Fabspeed Rennsport Muffler System for 991.1 Porsche 911 GT3 & GT3 RS [FS.POR.991GT3.RSMXX]
$4,836.95
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Fabspeed Rennsport Muffler System for 991.1 Porsche 911 GT3 & GT3 RS
A stronger CNC-cut T304L stainless replacement for the crack-prone OEM muffler, with a cast X-pipe and 2.75-inch valve-open tubing. 50-state legal, keeps PSE, choice of tip finish.
Fabspeed Rennsport Muffler System for 991.1 Porsche 911 GT3 & GT3 RS
As many GT3 owners are aware, the OEM mufflers are prone to cracking, breaking, and blowing out, especially the titanium mufflers on GT3RS models. Fabspeed set out to design a muffler replacement that addresses these issues while improving on the OEM design. Drawing on over 25 years of experience with both air- and water-cooled engines, Fabspeed increased the valve open tubing to 2.75 inches (70mm), which is the optimal diameter for GT3 engines to ensure low restriction, high velocity, and a high-pitched GT3 sound reminiscent of the GT3 CUP car. Additionally, Fabspeed incorporated their signature investment-cast X-pipe for optimal exhaust scavenging, merging the two cylinder banks without restricting exhaust flow. To maintain the factory muffler’s exhaust note and eliminate drone, Fabspeed replicated Porsche’s 7-chamber design, resulting in a completely drone-free system, even when paired with race headers. When combined with Fabspeed’s Side Muffler Muffler Bypass Pipes, this exhaust system delivers the ultimate emissions-compliant GT3 exhaust. This muffler is guaranteed to never break or fail.
Sound
This muffler produces a tone similar to the OEM muffler, but with a slightly louder sound when the PSE is turned on. It also delivers a smoother, higher-pitched tone, enhanced by Fabspeed’s signature X-pipe.
Power
On Fabspeed’s 991.1 GT3RS test car, when paired with the Side Muffler Bypass Pipes, the Rennsport Muffler delivered an impressive increase of 27ft/lbs of torque at 3,200rpm. From 2,900rpm to 5,700rpm, it gained 10 whp or more, with peak whp rising from 446 to 454. This results in an 8whp or 9hp gain at the crank.
Features
Constructed from CNC cut T304L stainless steel
Designed from 3D scans of the OEM muffler to achieve perfect bolt-on fitment
Incorporates our signature cast X-pipe for superior flow and exhaust scavenging
All Fabspeed products are expected to ship within one week of order, though timelines are often much quicker
Exhaust system is designed to reuse OEM gaskets and hardware
Frequently Asked Questions
Does this fit both the GT3 and GT3 RS? Yes. The muffler fits 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. It is for the 991.1 generation and does not fit the later 991.2 GT3 or GT3 RS.
What is the Fabspeed Rennsport Muffler System made from? The Fabspeed Rennsport Muffler System is CNC-cut from T304L stainless steel, built from 3D scans of the factory muffler with 2.75-inch valve-open tubing, an investment-cast X-pipe, and a seven-chamber design that mirrors the OEM layout. It bolts on and keeps the factory Porsche Sport Exhaust valve function.
Why replace the factory muffler? The OEM 991 GT3 muffler is prone to cracking and blow-outs over time, and it restricts flow. The Rennsport muffler replaces it with a stronger CNC-cut stainless unit that flows better, sounds smoother and higher-pitched, and stays drone-free, while retaining the factory valve function and a 50-state-legal cat-back design.
Is it emissions legal, and will it set a check engine light? Yes. The Rennsport muffler is a cat-back system that is emissions legal in all 50 states, and Fabspeed guarantees no check engine light. It retains the factory Porsche Sport Exhaust valve function and reuses the OEM gaskets and hardware, so it installs as a clean bolt-on.
How much power does it add? On a 991.1 GT3 RS paired with Fabspeed’s Side Muffler Bypass Pipes, Fabspeed measured peak output rising from 446 to 454 wheel horsepower, with 10 or more wheel horsepower gained from 2,900 to 5,700 rpm and 27 lb-ft at 3,200 rpm. Those figures reflect the muffler and bypass pipes together.
Will it drone on the highway? No. The seven-chamber design and X-pipe are tuned to cancel drone, so the car stays comfortable at a cruise, and Fabspeed reports it remains drone-free even alongside its race headers. With PSE on it is a bit louder, with a smoother, higher-pitched note than stock.
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
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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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