Light Weight Hollow Rear Torsion Bars, Tubular. Porsche 924 / 944  ❭  RT12

High-performance Sway-A-Way tubular rear torsion bar set for Porsche 924 and Porsche 944 models. Available in rates from 25 mm through to 31 mm, these lightweight tubular torsion bars allow the rear suspension of the Porsche 924 or 944 to be tailored for fast-road, track-day and motorsport applications.
SET OF 2, One pair is required per vehicle.

Fits:
Porsche 924 1977 - 1988
Porsche 944 1982 - 1991

  * Note: For Porsche 944 Turbo, Turbo S, S2 and other higher-performance models, always confirm the original suspension specification before selecting a replacement rate.


Designed as a lightweight performance replacement for the original rear torsion bars, these hollow bars provide the spring rate associated with the stated solid torsion-bar size while reducing overall component weight.

The Porsche 924 and 944 use torsion bars as the primary rear suspension springs. As the suspension moves, each torsion bar twists along its axis, generating the spring force required to support and control the rear of the vehicle.

Increasing the torsion-bar rate increases resistance to suspension movement, helping to reduce body roll and rear-end squat while providing more precise chassis control during acceleration, braking and cornering.

Sway-A-Way's tubular construction is particularly attractive for performance-focused Porsche builds because the internal diameter is engineered so that the hollow bar provides the intended spring rate while using less material than the equivalent solid bar.

 The result is a high-performance torsion bar offering an excellent combination of spring-rate control, strength and reduced weight.

Available Tubular Torsion Bar Rates

  25 mm Tubular  (High-Performance Street/Track)

The 25 mm tubular rear torsion bar is the mildest option in this hollow-bar range. It offers increased suspension control while retaining greater road usability than the larger competition-oriented sizes.

Recommended for:
•  Performance road cars
•  Fast-road Porsche 924 / 944 builds
•  Uprated dampers
•  Occasional track-day use
•  Drivers wanting a lightweight torsion-bar upgrade.

This is particularly suitable for cars where improved rear control is wanted without moving immediately to an extremely stiff track setup.

Critical Fitment Exceptions:
Even if your vehicle falls into the year ranges above, you must verify it does not meet these specific exceptions:
•  Porsche 944 Turbo / S2: These high-performance models often left the factory with 25.5mm bars. Installing a 25mm bar would be a slight downgrade in stiffness.
•  Performance Tuning: A 25mm bar is roughly 65% stiffer than a factory 22mm bar. While the tubular design reduces weight, the ride will be significantly firmer. We highly recommend pairing these with performance-valved shocks to manage the increased spring frequency.

 26 mm Tubular   (Competition / Weight Reduction)

The 26 mm tubular torsion bar provides a substantial increase in rear spring rate while maintaining the weight advantage of hollow construction.

Recommended for:
•  Fast-road / track-day cars
•  Autocross
•  Performance Porsche 944 builds
•  Higher-grip tyre packages
•  Cars equipped with performance-valved dampers

The increased rate helps control suspension compression and rear-end movement during aggressive driving.

Critical Fitment Exceptions
Even if your vehicle falls into the year ranges above, you must verify it does not meet these specific exceptions: 
•  Extreme Stiffness Warning: A 26mm spring rate is approximately 95% stiffer than a factory 22mm bar. Even with the weight savings of a tubular design, the ride will be very rigid.
•  High-Performance Dampers Required: Standard street shocks cannot control the high rebound energy of a 26mm bar. You must pair these with performance-valved or adjustable shocks to avoid dangerous "pogo" handling.

  27 mm Tubular   (Extreme Performance / Weight Reduction)

The 27 mm tubular rear torsion bar moves firmly into track-focused suspension territory. It provides significantly greater resistance to rear suspension movement and is ideal for performance builds where chassis response takes priority over standard ride comfort.

Recommended for:
•  Regular track days
•  Autocross
•  High-performance Porsche 944 builds
•  Turbo / S2 performance applications
•  High-grip tyres
•  Appropriately valved performance dampers

Critical Fitment Exceptions
Even if your vehicle falls into the year ranges above, you must verify it does not meet these specific exceptions: 
•  Competition Stiffness Warning: A 27mm spring rate is over 125% stiffer than a factory 22mm bar. This setup is strictly recommended for track-dedicated vehicles or professional-grade competition builds.
•  Advanced Damping Required: Standard street shocks cannot control the high rebound energy of a 27mm bar. You must pair these with race-valved or adjustable shocks (such as Koni Sport or Bilstein B6/B8) to avoid dangerous handling characteristics.

  28 mm Tubular   (Extreme Competition / Weight Reduction)

The 28 mm tubular torsion bar provides a high rear spring rate for serious performance applications.

Recommended for:
•  Track-focused Porsche 924 / 944 builds
•  Competition-inspired cars
•  Lightweight track cars
•  High-grip tyre packages
•  Performance or competition dampers

Critical Fitment Exceptions
Even if your vehicle falls into the year ranges above, you must verify it does not meet these specific exceptions: 
•  Extreme Stiffness Warning: A 28mm spring rate is over 160% stiffer than a factory 22mm bar. Even with the weight savings of a tubular design, the ride will be incredibly rigid.
•  Advanced Damping Required: Standard street shocks cannot control the high rebound energy of a 28mm bar. You must pair these with race-valved or adjustable shocks (e.g., Koni Sport or Bilstein B8) to avoid dangerous "pogo" handling.

At this level, the front and rear suspension should be considered together to maintain the intended chassis balance.

  29 mm Tubular  (Extreme Competition / Weight Reduction)

The 29 mm tubular rear torsion bar is aimed primarily at highly developed track and competition vehicles.

Recommended for:
•  Dedicated track cars
•  Motorsport
•  High-power Porsche 944 Turbo builds
•  High-grip competition tyres
•  Race-valved dampers
•  Fully developed suspension packages

This rate represents a major increase in rear suspension stiffness and is generally most appropriate when road comfort is a secondary consideration.

Critical Fitment & Safety Warnings
Before installing, please verify these high-performance requirements:
•  Race-Only Stiffness: A 29mm spring rate is over 200% stiffer than a factory 22mm bar. Even with the weight savings of a tubular design, the ride will be incredibly rigid and may cause chassis fatigue without reinforced mounting points.
•  Advanced Damping Required: Standard street shocks cannot control the massive rebound energy of a 29mm bar. You must pair these with race-valved or adjustable shocks (e.g., Koni Sport or Bilstein B8) to avoid dangerous "pogo" handling.

 30 mm Tubular   (Ultimate Competition / Weight Reduction)

The 30 mm tubular rear torsion bar provides an extremely high spring rate combined with the reduced weight of hollow construction.

Recommended for:
•  Dedicated race cars
•  Motorsport applications
•  High-output Porsche 944 builds
•  Competition suspension systems
•  Race tyres
•  Professionally developed chassis setups

Appropriately matched dampers are essential when using a torsion bar of this rate.

Critical Fitment & Safety Warnings
Because a 30mm bar is over 250% stiffer than a factory 22mm bar, please verify these requirements:
•  Chassis Stress: This level of rigidity exerts immense force on the chassis. We highly recommend reinforced torsion housings and heavy-duty spring plates to prevent metal fatigue or cracking.
•  Mandatory Damper Upgrade: Standard street shocks cannot control the massive rebound energy of a 30mm bar. You must pair these with race-valved or adjustable shocks (e.g., Koni Sport or Bilstein B8) to avoid dangerous "pogo" handling.
•  Street Use: This setup will be punishingly stiff on public roads and is generally reserved for dedicated track or off-road competition use.

 31 mm Tubular  (Ultimate Competition / Maximum Weight Savings)

The 31 mm tubular rear torsion bar represents the most aggressive option in this range. Designed for highly developed motorsport applications, this rate is intended for vehicles where maximum suspension control takes priority over road compliance.

Recommended for:
•  Dedicated competition cars
•  Motorsport
•  High-grip race tyres
•  Lightweight race builds
•  High-power applications
•  Competition dampers
•  Professionally engineered suspension packages

Professional chassis setup is strongly recommended when moving to this level of rear spring stiffness.

Critical Fitment & Safety Warnings
This is a specialized racing component. Please verify the following before installation:
• Extreme Rigidity: A 31mm spring rate is over 290% stiffer than a factory 22mm bar. This setup is strictly for dedicated track vehicles or professional-grade competition. It will be punishingly stiff for street use.
• Advanced Damping Required: You must pair these with race-valved, high-pressure gas shocks (e.g., Bilstein Cup or Koni Race). Standard street shocks cannot control the high rebound energy of a 31mm bar, which can lead to dangerous "pogo" handling.
• Chassis Reinforcement: Due to the massive torque these bars exert on the rear suspension carrier, we highly recommend inspecting and reinforcing your torsion housing and using heavy-duty spring plates.

Important Fitment Information

These bars use the 26 9/16-inch long rear torsion-bar configuration.

Always verify: Torsion-bar length,  Spline count,  Original spring rate,  Vehicle model,  Suspension specification before ordering.

Some Porsche 944 performance models were equipped with comparatively large factory torsion bars, so choosing a smaller replacement may not result in an increase in rear spring rate.


Tubular Construction

Sway-A-Way tubular torsion bars are designed to provide the required spring rate while removing material that is not necessary to achieve that rate.

The internal diameter is calculated so the hollow bar provides the spring characteristics associated with the equivalent solid torsion-bar size.

This means the tubular design is principally a weight-saving solution, rather than a softer version of the same diameter bar.

Sway-A-Way states that its tubular Porsche 924 / 944 bars can save approximately 5 lb per set compared with equivalent solid versions.

Benefits include:
•  Reduced suspension component weight
•  Equivalent target spring rate to the corresponding solid bar
•  High torsional strength
•  Excellent fatigue resistance
•  Performance-oriented construction
•  Ideal for lightweight road and competition builds.

Precision Manufacturing

Sway-A-Way tubular torsion bars are manufactured using high-strength alloy steel and a performance-focused production process

Construction includes:
•  Tubular aircraft-grade alloy steel
•  Heat treatment
•  Through-hardening
•  Shot peening
•  Precision centreless grinding
•  Controlled dimensions
•  Powder-coated corrosion protection

These processes help provide predictable spring characteristics and durability under repeated high-load suspension movement.

Why Upgrade Rear Torsion Bars?

The rear torsion bars determine a major part of the Porsche 924 / 944 rear spring rate.

Increasing the torsion-bar rate can provide:
•  Reduced body roll
•  Reduced rear-end squat
•  Improved chassis response
•  Better suspension control
•  Greater stability during fast cornering
•  Improved support for performance tyres
•  More consistent behaviour during track driving

The larger the stated torsion-bar rate, the greater the suspension stiffness.

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RT12

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