Custom exhaust question... (1 Viewer)

[gregnash]

Looking for a little welding project for myself when I am done messing with the axles.
Previously when I did the exhaust on BeBe, my FJ60, I used a converter/adapter to go from the stock 2.25" exhaust up to the 2.5" from the down pipe back. Basically this was stock exhaust manifold until just under the drivers foot bed then the adapter to 2.5" with a CARB compliant 2.5" CAT and then 2.5" muffler (Thrush Welded) all the way back to dump out just behind the rear tire.

Looking at the few pics of custom exhaust or aftermarket exhausts I have found the on forums here, most seem to replicate the stock path all the way back to dump from under the bumper. The few bolt in aftermarket options do the exact same thing, so wondering why no one seems to do a side dump for the exhaust on the 100 series?

Also, from what I have been reading it looks like the area that I would probably cut into the exhaust to add the aftermarket muffler would be just after where the Y is, and connects to the stock muffler. Some people say that it is just about 2.5" there and other state that it is closer to 2.25". Anyways, trying to figure out how I want to go about this. After that will be determining where I am gonna splice into the system and either go 2.5" or 3.0".

 

[TRAIL TAILOR]

The SEMA/OEM files layout they exact paths, bends, bung orientations and exits. These are uploaded into the CNC benders and the parts are made. The ratio of a customer wanting a stock path/part is probably 100:1 to a custom customer.

Vendors make/sell to the masses not the other way around.

As far as the piping size, some guys measure OD vs ID or vice versa... Also if the exhaust has been damaged by offroading getting an off the shelf exhaust fitting to slide right on may be a challenge. Be prepared to "shape" the pipe to your liking/need.

J

 

[gregnash]

Thanks Jason. Yeah i realize that most are going to want to go the route of a OEM fit version. That is simply out of simplicity sake, and those that don't will likely just throw an aftermarket muffler in-line, keeping the resonator and everything else.

I guess a better question is whether there would be any benefit to the side dump vs. the stock path dumping out the rear? Aside from that, comes the discussion of increasing the diameter (whether inner our outer diameter) is of much benefit.

When I go down this road I will likely get rid of the resonator, but plan to add v-bands in sections to allow me to change things as necessary. As I was thinking about it more I realized that with the OEM tow hitch, there is protection for the exhaust tip in the stock exit. If I were to do the side dump behind the tire, then I could risk the exhaust tip getting bend should I hit something while wheel. However, really I wheel all of a handful of times during the year, and at that the wheeling isn't overly difficult. So really the likelihood of me hitting is pretty unlikely.

I would like to see the side dump.

 

[DirtDawg]

I would remake the y-pipe. The stock one is very restricting.

 

[gregnash]

I would remake the y-pipe. The stock one is very restricting.

Yeah at that point I will probably take to an exhaust shop. I can do simple angles and whatnot but when getting to the more complex stuff, that will need a pro.

 

[wildsmith]

I used a muffler with twin inlets instead of the OEM Y.

 

[gregnash]

I used a muffler with twin inlets instead of the OEM Y.

Interesting... any particular reason? Or just to avoid the Y collector. Did you do yourself or have shop do it?

 

[wildsmith]

It just felt like a better solution and iirc meant I could get slightly better routing of the pipes. I did it myself, using lots of small sections welded together to get the curves needed though, so it's not as pretty as a shop would make it.

 

[Biga27110]

Pics would be cool to see. Im looking to go the way of custom also.

 

[gregnash]

Some pics of my stock setup. I have the stock OEM tow hitch as well.
Untitled by Greg Fisicaro, on Flickr
Untitled by Greg Fisicaro, on Flickr

You can see that the stock resonator is just behind the hitch so I would remove the resonator as well as changing the muffler. Looking at it there does not seem like there is a whole lot of room to have an axle back (behind tire) dump for the exhaust, so probably would not net me anything special. If I did not have a hitch then might net me a bit more departure angle, no worry about smashing the tailpipe.

 

[wildsmith]

This is what I ended up with. The extra kink keeps it tucked up out of the way - iirc the stock routing hangs down a bit.

My over axle routing is the same as OEM but made up in 2 sections with slip joints for easier fitting and removal. I tried it without a rear silencer but it was just a bit too intrusive for highway cruising for me so I fitted a less effective after market silencer and got the right balance for my tastes.

 

[gregnash]

Nice... I am realizing now that I did my 60 exhaust of out mild steel and then painted with exhaust paint to keep from corroding. Seeing as this truck will be a bit more complex (in my head) I may just take to a shop to have them do stainless. Don't really have access to a tig to do on my own, so.. first world problems.