I know that many of you won’t believe me, but my exhaust saga is over. Really…it’s over. (Well, unless Akra wants to send me an Evolution for free.) I’ve settled on the GMG. It’s on my car for several hundred miles now, so I think I can make a decent assessment of the difference between it and the Sharkwerks option.

991 GT3 Start up & Slow Rolling Sharkwerks Bypass - YouTube

Porsche 991 911 GT3 Sharkwerks Bypass Exhaust - YouTube

991 GT3 GMG Exhaust - Center Section - YouTube

991 GT3 GMG Exhaust - Explanation & Interior Sound - YouTube

First, let me say this. After all my messing with different exhaust iterations, I’ve come to the conclusion that the SW center bypass is the best “overall” solution. Let me emphasize overall. I get that I’m a bit of an odd dude and likes to subject himself to unneeded punishment always in pursuit of “better.” So the question one should logically ask is, “What does better mean to me?” I think this is largely subjective, but here are my observations on why I think the SW is the best overall, but the GMG is still the right choice for me.

991 GT3 Sharkwerks vs GMG Exhaust - YouTube

With the valves connected (not important to me personally), neither one suffers from drone, but disconnected the Sharkwerks does so much less. The margin between the two is pretty wide. If I were to scale it:

1.) Side Muffler Delete: 7/10
2.) GMG w/ Disconnected valves: 4/10
3.) Sharkwerks: 2/10

The GMG does drone a bit, but I’m okay with this. I wanted more “nasty,” and apparently that is part of the price I have to pay. I loved the sound of the side muffler delete, but my threshold is probably a 6/10. There are also different resonant frequencies of drone and the GMG version of it is not bad to my ear. For me, the opening and closing of the valves is much more displeasing than some extra sound on the highway. If I were ever taking a long trip, I’d probably reconnect the valves with the GMG, but wouldn’t worry about it with the SW. So if you want the valves disconnected and a relatively drone free environment, the SW wins hands down.

The sound at lower RPMs is where the GMG shines for me. The main reason I decided to stray from the SW was due to the note sub 5,000. In my estimation, the SW bypass sounds about the same as stock with 25% more amplitude. The sound of the stock GT3 is certainly not bad, but gives me a hollow tone that I don’t care to hear. Now I’m nitpicking here, but I wanted the car to sound different when I’m cruising around town since that is what I do more often than screaming down a back road at 9K. Despite being pretty reserved, the adolescent in me wants to let everyone know I’m there, and GMG gives me that extra oomph as well as adjustment to the hollow sound that I was so desperately trying to accomplish. If I were guessing, I’d say the GMG is another 15% louder over what the SW does to stock with a slight change in tone. You can probably see why in the photos below. The size difference between the two is pretty significant. On a side note, if you can get over the single exit, the Chris Smith Racing offers the best tone vs. drone out of the three.









When it comes to aesthetics, the GMG also wins this one. Although, the black coated SW tips were certainly not bad, the GMG looks less bolted on. I know the SW is emulating the factory, but GMG with the single piece of metal that transitions directly to exit really appeals to me. They did a great job of choosing a great looking size to fill the rear bumper cut-out. I would absolutely recommend the black ceramic coated version as it matches the rest of the black trim much better than raw stainless. I will state that the SW does install and stay put more accurately. If you were to pull on the GMG it will twist upward. This is because it is not attached to the H-bracket with bands like the SW is. I’m not sure that this will present a problem, but I would rate the SW as a better design for installation.

Sharkwerks











GMG










Since the GMG is louder, a little deeper, more aggressive at lower RPMs than the Sharkwerks, it beats in the Sharkwerks and makes it perfect for me. So if you are anything like me and have that kid inside you clawing to get out every once in a while, the GMG is the way to go. The SW is more civilized option. Either way, you can’t go wrong.

 

Matt,

I've lost track of all the different configurations you've been through, but certainly appreciate that you did.

So just to be sure as of now you have just the GMG center bypass correct? Or do you also have the side muffler bypass as well?

 

You and me both. Everything is stock except the GMG center bypass.

 

Off topic but, Matt your youtube channel and website is a true joy. I really appreciate all the time and effort you have put into generating great content. You really have provided a great service to enthusiasts everywhere.

 

Great content. I too like the sound of the GMG better. Louder and more aggressive.