SOUL Long Tube Street Headers. Porsche 981 GT4 / Boxster Spyder / Clubsport › POR.GT4.STH

The SOUL Performance Long Tube Street Headers are high-performance aftermarket exhaust manifolds developed specifically for the Porsche 981 Cayman GT4, Boxster Spyder and GT4 Clubsport models manufactured between 2015 and 2016.

Fits:

• Porsche Boxster 981 Spyder 3.8L 2016
• Porsche Cayman GT4 3.8L 2015-16  

The original Porsche exhaust system is designed to balance performance, emissions, noise restrictions and everyday usability.

SOUL Performance's long-tube headers are designed to improve exhaust flow and engine response by using longer, smoother exhaust runners and optimised collectors.

Each header assembly features 2-inch primary runners, smooth-radius tubing and port-matched mounting flanges to help exhaust gases flow efficiently from the cylinder heads.

The headers are constructed from T304L stainless steel, providing excellent corrosion resistance and durability under demanding exhaust operating conditions.

High-flow catalytic converters are incorporated into the system, allowing improved exhaust flow while retaining a catalytic treatment stage rather than adopting a fully decatted design.

The long-tube configuration is particularly beneficial on a high-revving naturally aspirated engine because exhaust gas velocity, pulse timing and collector design influence engine breathing and the delivery of power across the rev range.

SOUL Performance has developed this product to complement the characteristics of the Porsche 981 GT4 and Spyder's 3.8L engine.

The result is a performance-focused exhaust upgrade intended to improve throttle response, enhance high-RPM engine performance and produce a more pronounced flat-six exhaust note.

Unlike a complete exhaust replacement, these headers replace the exhaust manifold and catalyst sections while allowing the compatible downstream exhaust to remain in place.

The product is manufactured using precision fabrication methods and is checked in a dedicated fixture to maintain accurate installation fitment.

SOUL Performance supplies installation instructions and offers a manufacturer's lifetime warranty, subject to its published conditions.

Ideal for Porsche enthusiasts seeking improved engine response, stronger performance and a more engaging exhaust character, these Long Tube Street Headers provide a substantial upgrade to the factory exhaust manifold arrangement.

What This Product Does:
The exhaust headers collect combustion gases leaving the engine's cylinder heads and direct them into the remainder of the exhaust system.

In a naturally aspirated flat-six engine, the design of the exhaust runners and collectors can influence how efficiently exhaust gases leave the cylinders.

Reducing unnecessary restrictions and improving exhaust pulse behaviour can help the engine expel spent gases and prepare for the next intake and combustion cycle.

The SOUL Performance Long Tube Street Headers are designed to improve this process through their runner length, primary diameter and collector geometry.

Their main functions include:

• Collecting exhaust gases: Direct exhaust gases away from the engine's cylinder heads.
• Improving exhaust flow: Use smooth-radius tubing and optimised collectors to reduce unnecessary restrictions.
• Supporting exhaust scavenging: Help exhaust pulses travel through the runners in a more efficient manner.
• Improving throttle response: Support more responsive engine behaviour under acceleration.
• Increasing performance potential: Enable improved engine breathing, particularly at higher engine speeds.
• Enhancing exhaust sound: Produce a stronger, more distinctive flat-six exhaust character.
• Maintaining catalytic treatment: Incorporate high-flow catalytic converters in the exhaust path.
• Supporting high-RPM operation: Use runner and collector dimensions selected for the 3.8L GT4 engine.
• Maintaining downstream exhaust compatibility: Connect to the appropriate existing rear exhaust system.
• Providing durable exhaust construction: Use corrosion-resistant stainless steel designed for elevated temperatures.
• Supporting performance tuning: Provide improved exhaust flow that may complement a correctly developed ECU calibration.
• Enhancing driving engagement: Deliver a more pronounced engine response and soundtrack.
  
  

The upgrade is intended to improve exhaust efficiency, increase engine responsiveness and enhance the naturally aspirated Porsche flat-six soundtrack.

Improved Exhaust Flow

• The long-tube runners, smooth-radius bends and optimised collectors are designed to improve the movement of exhaust gases away from the cylinder heads.
• This helps reduce unwanted restrictions within the header assembly and supports more efficient engine breathing.

Increased Performance Potential

• SOUL Performance developed these headers specifically for the 3.8L engine used in the 981 Cayman GT4 and Boxster Spyder.
• The manufacturer reports independent Dyno Dynamics testing showing approximately 30 whp of improvement in a tuned configuration, including 12 whp of additional gain from the headers when tested after tuning.
• These results reflect the particular test vehicle and configuration. Individual results will vary.

Sharper Throttle Response

• Improved exhaust flow can contribute to more responsive engine behaviour, particularly when accelerating through the middle and upper engine speed ranges.

Enhanced Flat-Six Exhaust Sound

• The header design changes how exhaust gases travel through the system.
• This can produce a fuller, more pronounced and more sporting exhaust note.
• The final sound depends on whether the vehicle uses the original Porsche rear exhaust or another compatible aftermarket system.

High-Flow Catalytic Converter Design

• The integrated catalytic converters allow a performance-focused exhaust arrangement without removing the catalytic treatment stage entirely.
• Nevertheless, the manufacturer does not certify the product for all emissions-controlled road applications.

Stainless Steel Durability

• T304L stainless steel offers corrosion resistance and durability under repeated heating and cooling cycles.

Factory-Style Installation

• SOUL Performance designs these headers as a direct bolt-on replacement for the corresponding original exhaust manifold arrangement.
• No bespoke exhaust fabrication is advertised for a standard compatible installation, although access and removal of corroded hardware can make the work demanding.

Long-Term Performance Upgrade

• For Porsche owners seeking greater performance and a more distinctive driving experience, these headers offer an upgrade to a major part of the engine's exhaust system.

The product may also complement suitable ECU tuning and other performance exhaust modifications.