I installed the Thermal R&D exhaust last month but just got around to really trying it out this Memorial Day holiday. Wife and I took a 1000 mile round trip thru the Ozarks. The exhaust was well worth the money paid just for the heat reduction alone. The transmission tunnel still gets a little warm but not even close to the heat put off by the stock set-up. I think I would have paid twice the asking price just for the heat reduction we saw!
No heat at all, absolutely none at the passenger floorboard. The ride was so comfortable for my Wife compared to the stock system and she was so happy. Me too.
The sound is great but that is a personal preference. I do not care for loud exhaust, especially the way we use the Slingshot in touring the states. It did have a lower growl, but nothing really much louder than stock.
I have no way of proving this, but it seems like the power band got moved higher in the RPM range. Not a bad thing, just different. Gas mileage seemed a little better too, but not a bunch of difference. No fumes at all, I did not remove the cat.
I installed the system myself, on my back in my garage in a weekend. Not too difficult if your body can take getting up and down and sliding around under a vehicle on jack stands. I did pay a small price at work the next day or two in being somewhat sore from doing it, but I would do it again in a heartbeat just for the heat reduction.
I have read where some people were not able to use the stock heat shield Polaris put behind the muffler, I had no problem reinstalling that part.
Hope this helps someone to make the purchase if heat is your passengers problem because that problem will go away, have no doubt about that.
