There are heat shields all across the bottom of the truck that show you the rough direction of the piping.

Thanks @Onur , this helps big time! What I really wasn't noticing / seeing was the sharp left and crossover to the driver's side. I'll make sure to look out for those heat shields next time I'm under the truck, too.
 
Thanks @Onur , this helps big time! What I really wasn't noticing / seeing was the sharp left and crossover to the driver's side. I'll make sure to look out for those heat shields next time I'm under the truck, too.
I'll get down to my garage later the day. Will take some pics for you.
 
Herr we go..
From engine RH through the wheel housing to a flex tube...
.. a bit parallel to frame (outer side)...
... after the flextube is a flange.
Next piece: some more parallel to the frame....
... and twisting over the frame (headshield there)...
... diagonal cross to LH ...

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Wow, thanks @Felde for the images, huge help!! I'll be sure to update the thread with all the exhaust/muffler work once I get to it.
 
Not sure where you are, but report back who you use and cost, if you don't mind - interested in rehabbing mine next spring going up in size [currently a monster mash of different sizing.]
 
Not sure where you are, but report back who you use and cost, if you don't mind - interested in rehabbing mine next spring going up in size [currently a monster mash of different sizing.]

Will do, I'm in Boulder CO and I plan on using Boulder Muffler when I get a chance.
 
Well the new exhaust system has been installed and they did an beautiful job. Custom 2.5" from the manifold all they way back. The reign of terror of the loud 3B is over - it's like a new car. Drivability has improved drastically, especially on the highway, and my neighbors probably like me more now.

They followed the stock routing nicely. The only difference was that they went straight over the transfer case output (perpendicular) and then took a 90 degree bend into the muffler on the drivers side. The stock routing is more of a diagonal, but this actually looks a lot cleaner and gives more space around the prop shaft / transfer case. Can post pics if desired.

@loeky I used Boulder Muffler and they charged me ~ $800. I was expecting closer to $500, but my fault for not getting an estimate first. Also, it's Boulder, so everything seems to cost about 50% more 🤑. Anyway, this has been one of the best upgrades yet and worth every penny even if the cost was higher than expected/average.
 
Well the new exhaust system has been installed and they did an beautiful job. Custom 2.5" from the manifold all they way back. The reign of terror of the loud 3B is over - it's like a new car. Drivability has improved drastically, especially on the highway, and my neighbors probably like me more now.

They followed the stock routing nicely. The only difference was that they went straight over the transfer case output (perpendicular) and then took a 90 degree bend into the muffler on the drivers side. The stock routing is more of a diagonal, but this actually looks a lot cleaner and gives more space around the prop shaft / transfer case. Can post pics if desired.

@loeky I used Boulder Muffler and they charged me ~ $800. I was expecting closer to $500, but my fault for not getting an estimate first. Also, it's Boulder, so everything seems to cost about 50% more 🤑. Anyway, this has been one of the best upgrades yet and worth every penny even if the cost was higher than expected/average.
Missed this earlier, but really appreciate the info. Have used Boulder Muffler before too and he was great, but not cheap. Knowing he did yours makes going to him easy for me and the BJ73. Considering the wholly custom work here, surprised it wasn't more expensive honestly.

If you don't mind, please do post the pics for reference - will use them directly this summer to get myself sorted, too!
 
Missed this earlier, but really appreciate the info. Have used Boulder Muffler before too and he was great, but not cheap. Knowing he did yours makes going to him easy for me and the BJ73. Considering the wholly custom work here, surprised it wasn't more expensive honestly.

If you don't mind, please do post the pics for reference - will use them directly this summer to get myself sorted, too!
Will get under there and snap some pics when I get a chance!
 
I just realized my exhaust had disintigrated to garbage. So have gone looking, but seems the only part available is the front pipe
the second and third factory parts are no longer available. I like your system, will take cues from that.
Is it 2 1/2" all along?
Yep 2.5 all the way 💨
 
Yep 2.5 all the way 💨
Are you able to send me some pics of the routing in the front wheel well? I am looking at going to a 2.5 in but am concerned that >35 inch tires will rub. I was looking and was thinking of modifying the body mount so i can feed the tube through and give more clearance for turning radius.
 
Did you see my pic of the stock routing at the beginning of this thread? I don't have exact metrics on my pipe diameter right now (could measure later the day when needed, though), but I think, a little more or less wouldn't make all the difference...
Cheers Ralf
 
Are you able to send me some pics of the routing in the front wheel well? I am looking at going to a 2.5 in but am concerned that >35 inch tires will rub. I was looking and was thinking of modifying the body mount so i can feed the tube through and give more clearance for turning radius.
If running 35’s have you followed the usual plan of moving front axle forward 1” or 30 mm like many do?

@Felde thanks so much for the pics. I managed to find both front pieces from the EU, and after
some delivery problems they are here. That flex piece you added is not factory is it? Seems like a
good thing to add though. Mine is 13BT but in all aspects identical. Big help for me to finally
get this job done.
 

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