BBiAutosport

White Porsche 991 GT3 BBi StreetCup Exhaust Bypass Installation Process







Shedding weight is one of simplest ways to add performance to your Porsche. Unfortunately, reducing weight on the already slim GT3 is rarely an inexpensive task and the factory exhaust system is already very well designed for optimum power delivery. The only drawbacks to the factory system is a muted exhaust note that was designed to comply with the local laws and appeal to a wide customer base, and the excess weight.

We addressed those flaws when we designed our exhaust system for the 997 GT3. Most other aftermarket exhaust systems on the market replaces the secondary center muffler and the performance gains and weight savings are minimal. The factory secondary exhaust weights approximately 20 pounds and the average secondary muffler bypass weighs approximately 7 pounds, which equates to only 13 pounds of weight savings.

We took a more unorthodox approach and bypassed the much heavier primary side mufflers. The primary mufflers are weigh approximately 44 pounds total while our bypass pipes are 4 pounds in comparison. For durability and protection against corrosion, each system is meticulously TIG welded using 304 aerospace grade stainless tubing with lower carbon content. The result is a substantial reduction in weight behind the rear axle which significantly improves handling and less restriction to produce a much more aggressive exhaust note.

One of the most commonly asked questions that we receive is about the installation process of our BBi 991 GT3 Exhaust System.
Can it be done at home? Can it be installed without removing the bumper?

Due to the size of the side mufflers, removal of the bumper is required and the installation time is approximately 3 hours. To mitigate the risks of damaging the bumper or brackets, we highly recommend professional installation at our facility or our recommended dealers. To help show what is involved, we documented the installation process step by step from start to finish below:

Bumper removed


Rear Heatshield removed




Side heatshield removed


Side muffler removed




Stock vs BBi Street Cup. 40lb Savings




BBi Side muffler bypass installed











Bumper reinstalled



BBi Autosport Porsche 991 GT3 / GT3RS StreetCup Exhaust Bypass



Inspired by Porsche’s motorsport program, the Street Cup name represents the culmination of our winning experience in professional motorsports and the extensive R&D efforts with our in-house fabrication, suspension engineering, and engine development programs. All of the experience gained with our successful racing background combined with state-of-the-art materials and the highest quality manufacturing have yielded an upgrade package worthy of the Porsche name.

Key Features

• Delivers deep aggressive exhaust sound
• Significant weight reduction of 40 pounds
• 304 stainless steel aerospace tubing
• Meticulously TIG welded
• Brushed stainless finish
• Stainless hardware and clamps
• 100% emissions legal
• Will not void warranty
• Factory secondary mufflers and catalytic converters are all retained
• 50 state emission compliant
• Direct bolt on replacement
• Compatible with 991 GT3 and 991 GT3RS models
• Made in USA

For all questions or to place an order, please email us at Jerry@BBiAutosport.com or Sales@BBiAutosport.com
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BBiAutosport

Video and review:


Link to Review:
https://rennlist.com/forums/991-gt3/...ound-clip.html

911_RS

Nice! How much is it? Will it loose torque just like they said?

BBiAutosport

It will lose a very small amount of torque but the gains outweigh the cons here.

You will shed 40 pounds of weight behind the rear axles, enhance the sound, and make a few horses at the top end.

I will send you pricing information via PM

- Jerry@BBiAutosport.com

hfm

Sounds like you've done a before and after dyno. Could we see the chart please.

Spyerx

On my 997 with the same setup you lose a tick of low end below 3k rpm torque. Under 10ftlbs IIRC? All made up before 3.5k. I can't find my dyno graph. I could not feel this with the butt dyno.
However, if you're driving a GT3 under 3k, you're not in the right gear. Especially with PDKS you have no excuse.
It does make power in the top end and sounds sweet.
You're doing this to remove weigh & heat from the rear end of the car. And the killer sound.