At first I wasn't sure if the universal SuperTrapp kit would work at all for the G650X Challenge but I decided to take the small financial risk and try it anyway. Turns out, it was far easier to install than I had imagined. I had to use a little creativity for a mount though. Here's what I came up with.
Here's what you need:
a. SuperTrapp universal kit.
b. Exhaust heat wrap (you can find this at just about any auto parts store).
c. High temp silicone seal (500 degrees)
d. Stainless steel locking ties (any auto shop has these)
e. Stainless steel hose clamp (3in - 4in diameter range)
Installation:
1. Wind the exhaust wrapp around the subframe, just below the factory exaust mount (the stub that holds rubber grommet on the factory exaust). Use the high temp silicone seal to keep the wrap in place while you apply the metal locking ties.
2. Use two metal locking ties to secure the exhaust wrap.
3. Install the assembled universal SuperTrapp, check to be sure that the exhaust wrap is between the SuperTrapp body and the subframe and that there is no metal to metal contact between the SuperTrapp body and the subframe.
4. Wrap the hose clamp around the end of the SuperTrapp body, just below the diffusion plates (don't cover the diffusion plates!) and around the factory stub mount on the subframe. Tighten the hose clamp so that the SuperTrapp body is snug against the subframe (with the exhaust wrap buffer in between the SuperTrapp body and the subframe).
Your done!
This hasn't stood the test of time yet but first indications look promising. I'll report back with any issues or modifications that come up.