Porsche 997 GT3 Valved Side Muffler Bypass Pipes


Shed 35 pounds and reduce heat soak while encouraging an exciting exhaust note from your GT3 while retaining valve functionality

+  Fits all Porsche 997 and 997.2 GT3 / GT3 RS vehicles 2006-2011
+  Weighs 35.4 lbs / 16 kg less than factory exhaust components (44.9 lbs vs 9.5 lbs)
+  Designed and built in-house at our Willow Grove, PA facility
+  All Soul Performance Products components are backed by our Lifetime Warranty for both street and track use

SKU: POR.997GT3.SMBV Categories: ,


DEVELOPMENT AND TESTING:  Deleting the side mufflers yields huge weight savings, helps with heat management in the engine bay and keeps the rear tires cooler. The hole leading into the secondary pipe is enlarged to equalize pressure in the center muffler – promoting longevity. Flex bellows allow for easy installation and increase durability under extreme racing conditions in a similar manner to OEM. Large 3″ diameter primary piping increases flow. High quality valves operate like factory.

SOUND:  The sound is smoother during the transition between open and closed versus a center muffler bypass. Valves closed tone is increased moderately while still comfortable with factory center muffler in place. Open the valves to reveal a refined, exotic pitch befitting of the high performance GT3 engine.

CONSTRUCTION:  Each set is made from mandrel bent T304L 3″ .065″ wall stainless steel tubing and high quality flex bellows for maximum durability.

BOLT ON AND GO:  Each exhaust is tested in a fixture to ensure perfect fitment and then foam packed to arrive in perfect condition, ready to install with no cutting or modifying required.

LIFETIME WARRANTY:  Enjoy your SOUL exhaust components with confidence on both the street and track as the valves and entire exhaust are covered by a Lifetime Warranty! Our team will quickly work with you to resolve any issues or answer any questions that you may have.

NOTE: O2 bungs can be added (to work with aftermarket headers that relocate the bungs to the SMB). We do not add them by default in the interest of lightness. Contact us for this option.


  1. Rashed Al Mulla

    Weight savings:
    Confirmed on the scale, solid weight loss of the rear of the car as advertised.

    Reduced heat:
    This was VERY noticeable as soon as I removed the side mufflers and installed the valved bypass pipes. The engine compartment is WAY cooler after a long drive compared to when I had the side mufflers on the car. Very Impressed with this .
    Tire pressures are more stable in the rear as well ( due to reduced heat in the back I believe).

    I’ll be honest here, nothing to notice in regards to power gains ( I did not dyno the car as I wasn’t looking for gains anyways).

    FANTASTIC ! I’m running the car with race headers ( catless) and it is absolutely addictive. In normal mode it sounds tame , no drone at all and can be driven daily without annoying anyone ( perhaps 20% louder than stock) . Sport mode is a different story lol ! The closest thing is ( if I wanted to describe how it sounds in words) would be a 997 cup car. Really aggressive, heel toe is way more pronounced compared to the stock setup and throttle blips just rip.
    Really satisfied with this aspect. I would easily say this is the BEST exhaust solution for a GT3 if you are looking for sound + weight saving.

    Quality and packaging:
    Professional packaging , really nice quality and welds on the bypass pipes as well.

    If you can put together Legos, you can install the bypass pipes on the car.

    Really satisfied with the purchase John, two thumbs up !

  2. KPJ (Rennlist)

    All, some additional feedback on a 997.2 GT3 with recently installed Soul valved side muffler bypass. Wasn’t too hard to do at home, without a lift & with the rear bumper removed. After doing it, I wouldn’t even attempt it without removing the bumper unless you have a lift. The only hassle I had was with the horrible deformed torque prevailing nuts that Porsche use on the side pipe to centre muffler joints, and that’s nothing to do with the Soul kit. I’ve been modifying cars myself for 20 odd years and I have to say the quality of the Soul valved SMB’s is brilliant. I was concerned, as I’ve never dealt with a fully hard mounted exhaust before, but the dimensional accuracy of the Soul parts was spot on.Now to the sound. I do have drone around 2500rpm, which I was surprised about given some prior comments indicating that there was no drone with the Soul SMB’s, though I can’t imagine any SMB from different companies being any better. I think it’s just an inevitable downside when you ditch those huge standard side mufflers. It’s not unlivable drone like I’ve had in modified Supra’s before, but I would however still like to do a back to back vs other GT3’s with different modified exhausts just to check. Drone aside, I can’t overstate how amazing the thing sounds now above 3500rpm. It surprised me a bit actually as I thought that above 3500rpm once the valves are open on the stock exhaust and more or less bypassing the side mufflers that the sound would be more or less the same, but it isn’t, it’s much better. Unlike many on this forum that think Mezger’s sounds amazing even in stock form, I don’t, give me a GT350 Voodoo for sound any day of the week. Does the car sound as great as a Voodoo 5.2 now? No, but jeeze it’s close. It’s a completely different sound, but sounds like an exotic supercar above 3500rpm, and below 3500rpm when the closed side valves made it sound asthmatic with the stock exhaust, it now sounds like a proper performance car should.
    For anyone like me that’s spending a lot of time trying to decide on whether to go SMB or CMB, and which brand, all I can say is that having forked over what I consider to be a decent chunk of cash for the Soul SMB’s, I would absolutely do the same again if I got a stock GT3 tomorrow.

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