Outer Limits 4x4 Board

Just about get a custom exhaust on the 80 series and wanted to put a 3" exhaust inside the chassis rails (will sit between transfer and rail).
I have heard that this has been done before, but wanted to know if the heat off the exhaust will affect the transfer or transfer oil in any particular way, as they sit very close.

Cheers,
Paul

Nope. Although I have 'heard' of a few 80 series fires being attributed to leaking transfers on the exhaust, particually turbo's as the exhaust temps are hotter.

You could always wrap the exhaust in that heat wrap stuff. I would just stick with it outside the rail, and put sliders on or similar to protect it off road.

Acl make a excellent heat shield material. My exhaust has been inside my bj74 rail for over a year witness 25mm clearance no problems with heat shield

I ran the exhaust like that on my 80 with no problems.
when it had the stock exhaust on it, the floor pan used to get really hot next to the trans tunnel. I figured it was from heat blowing back from the turbo and exhaust manifold, and figured the transfer etc would also be copping the same heat.

the 105 and 100series cruisers have the standard exhaust between the chassis and gearbox/transfer too, so I guess Toyota didn't consider it as a problem

Definetly isnt an issue running it there. With the exhaust tape/wrap, it actually absorbs moisture as it cools down and rusts out your exhaust. Plus it will retain water when you do water crossings and mud runs. Its good stuff, but just not ideal for the 4x4 world. If your really concerned, maybe just run a heat shield next to the box. Just some food for thought. Ash

My 80 turbo has had it running down the inside for years now with no probs, thats what the 100's have.

Thanks for the replies.
Any issues with fitting 3" between the transfer and chassis?
Will the 3" be a strait fit or will it have to be ovalled?

Also have you had the exhaust shop weld you up a custom dump or is there a dump pipe available off the shelf to suit?

I was originally looking at the beaudesert but after speaking with them they say it's not compatible as it's designed to run outside.

Cheers,
Paul

3" fits all the way to the rear without needing to be crushed. It needs a couple of careful bends to get past the transfer case, and I cut a little tab off the side of the transfer case. Clearance is tight (approx 10mm)
I'm not aware of any aftermarket dump pipe to do this. I made my own dump pipe and the complete exhaust. I made my dump pipe in one piece to the rear of the transfer case and solid mounted it to the bellhousing and the back of the transfer case, then fitted the a 350mm long braided flex pipe to eliminate vibrations. From the transfer case back the exhaust is suspended on rubbers from the chassis. I was told a long flex pipe was over kill, but with 10mm or less clearance in places, I had no rattles anywhere

I would expect Bauedesert would be able to make minor mods to a HDJ100 exhaust system to work with the 80 series. They are basically the same, if anything there is more room to run it on the 80series as body mount and crossmember brackets are smaller on the 80s chassis

when i was going to get my 3 inch exhaust i spoke to beaudesert and they said they could do it inside the chassis rail only thing is they wanted to have the car there to fit it

mistaboz wrote:Thanks for the replies.
Any issues with fitting 3" between the transfer and chassis?
Will the 3" be a strait fit or will it have to be ovalled?

Also have you had the exhaust shop weld you up a custom dump or is there a dump pipe available off the shelf to suit?

I was originally looking at the beaudesert but after speaking with them they say it's not compatible as it's designed to run outside.

Cheers,
Paul

Yes, there is a problem. I just ripped my old 3" out and replaced it. It used to rattle underload between the chassi and tranfer case. I cut a lug off the transfer and moved it for the most clearance either side, it still rattled. Have a flexi joint between the turbo and the transfer (near by). Doesnt help.

The other thing is make sure you use aluminiumised steel. Normal black steel will be rusted and falling apart inside 3 years. I went with a kit as I didnt want the note anymore. Dump with egt port, 3" full mandrel, hotdog and high flow muffler $1070 fitted. Didnt affect the power at all and flows just as freely.