SOUL Performance Valved Side Muffler Bypass Pipes for 997 Porsche 911 GT3 and GT3 RS
A 3-inch T304L stainless side-muffler swap with factory-style valves that cuts 35.4 pounds and gives the flat-six a quiet-to-loud second voice, with the factory center muffler kept in place.
These items are typically not in stock and either made-to-order or special order from the manufacturer. After you order we will confirm the estimated lead time and other order details. If you have a specific deadline to receive this order please talk to us before placing your order to ensure that the manufacturer can meet your expectations.
This item and any similar items are not CARB approved and therefore not for sale in the state of California or other states that require CARB certification. No assessment is being made regarding this product's compliance with the EPA's anti tampering policy, only that the necessary testing and validation has not been completed. Please check with your local enforcement officials regarding legality of use in your place of residence.
The Valved Side Muffler Bypass Pipes from SOUL Performance give the 997 Porsche 911 GT3 and GT3 RS a real second voice, louder and sharper on command and civil the rest of the time, by replacing the heavy factory side mufflers with 3-inch stainless pipes and SOUL’s own valves that operate just like the car’s factory system. SOUL hand-builds them in Willow Grove, Pennsylvania from mandrel-bent T304L stainless steel with high-quality flex bellows, fixture-tests every set, and backs the original owner, valves included, with a lifetime materials and workmanship warranty for street and track use. They keep the factory center muffler in place for a smooth, usable transition between quiet and open, strip 35.4 pounds from the rear of the car, and bolt on without cutting. For the GT3 owner who wants valve-controlled sound and a serious weight cut, this is the considered way to do it.
Design and Performance
By retaining the factory center muffler and adding their own valves, these pipes deliver a smoother transition between open and closed than a center muffler bypass; with the valves closed the car is only moderately louder and stays comfortable on the road, and with them open the flat-six takes on a higher-pitched, more aggressive note. An enlarged crossover equalizes pressure so the factory center muffler keeps doing its job, and the 3-inch primary piping opens up flow over the restrictive factory side mufflers.
Construction
SOUL mandrel-bends the pipes from T304L stainless steel and fits high-quality flex bellows for durability and a precise, rattle-free installation, and the valves are built to operate like the factory system so the stock controls still govern the exhaust. Every set is assembled, fixture-tested for fitment, and foam-packed so it arrives ready to bolt on without cutting or modifying the car.
Features
Replace the factory side mufflers with 3-inch stainless pipes and SOUL valves that operate like the factory system
Keep the factory center muffler in place, with an enlarged crossover to equalize pressure
High-quality flex bellows for durability and a precise fit
Smoother open-to-closed valve transition than a center muffler bypass
Moderately louder with the valves closed, higher-pitched and aggressive with them open
Major rear weight reduction over the heavy factory side mufflers
O2 bungs available on request for aftermarket headers that relocate the sensors
Direct bolt-on, no cutting required
Lifetime warranty to the original owner, valves included
Level-2 install difficulty (bolt-on; rear bumper removal and a lift are advised)
Specifications
Material: T304L stainless steel
Piping diameter: 3 inches
Wall thickness: 0.065 inches
System weight: 9.5 lbs
Factory components: 44.9 lbs
Weight reduction: 35.4 lbs (16 kg)
What’s Included
A pair of valved side muffler bypass pipes with integrated valves
High-quality flex bellows
Mounting hardware
Printed installation instructions
Applications
Porsche 911 GT3: 997.1 | 2007-2009 | 3.6L F6
Porsche 911 GT3: 997.2 | 2010-2011 | 3.8L F6
Porsche 911 GT3 RS: 997.1 | 2007-2009 | 3.6L F6
Porsche 911 GT3 RS: 997.2 | 2010-2011 | 3.8L F6
Notes
These pipes replace the factory side mufflers and retain the factory center muffler; the enlarged crossover equalizes pressure so the center muffler keeps doing its job
SOUL’s valves operate like the factory system, so you keep quiet, usable running with them closed and a louder, higher-pitched note with them open
O2 bungs are not included by default and can be added on request for aftermarket headers that relocate the sensors
Some owners report mild drone in a narrow rpm band. With the valves closed and the factory center muffler in place, the car stays comfortable day to day.
This system increases exhaust volume; it is intended for off-road and track use and may not be legal where exhaust-noise limits apply
Frequently Asked Questions
Will the Valved Side Muffler Bypass Pipes fit my 997 GT3? Yes. The Valved Side Muffler Bypass Pipes fit the 997.1 and 997.2 Porsche 911 GT3 and GT3 RS from 2007 to 2011, with the 3.6L flat-six on the 997.1 and the 3.8L on the 997.2. They are a direct bolt-on that replaces the factory side mufflers, with no cutting required.
Do the valves work with the factory controls? Yes. SOUL builds the valves to operate like the factory system, so the car’s stock controls still open and close them. You keep a quiet, usable exhaust with the valves closed and a louder, higher-pitched note with them open, which keeps the GT3 livable day to day.
How is this different from the center muffler bypass? These pipes replace the factory side mufflers and keep the factory center muffler, and they add their own valves for a smoother open-to-closed transition. The center muffler bypass does the opposite, replacing the center muffler and keeping the factory valved side mufflers. They are two different approaches to the same car, not meant to be combined.
How loud is it, and will it drone? With the valves closed it is only moderately louder than stock and stays comfortable; with them open it gains a higher-pitched, aggressive edge. Some owners report mild drone in a narrow rpm band, but keeping the factory center muffler in place makes this one of the more usable options for the street.
What are the Valved Side Muffler Bypass Pipes made from? They are mandrel-bent from 3-inch T304L stainless steel with a 0.065-inch wall, fitted with high-quality flex bellows and SOUL’s own factory-style valves. SOUL backs the original owner with a lifetime warranty on materials and workmanship, valves included, for street and track use.
Are they a direct bolt-on? Yes. They bolt on in place of the factory side mufflers with no cutting, and most owners do the job with the rear bumper removed and the car on a lift. Watch the factory prevailing nuts at the side-pipe-to-center-muffler joints, as Porsche torques them hard.
About SOUL Performance
SOUL Performance Products was founded by a group of automotive enthusiasts with deep industry experience and a commitment to doing right by their customers. Their mission is to deliver outstanding performance parts at fair pricing, backed by quality service and one of the best warranties in the industry. SOUL develops high-performance exhaust systems and components that are engineered for exceptional sound and proven performance, with products ready to ship quickly worldwide. Guided by core values of honesty, transparency, and passion for cars, they build strong community connections and prioritize customer satisfaction at every step. Operating out of a dedicated facility in Willow Grove, Pennsylvania, SOUL combines hands-on research, engineering, and manufacturing expertise to create parts that meet and exceed the demands of serious enthusiasts.
Additional Information
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Shipping Policy
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Items that are in stock in the US, either at Bulletproof’s warehouse or at a supplier’s warehouse, are generally delivered within 7-10 days. Special order items from overseas take considerably longer. As a courtesy Bulletproof offers delivery estimates to our customers which take into consideration manufacturer availability and shipping schedule. These estimates represent our best guess based on previous orders from the manufacturer and do not in any way imply a guaranteed delivery window. Many manufacturers work in a “just in time” inventory system and often take 2-20+ weeks to produce an item once an order is submitted. All deliverable items are then sent to our Japanese warehouse. Bulletproof ships a minimum of one full ocean freight container every month from Japan, oftentimes more than one a month. Ocean freight takes an average of 4 weeks. Typically it breaks down to one week in Japan for paperwork and customs, two weeks by boat and one week in US customs/clearance. Due to the wide number of variables between manufacturer and shipping schedules, delivery estimates are simply just that – estimates. We attempt to estimate conservatively and we usually deliver faster than our estimates suggest. It is not Bulletproof’s policy to guarantee delivery time of any special order item, this is impossible for us to do. By ordering you acknowledge that there is no required delivery ETA and an order may not be canceled or altered due to manufacturing or shipping delays, all ETA’s are provided as a best guess only. Please review the full Terms & Conditions here.
BP Pricing Difference
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We do pricing a little differently on our JDM brands and we believe in making things simple and clear. No hidden fees or surcharges. Every price you see includes the shipping cost to our office in Los Angeles, California and all the associated taxes/duties/fees for bringing the products into the US. The only shipping you ever pay is from our facility in the US to your location. Be wary of resellers that don’t include the cost of international shipping in their pricing on JDM parts. While we believe we’ll always have the lowest all-in price on JDM products, we offer a price match guarantee for all authentic parts purchased from authorized dealers as well.
For many international customers, it’s much more affordable to ship from the USA than from Japan directly, as the air freight and ocean freight costs are typically much less. However, for customers looking to ship directly from Japan outside of North America, or domestically in Japan, we can provide pricing specifically for that scenario. Please do not hesitate to contact us with any pricing questions or concerns. Please email us at sales@bulletproofautomotive.com with any inquiries.
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