When I first bought my '15 Limited I put SE Street Cannons on it. I liked the sound. Nice low Harley rumble. Then I put on V&H Power Dual headers... Nice low rumble got lots louder and not a pleasant tone at all. Hollow and raspy sounding. Well on the '15 King I went with the Nightsticks. Nice low rumble but could be a bit louder. They come with 10 discs. I had extra open end caps in the garage from my SE FatShotz and put them on. Same as the SE Cannons, got lots louder but not a good tone at all, kinda like changin the headpipe. Beauty of the Nightsticks is though you can experiment LOTS more. I put the close endcap back on and started adding discs. Running 12 each side now. Flow increases but no nasty raspy sound. Just thought I'd mention this for guys that are using the cannons or nightsticks.

 

Changing the Head Pipe will make just about all mufflers loader, due to no Catalytic Converter.

 

I like the Fatshotz because they come with a wrapped perforated baffle that cuts the high frequency raspy sound. I believe the Nightstick has a solid tube baffle. A perforated baffle is an option from Supertrapp who makes the Nightstick.

 

Yea, I must say I'm impressed with the power of the Rushmore's right outa the box, first bike I didn't feel the need to add a hotter cam. For now the cat head pipes are stayin on. I never was really convinced they effected performance all that much, it was more of a heat issue than flow. I've seen test results that show the cat really doesn't effect the flow all that much. It must be the wrapped perforated baffle on the FatShotz makes the difference with the caps. The FatShotz come with an open end cap and 10 discs, I'll play with the discs. According to SuperTrapp the open cap = 10 discs.

 

I had the same issue with the SC pipes, so much so that I put the stock head pipe back on - its not so much the noise level as the crappy tone. Probably going to try the E-series with their header.

 

I do like SuperTrapp. Racers have been using them for many years since the allow you to tune the exhaust for sound, torque, and horsepower changes. Some other exhaust manufacturers have tried that concept but don't know of any that succeeded like SuperTrapp. So far 12 discs and closed caps sound great and perform well, no loss of torque