Originally Posted by PCarOMFS

If I took long trips in it I would do SMB and keep OEM center muffler or get the upcoming Soul center muffler.

Originally Posted by jhott66

Can you please explain what the new Soul center muffler bypass is how it differs from their current center muffler bypass?

Originally Posted by Xec

There's a lot of permutations possible with GT3 exhausts and I've tried to hear many in person. As most of you know, there are three sections of the GT3 exhausts that you can swap: headers, side mufflers, and center mufflers.

I'll try to provide a summary of my experience below, by increasing volume:

1. Side Muffler Delete: this is the tamest aftermarket configuration. After choosing between valved or no-valves, they all sound effectively the same regardless of brand and material. Great for track because the volume isn’t too bad, and it removes a ton of weight. Also removes a bunch of heat off the rear tires. Most of the GT cars I've seen on track run this setup. Any decently priced pair from a reputable manufacturer would work great.

2. Center Muffler Delete: this is a big step up in volume from SMDs. The volume and tone will vary greatly with design and material. Designs with expansion chambers (GMG, Soul, Dundon, etc) are significantly louder than those without (Sharkwerks, Akrapovic, JCR, etc). Titanium exhausts tend to have a more metallic timbre than those made with stainless steel. The difference between brands with the same design is minuscule (GMG and Soul sound nearly identical; Sharkwerks and Akrapovic sound nearly identical). The Dundon Mini Crack Pipe is easily the loudest center bypass (and also has the biggest megaphone design).

3. Headers + SMD: this assumes retaining the OEM center or an aftermarket center muffler (e.g. Dundon). The volume and tone varies greatly with design and material of the headers, and if you are catted or no cats. Most headers tend to be expensive ($5K and up). If I'm paying that much, I'd only consider Dundon. They have a true long tube design (inherently deletes the OEM side mufflers as the headers are rerouted to occupy that space) that offers real power gains. Paired with a center muffler, it's got a distinctively beefier tone that's different than that of catback configurations. In strict volume, this setup with a factory center is about as loud as quieter CMD above. An aftermarket center like Dundon's is about as loud as an expansion chamber CMD.
*I have not heard any Headers + CMD setup so I can't comment on that. Given the volume increase from a CMD, I'd probably guess it would result in a big volume difference between valves closed/open.

4. Center Delete + Side Delete: this is basically a catback straight pipe and is significantly more aggressive than anything above. Valves don't do much with this setup as all the mufflers have been deleted, so you're just rerouting gases through different sections of straight pipe. I have this setup and on my track day I couldn’t really hear my instructor even with race coms. Sounds epic though and I was the loudest car on track. Your choice of center delete makes the biggest difference in volume here. The Dundon Full Crack Pipe is the loudest version of this setup (comes with a side delete).
OP's SPM RSR exhaust is probably similar to this. I've heard the JCR Race Pipes, which is an all-in-one version of this catback straight pipe setup. It has a very distinctive high pitch at 6-9K RPM. It is quieter than catback straight pipes with an expansion chamber CMD, but still louder than any of the previous configurations mentioned above.

5. Headers + CMD + SMD: never heard this personally but a friend who has said it's 3x louder than my full Soul catback and was the loudest car he'd ever heard. Your ears and neighbors will hate you. When I get a RS, I plan on trying this setup LOL.
1. Side Muffler Bypass: this is

the tamest aftermarket configuration. They all sound the same regardless of brand and material. Great for track because the volume isn’t too bad, and it removes a ton of weight. Also removes a bunch of heat off the rear tires. At MSRC, all the GT cars I saw out there ran this setup.

Originally Posted by alberthyc

I am looking at pairing a side muffler for my Sharkwerks sport exhaust.

Would you recommend Dundon Side Muffler Delete, JCR titanium side silencer bypass (valved), GMG side muffler delete kit or FVD Brombacher valved side muffler bypass?

Originally Posted by PCarOMFS

Soul is developing a center muffler (not a delete) they call Superior Center Muffler which is reinforced and won’t crack like the OEM center mufflers tend to do. It’s analogous to the Dundon lifetime center muffler accept it will be made out of 304 stainless. Paired with their side muffler delete it’s going to be much tamer compared to the side muffler and center muffler delete combo. Although I imagine it’ll sound much better/louder than the OEM center muffler with side muffler delete. It should be available some time this quarter. I spoke to John Gaydos about it which is where this information came from.

Originally Posted by jhott66

Thank you. I almost bought the Soul center muffler delete last month but held off thinking the side muffler delete was the better option. Sounds like I might want the side delete and the new center muffler.

Originally Posted by PCarOMFS

I have the non-valved Soul Performance SMB and CMB pipes. It’s very loud and sounds glorious. There is drone from 2-3k rpm but once traveling at around 70mph it disappears. My car is mainly a track car so it’s all good. If I took long trips in it I would do SMB and keep OEM center muffler or get the upcoming Soul center muffler. You can’t go wrong with Soul Performance. They’re top quality, great customer service, reasonably priced, and lifetime track and street warranty.

Originally Posted by silvertige

I have the sharkwerks with plugged valves. Pretty happy with it as its not ridiculously loud and doesn't have the weird sound transition between 2-3k. No drone, and great sound to my ears.

Originally Posted by Nmora991

excuse my ignorance, can you elaborate on the “plugged valves”?

thank you!

Originally Posted by Nmora991

excuse my ignorance, can you elaborate on the “plugged valves”?

thank you!

Originally Posted by silvertige

Vacuum lines to the side muffler valves are detached and plugged or covered/sealed with a screw on both right and left sides. This keeps the valves in an open position at all RPM's. Normally, below 3k rpm, the valves are closed even with the sport exhaust button pushed and where the weird transition happens at 2-3k rpm. The negative is possible drone, but I haven't been bothered by it with the sharkwerks.