Fabspeed Sport Headers. Porsche 991 GT3 Cup (2017 +)  ›  FSPOR991CUPSHDR

The Fabspeed Porsche 991 GT3 Cup Sport Headers are a high-performance replacement for the restrictive factory exhaust headers fitted to Porsche 991 GT3 Cup race cars from 2017 onward.

Fits:

• Porsche 991 GT3 Cup 2017-2019

Designed specifically for competition-focused GT3 Cup applications, these headers improve exhaust gas flow and scavenging, helping the naturally aspirated flat-six engine breathe more efficiently throughout the rev range.

The system features one-piece CNC mandrel-bent primary header tubes, a high-velocity motorsport-style merge collector and specially designed inlet flanges. Fabspeed manufactures the system from a combination of T321 and T304 stainless steel for strength, corrosion resistance and durability under extreme exhaust temperatures.

Integrated German-made HJS 200-cell tri-metallic sport catalytic converters provide substantially increased exhaust flow compared with more restrictive factory catalysts while retaining catalytic treatment.

Fabspeed lists a performance gain of up to approximately 15 HP, although actual output will vary according to vehicle specification, setup and operating conditions. The system also removes approximately 1 kg / 2 lb from the rear of the vehicle compared with the factory arrangement.

What This Product Does:
The exhaust headers collect combustion gases as they leave the engine's individual cylinders and direct them into the remainder of the exhaust system.

On a high-revving GT3 Cup engine, efficient exhaust flow is especially important because the engine must move large volumes of exhaust gas at high RPM.

The Fabspeed Sport Headers are designed to:

• Reduce exhaust restriction.
• Improve exhaust gas velocity.
• Improve cylinder scavenging.
• Reduce pumping losses.
• Support stronger high-RPM performance.
• Improve throttle response.
• Increase potential horsepower.
• Maintain efficient exhaust flow during sustained track use.
• Reduce unnecessary weight at the rear of the vehicle.
• Provide high-flow catalytic treatment through HJS sport catalysts.

Possible symptoms of worn or damaged headers include:

• Ticking or tapping noise from the exhaust area.
• Exhaust note becoming louder than normal.
• Exhaust gases leaking near the cylinder heads.
• Soot marks around header flanges.
• Cracks in the header tubing.
• Cracked welds.
• Distorted mounting flanges.
• Loose mounting hardware.
• Failed exhaust gaskets.
• Rattling from the catalytic converter area.
• Reduced throttle response.
• Loss of high-RPM performance.
• Increased exhaust backpressure.
• Engine-management warning lights.
• Catalyst-efficiency fault codes.
• Unusual exhaust smells.
• Excessive heat around nearby components.

Because GT3 Cup vehicles are subjected to sustained competition use, regular inspection of the exhaust system is particularly important.

Why Replacement / Upgrading Matters:
A GT3 Cup engine depends on efficient airflow at both the intake and exhaust sides of the combustion process.

Restrictive, cracked or damaged headers can reduce the efficiency with which exhaust gases leave the engine.

Replacing worn components or upgrading to a higher-flow header system can help restore or improve:

• Exhaust gas flow.
• Cylinder scavenging.
• Engine responsiveness.
• High-RPM power delivery.
• Exhaust sealing.
• Thermal management.
• Competition reliability.
• Overall exhaust-system efficiency.

For a race car, maintaining predictable performance across repeated high-load sessions is especially important.