Hello all! I’m new to the site, and I have seen some good advice on this forum and I’m hoping someone here can give me some insight or advice on an idea I have to get a louder note out of the stock exhaust inexpensively. Hopefully the end result will be a pleasant note too. First of all let me say I have several questions related to this modification. So please bear with me on the long post. I recently bought a 2019 Road King Special with the 114 M8. The exhaust is fully stock, and too quiet for my liking. All after market upgrades are more expensive than I’d like to spend $ on right now, and I don’t think I would end up liking any of the SE sounds either. So I pieced together slightly used stock take-off complete exhaust system parts from ebay for $150 hoping I could modify those parts instead of butchering the exhaust on the new RK. Also if any issues arise from modifying the used exhaust, and/or when I take it back to dealer for services, I could always throw the stock exhaust back on, keeping the warranty in tact as far as they will know. I have not taken the cat out of the header pipe because some people say it does provide a little bit of back-pressure, but I did weld a plug in the crossover pipe on the header, flush to the inner wall and ground it down so that it’s flush and not obstructing any exhaust flow from the cat out (The idea is to leave the exhaust looking stock with both mufflers there, but exhaust will only be coming out of the right side. I basically made it a 2-1 header with a cat). I wanted to make the header 2-1 because I have read that the best performance comes from 2-1 headers. And on the stock configuration 75% of the exhaust goes out of the right muffler anyway. My goal isn’t really to get more power, persay. I am very happy with the amount of power it has for now. But I know that opening the muffler will cause some loss of power issues, and I wanted to give it every bit of help that I could.

Question 1. Is the RKS 114 M8 already upgraded to any certain SE stage? I’m having trouble finding info related to that. Nothing says SE on it anywhere

Question(s) 2. I was able to drill out the small baffle on the outlet side of the right muffler while leaving part of the cone in place to hold the packing in (I’m tryin to avoid the tinny sound of a completely empty tailpipe by leaving the packing in place). There is now a hole there roughly 1.75 inches. The inlet side of the muffler has a cone/reducer inside of it going down to about 1.5 - 1.75 inches. Since I have essentially made the stock header 2 - 1, should I drill out the inlet reducer to a bigger diameter to compensate for more exhaust flow from both cylinders going through the single muffler? And should the outlet hole be any bigger also?

Question 3. I’m hoping that I can get a louder exhaust note without having to use a tuner. I plan on leaving the stock AC alone. Does anyone know if any of this is possible?

Thanks in advance

Have you checked out Fullsac? my Rg is older 2011 but I got a sport-pipe from them which was a modified OE head pipe and works amazingly well, not sure if they make one for the M8s but check the website out. More sound and more power they welded a 15 degree X-collector in it making it and X-pipe which kind of performs like a 2 into 1 because 65% of the exhaust flows out of the right side pipe.

I have been checking out aftermarket exhaust options for months, but don’t really want to spend the money on new parts right now and then have to tune it and whatnot. Thanks for the tip though

No retune needed with a Fullsac pipe, as long as you do not modify your air cleaner the other option is a baffle re-core kit they sell for the mufflers.