Rerouting the exhaust? (1 Viewer)

[Rusty Cruiser]

I bought a 1995 about 6 weeks ago and have been working into getting into shape to use as a daily driver and for trail duty. I found a set of used rock sliders on FB marketplace for a great deal so I grabbed them. I tried mounting the passenger side slider today and found the forward catalytic converter is directly in the way of the forward support bracket for the slider. I did notice the slider is bent/knotched to allow for clearance for the pipe where it crosses over the frame rail FWIW. While I was messing with the slider today I noticed in general the exhaust system is in pretty bad shape anyway. The pipe going into the muffler is loose and the muffler has a hole rusted in it as well. I also noticed a rubber strap hanger that may not be original so I'm not sure of the exhaust is even positioned exactly as it should be where the cats are. Considering the shape the exhaust is in, it could pretty much be replaced from the manifolds back. I really don't like the location of the cats or the resonator as they seem to hang pretty low and would be easy to squish on the trail. I was curious if anyone has found a better routing solution, with or without cats (I am in a state without emissions inspections) or possibly a setup that replaces the double cats with a single unit that tucks in a bit better(mine are oriented vertically which seems less than ideal, possibly to limited heat exposure to floorboards above). I didn't find much trying a search but I'm guessing there is a thread or two concerning this if anyone could point me in the right direction. Thanks!

 

[CrabCake]

Your cat setup is OEM the way it is, not sure after that though. White Knuckle makes their sliders per year grouping to accommodate this...my 94 is totally different with side by side cats and an over frame pipe from there back (which I prefer for clearance). You could have a shop do a high flow round cat that sits much higher and custom do a whole system back if you want...I have a shop near me that has done a few projects like this for me on various vehicles and were about $1k with stainless pipe and custom mandrel bent/welded from the header back.

Do a little research on the 93-94 model year exhaust and you'll see what I mean with the routing...

 

[Rusty Marlin]

they are definalty hanging lower than mine... that doesn't read well.
There are threads on relocating the exaust inside the frame rail between the trans and the frame.
It looks very tight to me and I don't know why it doesn't cook the trans and transfer, but peeps do it.

1FZ-FE Inside the frame Y-pipe

Just trying to gauge how many people would be interested in a y pipe that bolts to the factory manifolds and pushes the exhaust inside the frame like I have? What material would you want it built out of? Ceramic coated or shipped raw? Thinking of doing a small production run! You would need to...

forum.ih8mud.com

There's a cruiser club out of Charleston, there could be some folks there that have the mod and will let you look.
You'll need to check the Club House section for contact.

 

[Rusty Marlin]

..

 

[mudgudgeon]

Find a 105 series set of manifolds, and run the exhaust down the inner side of the frame rail
Toyota did this with 105 series 1fzfe ABS 105 series diesel. Much straighter path, and it can be tucked up above the underside of the frame rail the whole way to the rear.

 

[Rusty Marlin]

Find a 105 series set of manifolds, and run the exhaust down the inner side of the frame rail
Toyota did this with 105 series 1fzfe ABS 105 series diesel. Much straighter path, and it can be tucked up above the underside of the frame rail the whole way to the rear.

Not sure I completey follow:
The 105 diesel and the 105 1fzfe run the same exaust manifolds?
Or the 105 1fzfe runs the same exaust routing path as the 105 diesel?

 

[mudgudgeon]

Or the 105 1fzfe runs the same exaust routing path as the 105 diesel?

Yes

 

[Marvelicious]

I bought a 1995 about 6 weeks ago and have been working into getting into shape to use as a daily driver and for trail duty. I found a set of used rock sliders on FB marketplace for a great deal so I grabbed them. I tried mounting the passenger side slider today and found the forward catalytic converter is directly in the way of the forward support bracket for the slider. I did notice the slider is bent/knotched to allow for clearance for the pipe where it crosses over the frame rail FWIW. While I was messing with the slider today I noticed in general the exhaust system is in pretty bad shape anyway. The pipe going into the muffler is loose and the muffler has a hole rusted in it as well. I also noticed a rubber strap hanger that may not be original so I'm not sure of the exhaust is even positioned exactly as it should be where the cats are. Considering the shape the exhaust is in, it could pretty much be replaced from the manifolds back. I really don't like the location of the cats or the resonator as they seem to hang pretty low and would be easy to squish on the trail. I was curious if anyone has found a better routing solution, with or without cats (I am in a state without emissions inspections) or possibly a setup that replaces the double cats with a single unit that tucks in a bit better(mine are oriented vertically which seems less than ideal, possibly to limited heat exposure to floorboards above). I didn't find much trying a search but I'm guessing there is a thread or two concerning this if anyone could point me in the right direction. Thanks!

View attachment 3683560

That exhaust routing is definitely a source of frustration for me and it's on the list of things to fix as soon as I come up with a solution that I'm happy with. I'm sure it's a great location for heat management, but for an off-roader, it's asking for trouble.

There are threads on relocating the exaust inside the frame rail between the trans and the frame.
It looks very tight to me and I don't know why it doesn't cook the trans and transfer, but peeps do it.

I've been thinking about that. There are some pretty amazing heat shielding materials these days that were a lot more out of the reach of ordinary folks and production model vehicles back in the 90s. I know a lot of folks do it for looks on their hot-rods, but the original purpose for ceramic exhaust coating was heat management. One could coat the Y-pipe and mid pipe and maybe some heat shields to put between the cats and drive-train. If the exhaust were up out of harms way, the expensive coating would be safe as well. Once you get past the cats, you're back to more or less stock routing. Carbon felt insulation for heat shields is another thought.

Find a 105 series set of manifolds, and run the exhaust down the inner side of the frame rail
Toyota did this with 105 series 1fzfe ABS 105 series diesel. Much straighter path, and it can be tucked up above the underside of the frame rail the whole way to the rear.

I've heard that the 105 Y-pipe can be difficult to get in the US since we never had that model. I'm probably going to give it a try at some point.

 

[mudgudgeon]

I've heard that the 105 Y-pipe can be difficult to get in the US since we never had that model. I'm probably going to give it a try at some point.

Id guess you'll have to import it yourself.

I'm sure there's heat implications, but if Toyota figured it was OK, I reckon it's OK

I added heat insulation to the floor of my older cruisers because with stock exhaust, heat transfer to the cab was a problem. Never noticed any difference with modified exhaust.

My 105 had heat shields under the floor, nothing directly between exhaust and transmission that i remember

 

[Marvelicious]

Id guess you'll have to import it yourself.

I'm sure there's heat implications, but if Toyota figured it was OK, I reckon it's OK

I added heat insulation to the floor of my older cruisers because with stock exhaust, heat transfer to the cab was a problem. Never noticed any difference with modified exhaust.

My 105 had heat shields under the floor, nothing directly between exhaust and transmission that i remember

So, remember the other day we were discussing Aus' laws on bumpers... The good ol' USA doesn't care how many babies you run over, but heaven forbid you run imported exhaust components! I'm not 100% sure, but I think they block them at customs when they catch them.

This is aftermarket of course, but it's the same deal. I've heard Partsouq and Amayama just cancel the orders. I'd be happy to be proven wrong of course.

 

[mudgudgeon]

So, remember the other day we were discussing Aus' laws on bumpers... The good ol' USA doesn't care how many babies you run over, but heaven forbid you run imported exhaust components! I'm not 100% sure, but I think they block them at customs when they catch them.

View attachment 3683963

This is aftermarket of course, but it's the same deal. I've heard Partsouq and Amayama just cancel the orders. I'd be happy to be proven wrong of course.

But, but, mah freedums!

 

[mudgudgeon]

Shoulda brought some with me!

 

[jonheld]

On my 97 LX450, I used the Magnaflow downpipes/cat (Magnaflow part# 23120), the BRExhaust muffler from Summit (228-241), and had a local hot rod shop build a custom over the frame exhaust out of T304 stainless. Exits behind the right rear tire level with the rear bumper skids.
I supplied all new OEM hardware/hangers/donuts/O2 sensors, stainless O2 bung, and had the downpipes/cat ceramic coated before installation.
Passes NJ inspection with a single cat. No issues.

The Magnaflow cat sits horizontally as opposed to the OEM vertical orientation.
The single cat allows it to loop over the frame as opposed to under, and the new muffler is a smaller diameter than OEM and uses OEM hangers. The shop added 2 additional SS hangers for more support.
Basically it cleared out the entire right side of the vehicle. I had a custom cat skid plate built which bolts to the frame and inside of the right slider to protect the cat from rocks.

The sound is slightly louder than stock, but not annoying. I'm not a child, so I never needed/wanted a loud exhaust. I've done several road trips since installation, and my wife hasn't complained once, so I'm all set.
Just got back from 3 days of rock crawling and banging around in the woods and the exhaust is untouched.

 

[Rusty Cruiser]

On my 97 LX450, I used the Magnaflow downpipes/cat (Magnaflow part# 23120), the BRExhaust muffler from Summit (228-241), and had a local hot rod shop build a custom over the frame exhaust out of T304 stainless. Exits behind the right rear tire level with the rear bumper skids.
I supplied all new OEM hardware/hangers/donuts/O2 sensors, stainless O2 bung, and had the downpipes/cat ceramic coated before installation.
Passes NJ inspection with a single cat. No issues.

The Magnaflow cat sits horizontally as opposed to the OEM vertical orientation.
The single cat allows it to loop over the frame as opposed to under, and the new muffler is a smaller diameter than OEM and uses OEM hangers. The shop added 2 additional SS hangers for more support.
Basically it cleared out the entire right side of the vehicle. I had a custom cat skid plate built which bolts to the frame and inside of the right slider to protect the cat from rocks.

The sound is slightly louder than stock, but not annoying. I'm not a child, so I never needed/wanted a loud exhaust. I've done several road trips since installation, and my wife hasn't complained once, so I'm all set.
Just got back from 3 days of rock crawling and banging around in the woods and the exhaust is untouched.

I really appreciate the info! I have ordered the Magna flow downpipe/cat and the BRE exhaust along with a bunch of the OEM connecting parts. Any chance you have a pic of the custom over the frame pipe and muffler back pipe the shop did for you? Once I have everything I'm going to find someone who can do the same for me. Thanks again, Seth

 

[jonheld]

I really appreciate the info! I have ordered the Magna flow downpipe/cat and the BRE exhaust along with a bunch of the OEM connecting parts. Any chance you have a pic of the custom over the frame pipe and muffler back pipe the shop did for you? Once I have everything I'm going to find someone who can do the same for me. Thanks again, Seth

The first pic is an original attempt back in 2018 before I had it replaced with SS, but the basic routing is the same. You can see how the Magnaflow cat sits much higher. There's a custom skid plate that mounts to the 4 tabs welded to the inside of the slider and the 2 outer bolts for the crossmember along with another bolt to the frame rail that keeps the cat and pipes protected.
Pipes and hangers were changed to T304, the muffler was tucked up higher and further away from the rear drive shaft, used OEM cushions/hardware, and a slip joint was added with a SS band clamp for removal.

And yes, I know the last 2 pics are filthy. That was before a good power washing and after a long road trip through the North Maine Woods.

 

[Saito]

My exhaust is routed similar to Jon’s. Except inside the frame entirely. ARH headers for a 105 series modified and turned up and in. Magnaflow single cat and magnaflow muffler plus two resonators. It got pulled and heat wrapped recently and the transmission/t-case wiring got heat shielded. All 2.5” except up front where the collector is 3” and I’ll re-do the rest to 3” hopefully this winter. Sounds right to me and I get asked if it’s got a V8. Just rumbles.

 

[Rusty Cruiser]

Thank you both!