I had put the Thunder Air Kit, Cobra PowerPro, and Cobra Tri-Ovals on my 2013 Voyager. The bike got louder and burned more gas. So rich was the air fuel mixture that my exhaust would backfire on deceleration and pipes showed signs of black soot from the rich mixture. The Voyager didn’t give me a feeling that there was a performance increase. I'm going back to stock. I took off the PowerPro and Tri-ovals last Friday and then took a 200 mile trip. I gained 30+miles on my tank of gas. I watched the engine heat, no noticeable increase. Next I am removing the Thunder Air Kit and just simply going to use a K&N Air Filter. I guess I will advertise these parts to sell them, only used for about 700 miles.