Fabspeed Muffler Bypass Zork Tube. Porsche 911 Turbo 930 (1976-1989)  ›  FSPOR911TZMB

Fabspeed Muffler Bypass Zork Tube. 

The Fabspeed Porsche 911 Turbo 930 Muffler Bypass Zork Tube is a motorsport-inspired performance exhaust upgrade designed for Porsche 911 Turbo (930) models manufactured between 1976 and 1989.

Fits:

• Porsche 911 1976-1977 3.0L Turbo (930)
• Porsche 911 1978-1989 3.3L Turbo (930)  

Developed by Fabspeed Motorsport, this high-flow exhaust component replaces the factory rear muffler arrangement with a short, large-diameter exhaust outlet that connects directly to the turbocharger and exits beneath the rear bumper.

Inspired by the exhaust configuration of the legendary Porsche 934 IMSA racing car, the Zork Tube delivers an aggressive competition exhaust sound while reducing exhaust restriction downstream of the turbocharger.

Manufactured from high-quality T304 stainless steel, the tube features precision mandrel-bent construction, 3.0-inch (76 mm) diameter tubing and an integrated angle-cut exhaust outlet.

Its lightweight design weighs less than 5 lb (approximately 2.3 kg), making it a significantly lighter alternative to a conventional rear muffler arrangement.

By reducing exhaust backpressure, the Fabspeed Zork Tube is designed to improve exhaust gas flow, enhance turbocharger response and deliver a more immediate, engaging driving experience.

Fabspeed advertises performance gains of up to 46 wheel horsepower and 65 lb-ft of torque, based on testing under specific vehicle and environmental conditions.

The Zork Tube also produces an exceptionally loud and distinctive exhaust note, allowing the characteristic turbocharger whistle, spool-up sounds and air-cooled flat-six exhaust character to become more pronounced.

Unlike a conventional sports muffler, this component prioritises exhaust flow, lightweight construction and competition performance rather than sound suppression.

The direct-fit design allows the tube to bolt to the compatible factory turbocharger outlet, providing a straightforward solution for enthusiasts building a Porsche 930 with a historic racing-inspired exhaust configuration.

Ideal for dedicated motorsport vehicles, competition preparation and track-focused Porsche 930 projects, the Fabspeed Zork Tube combines lightweight stainless steel construction with unmistakable Porsche racing heritage.

Important: This is an extremely loud competition-style exhaust product. It is not intended as a conventional road-going muffler replacement and must only be used where applicable emissions and noise regulations permit.

What This Product Does:
The Fabspeed Zork Tube provides a short, direct exhaust route from the turbocharger to the rear of the vehicle.

By eliminating the conventional rear muffler arrangement, it allows exhaust gases to exit through a substantially less restrictive pipe.

Its key functions and benefits include:

• Reduced Exhaust Backpressure: Removes the flow restriction associated with the original rear muffler arrangement.
• Improved Exhaust Gas Flow: Provides a large-diameter outlet for exhaust gases leaving the turbocharger.
• Enhanced Turbocharger Response: Reduced downstream restriction may help the turbocharger respond more quickly.
• Reduced Turbo Lag: Fabspeed markets the Zork Tube as a performance solution designed to improve turbocharger response.
• Increased Horsepower Potential: Manufacturer-advertised gains of up to 46 wheel horsepower under the tested conditions.
• Improved Torque Potential: Manufacturer-advertised gains of up to 65 lb-ft.
• Aggressive Motorsport Exhaust Sound: Produces a loud, unsilenced exhaust note inspired by Porsche competition cars.
• Enhanced Turbocharger Whistle: Makes turbocharger spool-up and operating sounds more noticeable.
• Lightweight Exhaust Design: Weighs less than 5 lb, reducing the weight of the replacement exhaust section.
• Large-Diameter Tubing: Uses 3.0-inch (76 mm) tubing for high-flow exhaust routing.
• Durable Stainless Steel Construction: T304 stainless steel provides resistance to corrosion and high exhaust temperatures.
• Mandrel-Bent Pipework: Helps maintain consistent tubing diameter and smooth exhaust flow.
• Historic Motorsport Styling: Features a Porsche 934 IMSA-inspired exhaust arrangement.
• Direct Bolt-On Installation: Connects to the appropriate turbocharger outlet without requiring a conventional rear muffler.

Symptoms Of Wear Or Failure:
The Fabspeed Zork Tube is primarily a motorsport performance upgrade rather than a standard replacement or fault-repair component.

However, owners may consider replacing or refurbishing original exhaust components when deterioration, damage or excessive restriction has been identified.

Common symptoms include:

1. Exhaust Corrosion

The original exhaust muffler and associated pipework may develop corrosion due to moisture, road salt and repeated heating and cooling cycles.

Advanced corrosion can weaken the metal and lead to exhaust leaks or mounting failures.

2. Exhaust Leaks

Cracked exhaust sections, damaged flanges or deteriorated gaskets may allow exhaust gases to escape before reaching the intended outlet.

Symptoms can include blowing noises, visible soot deposits and exhaust fumes.

3. Internal Muffler Damage

Ageing exhaust mufflers can develop loose internal baffles or deteriorated components.

This may produce rattling, metallic noises or unwanted changes in exhaust sound.

4. Restricted Exhaust Flow

A damaged or obstructed exhaust component may increase backpressure and affect the engine's ability to expel exhaust gases.

Severe restrictions can influence turbocharger operation and engine performance.

5. Reduced Turbocharger Response

Excessive downstream exhaust restriction may contribute to slower turbocharger response.

However, poor boost response may also be caused by boost leaks, wastegate faults, turbocharger wear or incorrect engine tuning.

6. Damaged Exhaust Mountings

Corroded brackets, damaged fasteners or weakened mounting points may allow the exhaust to move excessively.

This can lead to vibration, rattling or unwanted contact with surrounding bodywork.

7. Excessive Exhaust Vibration

Loose exhaust connections or damaged mountings can produce unusual vibration, particularly during acceleration and changes in engine speed.

8. Visible Exhaust Damage

Impact damage, crushed pipework or distorted mounting flanges may compromise the integrity of the original exhaust system.

9. Exhaust Fumes or Unusual Odours

An exhaust leak may allow harmful gases to escape near the engine compartment or passenger cabin.

Any suspected exhaust leak should be investigated immediately because exhaust gases can contain carbon monoxide.

10. Deteriorated Exhaust Connections

Damaged sealing surfaces, corroded turbocharger fasteners or worn gaskets may prevent secure exhaust connections.

Why Replacement / Upgrading Matters:

• Upgrading to the Fabspeed Zork Tube provides a distinctive competition-focused exhaust configuration for the Porsche 911 Turbo 930.
• The original Porsche exhaust system was designed to balance engine performance, noise control, emissions requirements and everyday usability.
• For dedicated motorsport applications, a shorter and less restrictive exhaust path may offer performance and weight-saving advantages.

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