Does this fit both the GT3 and GT3 RS?

Yes. The pipes fit the 991.1 Porsche 911 GT3 and GT3 RS from 2014 to 2016, covering the 3.8-liter flat-six in the GT3 and the 4.0-liter flat-six in the GT3 RS. They are for the 991.1 generation and do not fit the later 991.2 GT3 or GT3 RS.

What do the Fabspeed Side Muffler Bypass Pipes do?

The Fabspeed Side Muffler Bypass Pipes replace the heavy, restrictive factory side mufflers with free-flowing 14 to 16 gauge T304 stainless pipes, cutting 34 lbs and giving the GT3 an aggressive Cup-car sound. They include relocated O2 bungs so the oxygen sensors keep working, and they bolt on without cutting.

What is the difference between the valved and non-valved versions?

The valved version uses Fabspeed Helical valves wired to the factory Porsche Sport Exhaust control, so the car can stay quieter on the closed setting and open up on demand. The non-valved version runs permanently open for the loudest, most direct sound. Choose the valved option to keep the PSE function.

How much power and weight does it change?

Fabspeed reports gains of about 12 horsepower and 10 lb-ft from the freer flow, and the pipes remove 34 lbs from the car. On a GT3 RS tested with the Rennsport muffler, peak output rose from 446 to 454 wheel horsepower, so the two work well together.

Do they keep the oxygen sensors working?

Yes. Fabspeed moves the O2 bungs from the header collector onto these pipes, so the oxygen sensors sit in the right place and keep reading correctly, which matters when the car also runs long-tube headers. They bolt on using the factory mounting points.

Are these street legal?

Fabspeed does not state a CARB certification for these side muffler bypass pipes, and removing the factory side mufflers increases sound. Street-legality depends on where the car is registered and used, so confirm local noise and emissions rules before fitting them. The valved option is the quieter choice.

Description

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BP PRICING DIFFERENCE

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Description

Fabspeed Side Muffler Bypass Pipes for 991.1 Porsche 911 GT3 & GT3 RS

The Fabspeed Side Muffler Bypass Pipes for the 991.1 Porsche 911 GT3 & GT3 RS are engineered to enhance both performance and sound. Featuring the highest quality Helical valves, these pipes save 34lbs from the rear of the vehicle while replicating the aggressive CUP car sound for a thrilling street experience. Constructed from durable 14-16 gauge T304 stainless steel, they ensure optimal flow and longevity. With a simple bolt-on installation process, upgrading your GT3 or GT3 RS has never been easier, delivering improved performance and an unmistakable exhaust note.

Helical Valves

Fabspeed chose to use Helical Valves in their 991 GT3 / GT3 RS track exhaust systems for their exceptional quality, which has been proven by numerous OEM manufacturers such as McLaren, Ferrari, Lamborghini, and others. These valves are a key component of Fabspeed’s Side Muffler Bypass pipes, opening and closing with precision to control gas flow and optimize engine back-pressure for enhanced performance. Helical’s extensive experience in high-volume OEM automotive applications has led to features such as a highly durable pneumatic actuator, precision flat sealing faces inside the valve, stiffening ribs, and high-temperature bearings at both ends of the butterfly spindle.

02 Bungs

Fabspeed relocated the O2 bungs from the collector of the headers to the Side Muffler Bypass Pipes to maintain factory-like functionality with their Long Tube Competition Headers, ensuring that all cylinders are read while optimizing the performance of the collector. This design replaces the existing SMBPs, allowing for a seamless upgrade to the Long Tube Race Header design at any time in the future.

Features

Highest quality Helical valves
Saves 34lbs from the rear of the vehicle
Replicates aggressive CUP car sound for the street
14-16ga T304 stainless steel construction
Simple bolt-on installation
Includes O2 bungs for factory like functionality
All Fabspeed performance products are backed by the Fabspeed lifetime warranty

Applications

Porsche 911 GT3: 991.1 | 2014-2016 | 3.8L Flat-Six
Porsche 911 GT3 RS: 991.1 | 2015-2016 | 4.0L Flat-Six

Notes

All Fabspeed products are expected to ship within one week of order, though timelines are often much quicker
To retain PSE functionality please select the valved option upon checkout
Installation instructions for Porsche homelink connection

Frequently Asked Questions

Does this fit both the GT3 and GT3 RS? Yes. The pipes fit the 991.1 Porsche 911 GT3 and GT3 RS from 2014 to 2016, covering the 3.8-liter flat-six in the GT3 and the 4.0-liter flat-six in the GT3 RS. They are for the 991.1 generation and do not fit the later 991.2 GT3 or GT3 RS.
What do the Fabspeed Side Muffler Bypass Pipes do? The Fabspeed Side Muffler Bypass Pipes replace the heavy, restrictive factory side mufflers with free-flowing 14 to 16 gauge T304 stainless pipes, cutting 34 lbs and giving the GT3 an aggressive Cup-car sound. They include relocated O2 bungs so the oxygen sensors keep working, and they bolt on without cutting.
What is the difference between the valved and non-valved versions? The valved version uses Fabspeed Helical valves wired to the factory Porsche Sport Exhaust control, so the car can stay quieter on the closed setting and open up on demand. The non-valved version runs permanently open for the loudest, most direct sound. Choose the valved option to keep the PSE function.
How much power and weight does it change? Fabspeed reports gains of about 12 horsepower and 10 lb-ft from the freer flow, and the pipes remove 34 lbs from the car. On a GT3 RS tested with the Rennsport muffler, peak output rose from 446 to 454 wheel horsepower, so the two work well together.
Do they keep the oxygen sensors working? Yes. Fabspeed moves the O2 bungs from the header collector onto these pipes, so the oxygen sensors sit in the right place and keep reading correctly, which matters when the car also runs long-tube headers. They bolt on using the factory mounting points.
Are these street legal? Fabspeed does not state a CARB certification for these side muffler bypass pipes, and removing the factory side mufflers increases sound. Street-legality depends on where the car is registered and used, so confirm local noise and emissions rules before fitting them. The valved option is the quieter choice.

About Fabspeed

Fabspeed Motorsport is situated in Fort Washington, Pennsylvania, within the United States of America. Their extensive 26,000 sqft. facility serves as a hub for various car clubs, including Porsche Club of America, Ferrari, McLaren, Lamborghini, and more. The company is renowned for its comprehensive approach to product development. They handle the entire process, from design and engineering to dyno testing, street trials, and racing assessments, ensuring the quality and performance of every item. Fabspeed also collaborates closely with race engine builders and tuners hailing from Italy, Germany, and the United States, resulting in the creation of the Ultimate Performance parts. To cater to their passionate global audience, Fabspeed meticulously crafts systems using aerospace-grade austenitic stainless steel, titanium, and carbon fiber materials, setting a standard for excellence in the industry.

Additional Information

The Bulletproof Automotive website contains many thousands of products purchased in multiple different currencies. All of the prices are entered manually and accurately at the time of entry. Due to the consistently fluctuating international exchange rates, at times prices may not be able to be honored at their original intended rate. We apologize for any inconvenience this may cause, unfortunately our website is unable to compensate dynamically for what can at times be volatile changes in the cost of items due to currency values fluctuating, changes in prices from suppliers, changes in shipping and import duties, and other factors. Rest assured that any order you place on line will be at zero risk to you in this area. If in the event your order cannot be fulfilled at the original intended website price we will offer you a 100% refund, no questions asked. We will continue to do our best to maintain updated prices and we will always continue to offer our price match guarantees as well to ensure our prices are always the best for you. In short, prices may change without notice. It is always advised to give us a call prior to placing your order online to confirm availability and to confirm current pricing.

Shipping Policy

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

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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Fabspeed Side Muffler Bypass Pipes for 991.1 Porsche 911 GT3 & GT3 RS [FS.POR.991GT3.SMBX]

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Fabspeed Side Muffler Bypass Pipes for 991.1 Porsche 911 GT3 & GT3 RS

Helical Valves

02 Bungs

Features

Applications

Notes

Frequently Asked Questions

About Fabspeed

Reviews