Porsche 991.1 / 991.2 GT3 / GT3 RS / 911R SOUL Side Muffler Bypass Pipes

$1,495.00

Product Description

The SOUL Side Muffler Bypass Pipes are a lightweight, non-valved exhaust upgrade for Porsche 991.1 and 991.2 GT3 / GT3 RS models and the 911R, replacing the heavy factory side mufflers with large-diameter 3-inch stainless-steel bypass pipes while retaining the factory center muffler.

The factory side-muffler assemblies weigh approximately 44.9 lbs, while the complete SOUL bypass system weighs only approximately 6.6 lbs, removing an impressive 38.3 lbs / 17.3 kg from the rear of the vehicle.

In addition to the substantial weight reduction, deleting the side mufflers reduces heat retention around the engine bay and rear tires. Large-diameter 3-inch piping increases exhaust flow, while integrated flex bellows provide compliance for thermal expansion and aggressive track use.

Unlike SOUL's Valved Side Muffler Bypass, this system is permanently non-valved. There is no selectable quiet mode—the exhaust delivers its freer-flowing, race-derived character at all times.

FITMENT:

• Fits 2014–2016 Porsche 991.1 911 GT3

• Fits 2016 Porsche 991.1 911 GT3 RS

• Fits 2016 Porsche 911R

• Fits 2018–2019 Porsche 991.2 911 GT3

• Fits 2018–2019 Porsche 991.2 911 GT3 with Touring Package

• Fits 2019 Porsche 991.2 911 GT3 RS

• SOUL specifies fitment for all Porsche 991.1 / 991.2 GT3 and GT3 RS models including the 911R from 2014–2019

• Retains the factory center muffler

• Replaces the factory side mufflers

• Compatible with the factory header and catalytic-converter system

• Direct bolt-on installation

DETAILS:

• Non-valved Side Muffler Bypass Pipe system

• Deletes both factory side mufflers

• Retains the original Porsche center muffler

• Permanently freer-flowing exhaust configuration

• No selectable valves-open / valves-closed sound modes

• Large-diameter 3-inch primary piping

• Constructed from mandrel-bent T304L stainless steel

• .065-inch wall thickness

• High-quality flex bellows incorporated into the system

• Flex bellows simplify installation and accommodate component movement

• Flex bellows help reduce stress during repeated heat cycles and aggressive track use

• Enlarged opening into the secondary center-muffler path

• Secondary-path design helps equalize pressure within the retained factory center muffler

• Pressure balancing is intended to reduce stress on the factory center muffler

• Significantly reduces rear exhaust-system weight

• Helps reduce heat soak in the engine bay

• Helps reduce exhaust-system heat transferred toward the rear tires

• SOUL system weighs approximately 6.6 lbs / 3.0 kg

• Factory side-muffler components weigh approximately 44.9 lbs / 20.4 kg

• Saves approximately 38.3 lbs / 17.3 kg

• No cutting required

• No welding required

• No permanent exhaust modification required

• Every system is fixture-tested for proper fitment

• Designed and built in-house by SOUL Performance Products in Willow Grove, Pennsylvania

• Backed by SOUL's Lifetime Warranty for street and track use

WHY DELETE THE SIDE MUFFLERS?

The factory GT3 exhaust uses substantial side-muffler assemblies that contribute considerable weight and retain heat in the rear of the vehicle.

SOUL replaces those components with compact 3-inch stainless-steel bypass pipes.

The result is a significant reduction in:

• Exhaust-system weight

• Rear vehicle mass

• Engine-bay heat retention

• Heat accumulation near the rear tires

while retaining the factory center muffler to help control overall sound character.

38.3-LB WEIGHT REDUCTION:

Weight savings are one of the primary reasons to choose the non-valved Side Muffler Bypass.

Factory Side-Muffler Components:
Approximately 44.9 lbs / 20.4 kg

SOUL Side Muffler Bypass Pipes:
Approximately 6.6 lbs / 3.0 kg

Total Weight Savings:
Approximately 38.3 lbs / 17.3 kg

This removes nearly 40 lbs from the extreme rear of a rear-engined 911 without requiring replacement of the factory headers or center muffler.

HEAT MANAGEMENT:

Factory mufflers retain considerable thermal energy after extended high-load operation.

Removing the large side mufflers reduces the amount of hot exhaust hardware surrounding the rear of the vehicle.

SOUL specifically identifies two benefits:

• Reduced engine-bay heat soak

• Reduced heat exposure around the rear tires

These benefits become increasingly relevant during repeated track sessions where exhaust temperatures remain elevated for extended periods.

3-INCH PRIMARY PIPING:

The Side Muffler Bypass uses:

3-inch-diameter primary piping

constructed from:

.065-inch-wall T304L stainless steel

The larger-diameter path reduces the restriction created by the original side-muffler assemblies and provides substantial exhaust-flow capacity for the naturally aspirated GT engine.

RETAINS THE FACTORY CENTER MUFFLER:

This system removes the side mufflers, not the center muffler.

The original Porsche center muffler remains installed and continues to contribute acoustic attenuation.

This creates a fundamentally different sound character than a Center Muffler Bypass.

The configuration combines:

• Lightweight side-muffler deletion

• Increased exhaust flow

• Reduced rear heat

• Retained center-muffler sound control

• Permanently non-valved operation

NON-VALVED DESIGN:

Unlike SOUL's Valved Side Muffler Bypass, this version eliminates the exhaust-valve functionality associated with the side-muffler assemblies.

There is:

• No electronic or vacuum-controlled exhaust valve

• No driver-selectable quiet mode

• No factory valves-open / valves-closed transition

• No additional valve hardware

The system provides its performance-oriented exhaust path continuously.

This makes the non-valved version particularly attractive for customers prioritizing:

• Minimum weight

• Simplicity

• Maximum consistency

• Track use

• Constant exhaust character

SOUND CHARACTER:

SOUL describes the Side Muffler Bypass as increasing overall volume without introducing undesirable tonal characteristics.

Expect:

• Increased naturally aspirated flat-six presence

• Greater cabin sound

• More race-derived exhaust character

• More exotic tone

• Increased mechanical character

• Stronger high-RPM sound

• Particularly dramatic exhaust character above 5,000 RPM

SOUL specifically notes increased cabin presence in approximately the:

2,000–3,000 RPM range

Above approximately:

5,000 RPM

the system increasingly emphasizes the GT engine's high-RPM exhaust character.

CABIN PRESENCE:

Because this is a permanently non-valved system, customers should expect more exhaust presence inside the vehicle than with the factory exhaust or SOUL's valved version.

SOUL specifically identifies increased cabin presence around:

2,000–3,000 RPM

This is an important consideration for vehicles primarily used for long-distance street driving.

Drivers who want the ability to substantially reduce exhaust presence on demand should consider the Valved Side Muffler Bypass instead.

CENTER-MUFFLER PRESSURE MANAGEMENT:

The SOUL bypass pipes retain a secondary flow path into the factory center muffler.

SOUL enlarges the opening leading into this secondary section to help equalize pressure within the center muffler.

This is designed to:

• Improve pressure distribution

• Reduce localized loading

• Reduce stress on the factory center muffler

• Lower the likelihood of center-muffler cracking

This is particularly important because removing the factory side mufflers substantially changes the exhaust-flow architecture upstream of the retained center muffler.

FLEX BELLOWS:

High-quality flex bellows are incorporated into the bypass pipes.

The flex sections provide compliance for:

• Thermal expansion

• Engine movement

• Exhaust-system movement

• Manufacturing tolerances

• Chassis movement

• Repeated track heat cycles

SOUL specifically incorporates the bellows to simplify installation and help prevent cracking under extreme racing conditions.

SIDE MUFFLER BYPASS VS. VALVED SIDE MUFFLER BYPASS:

Non-Valved Side Muffler Bypass

• $1,495.00

• Permanently non-valved

• Approximately 6.6 lbs

• Approximately 38.3 lbs lighter than factory

• 3-inch primary piping

• Maximum simplicity

• Lowest weight

• Constant performance exhaust character

• No quiet mode

Valved Side Muffler Bypass

• $2,095.00

• Retains selectable exhaust-valve functionality

• Approximately 9.5 lbs

• Approximately 35.4 lbs lighter than factory

• 3-inch primary piping

• Allows quieter and louder operating modes

• Better suited to customers wanting additional street flexibility

The non-valved system saves an additional 2.9 lbs compared with the Valved Side Muffler Bypass while eliminating the exhaust-valve hardware entirely.

SIDE MUFFLER BYPASS VS. CENTER MUFFLER BYPASS:

Side Muffler Bypass

• Removes both factory side mufflers

• Retains the factory center muffler

• Approximately 38.3 lbs of weight savings

• Major reduction in rear exhaust heat

• 3-inch performance piping

• More exotic / race-derived sound character

• Permanently non-valved

Center Muffler Bypass

• Removes the factory center muffler

• Retains factory side mufflers

• Retains factory exhaust valves

• Approximately 11 lbs of weight savings

• More dramatic driver-controlled sound change

• Better sound-control flexibility

Customers primarily focused on weight reduction and heat management will gain considerably more from the Side Muffler Bypass.

WITH FACTORY HEADERS:

When paired with the original Porsche headers, the vehicle retains its factory:

• Catalytic converters

• Oxygen sensors

• Header assemblies

while replacing only the side-muffler assemblies.

This configuration provides:

• Major weight reduction

• Reduced rear exhaust heat

• Increased exhaust flow

• Increased sound

• Retained factory center muffler

WITH UPGRADED HEADERS:

The Side Muffler Bypass can also form part of a more aggressive exhaust configuration using higher-flowing aftermarket headers.

Changing the headers can substantially increase:

• Overall exhaust volume

• High-RPM intensity

• Exhaust-flow capability

• Engine character

• Track-oriented sound

Customers should confirm compatibility with the specific header and oxygen-sensor configuration being used.

DIRECT BOLT-ON INSTALLATION:

The Side Muffler Bypass Pipes are designed as a direct bolt-on replacement for the factory side mufflers.

SOUL specifically states that installation requires:

• No cutting

• No modification

Each assembly is built and tested in a fixture to ensure proper fitment before being packaged for shipment.

PERFORMANCE:

The combination of large 3-inch piping and elimination of the factory side mufflers increases available exhaust-flow capacity.

SOUL does not publish a controlled standalone horsepower or torque figure for these Side Muffler Bypass Pipes.

DasMotoring therefore does not advertise a specific power gain.

The primary verified benefits are:

• 38.3 lbs of weight reduction

• Reduced engine-bay heat soak

• Reduced rear-tire heat exposure

• Increased exhaust flow

• Increased exhaust sound

EXHAUST TIPS:

This standalone product does not require a tip selection.

The Side Muffler Bypass Pipes replace the side-muffler section while retaining the factory center-exhaust architecture.

There are therefore no:

• Tip-style variants

• Tip-finish variants

• Catalyst variants

• Valve variants within this product

EMISSIONS / USE NOTE:

SOUL specifies that this product is not CARB certified and may not be legal for use on emissions-controlled vehicles.

SOUL lists the product as intended for off-road use only.

Customers are responsible for determining compliance with applicable federal, state, and local regulations before installation or use.