I get a lot of questions about the rear-exit exhaust on my quad and while I have a blog entry up about this, figured it would be a good tech article as well.
I have a trakhamr conversion, but I would expect this would apply to any of the other conversions as well. I also have the Welter dual exhaust, with the Y pipe and them originally exiting at the license plate area at the top of the tub.
The challenge is the way the Welter routes, and probably applies to the side kick exhaust as well. The Trakhamr torsion box gets in the way of the Welter routing (or vice versa, depending on how you want to look at it). This applies to both the 2" and the 2.5" exhausts.
A bit of definition, the torsion box is the main mounting point of the quad conversion and it's the box that goes in place of where the angle drive used to sit.
Here is a view of my setup from underneath. The blue outlines the torsion box and the red arrow is where the Welters used to run.
As a side note, the dual will also hit up near the top of the tub, there is a cross beam that would hit the Y-pipe, shown in blue here. Troy with Trakhamr said he could modify this to allow the Welters to go up, but I chose not to, wanting to lower the mufflers for the exhaust fume problems most people with tops/tall windshields have.
So, to fix these challenges? Well, you are going to have to find a muffler shop willing to tackle it (or DIY). Where I live, I went to 4 places that either said nope, or it would be at least a month before they could touch it. If you are near the Dallas/Fort Worth area, I highly recommend McKinney Muffler and Speed Shop, Nick took great care of me, prices are good, and he gives a cash discount.
In the first image, you can see where we basically took a bend in the original pipe and pointed it out a different area of the torsion box and then the rest was pretty much just cutting up the old Y-pipe and setting it up.
If you have a Welter, you know how much fun taking the pipe sections apart are, so I spent the money to have v-bands put in place, at every joint in the whole setup. I highly recommend you consider this, so that you can easily take out sections and just get the whole thing apart if you need it.
Also, you'll basically need one at the rear if you route the pipes the way I did, otherwise it won't ever be able to come apart without cutting it.
I'm extremely happy with how it came out and the looks of it.
Hit me up with any questions.