Light Weight Hollow Rear Torsion Bars, Tubular. Porsche 911/912 1965-86  ❭  RT11

QuickChange™ Torsion Bars, REAR
Sold per kit, 1 kit req'd per car.



Fits:
Porsche 911/912/930/914 '65-'86
Porsche 356 A/B '48-'65 (Pre-A, C and CS Read Notes),
Porsche 944/968/924 '76-'95 w/ QuickChange Spring Plates

PLEASE NOTE: sizes 34mm and 36mm are not applicable for 944, 968 and 924 models)

QuickChange Torsion Bars are Plated & Plugged and include a female threaded end that you can engage with a bolt to use as a handle for easier extraction / insertion.

Use the rears bars in combination with our QuickChange™ Spring Plate products for fast torsion bar swapping and re-indexing. QuickChange™ Torsion Bars can be extracted through the QuickChange™ Spring Plate without removing any bolts. Alignment settings are maintained. You don't even need to remove the wheel from the car. Changing torsion bars is a 5 minute per side operation!

A QuickChange™ Insert is available separately for converting your existing hollow torsion bars.

QuickChange™ Torsion Bars make it easy to dislodge a stuck bar, and thereby offer benefits even when used on the front and with factory spring plates (factory spring do not allow the bars to be extracted without removing the plates).

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

21020

The product you are viewing cross references to these numbers

High-performance Sway-A-Way solid rear torsion bar set for Porsche 924 and Porsche 944 models. Available in sizes from 23 mm through to 30 mm, these torsion bars allow the rear suspension spring rate to be tailored to suit anything from a road-focused sports car through to a dedicated track or competition build.
SET OF 2, One pair is required per vehicle.

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

  * Note: For Porsche 944 Turbo, S2 and other higher-performance variants, always check the original rear torsion-bar specification before selecting a replacement rate, as some models were equipped with larger factory bars.


The Porsche 924 and 944 rear suspension uses torsion bars as its primary springing medium. As the suspension moves, the torsion bar twists along its axis, providing the spring force required to support and control the rear of the vehicle.

Increasing the torsion-bar diameter increases resistance to twisting and therefore raises the effective rear spring rate. The result can be reduced body roll, less rear-end squat under acceleration and more precise suspension control during fast cornering.

Sway-A-Way manufactures these bars using solid high-strength alloy steel, with heat treatment and precision centreless grinding to provide consistent dimensions, predictable spring characteristics and long-term durability.

Available Torsion Bar Sizes

  23 mm Solid   (Standard / Mild Upgrade)

The 23 mm solid rear torsion bar is the mildest option in this range and is well suited to road cars where improved suspension control is required without moving immediately to a very stiff performance setup.

Recommended for:
 •  Road use
 •  Mild suspension upgrades
 •  Touring cars
 •  Restoration and refresh projects
 •  Cars where ride compliance remains important

Critical Fitment Exceptions:
Even if your car falls into the year ranges above, verify these specific exclusions:
•   Porsche 944 Turbo / S2: Performance models often utilize a different factory diameter and may require a larger upgrade (25mm+) to see a noticeable handling benefit.
•   Spring Plate Compatibility: Ensure your spring plate bushings are in good condition. A 23mm bar is roughly 25% stiffer than a stock 22mm bar, which increases the load on your rubber or urethane bushings.

 24 mm Solid   (Sport / Street Upgrade)

The 24 mm solid rear torsion bar provides a modest increase in rear spring rate and offers a useful balance between road comfort and improved chassis response.

Recommended for:
•   Road and fast-road use
•   Weekend sports cars
•   Uprated dampers
•   Mild performance builds
•   Occasional spirited driving

Critical Fitment Exceptions:
Even if your car falls into the year ranges above, you must ensure it does not fall under these exceptions:
•   Porsche 944 Turbo / S2: These performance-oriented Porsche models often came with larger factory bars (25.5mm+); installing a 24mm bar would actually be a downgrade in stiffness.
•  Significant Stiffness Increase: A 24mm bar is roughly 40% stiffer than a stock 22mm bar. This upgrade is highly recommended for autocross or spirited street driving but may require upgraded shock valving to control the increased rebound speed.

  25 mm Solid

The 25 mm solid torsion bar provides a more noticeable increase in rear suspension stiffness. It is a strong choice for performance road cars and occasional track use where reduced body movement and sharper chassis response are priorities.

Recommended for:
•  Fast-road builds
•  Occasional track days
•  Uprated dampers
•  Performance tyres
•  Modified suspension setups

  26 mm Solid   (Competition / Heavy-Duty Upgrade)

The 26 mm solid rear torsion bar moves further toward a dedicated performance setup, providing substantially increased resistance to rear suspension compression.

Recommended for:
•  Fast-road / track cars
•  Autocross
•  Higher-powered Porsche 944 models
•  Uprated dampers
•  High-grip tyres
•  Performance suspension packages

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 bar is approximately 95% stiffer than a factory 22mm bar. This results in a very rigid ride quality. For street-driven cars, this may be excessively harsh without professional-grade dampers.
•  Shock Absorber Compatibility: You must pair these bars with performance-valved shocks. Standard street shocks will be unable to control the high rebound energy of a 26mm bar, potentially leading to "pogo" handling.

  27 mm Solid

The 27 mm solid rear torsion bar is a serious performance upgrade. It provides greater roll stiffness and reduced rear-end squat, making it well suited to track-focused and competition-inspired Porsche 924 / 944 builds.

Recommended for:
•  Track days
•  Autocross
•  Motorsport-inspired cars
•  High-performance road builds
•  Cars with appropriately matched 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 Solid  (Extreme Competition / Heavy-Duty)

The 28 mm solid rear torsion bar provides a high spring rate intended primarily for more focused performance and competition applications.

Recommended for:
•  Dedicated track cars
•  Competition builds
•  High-grip tyre packages
•  Lightweight cars
•  Performance or race-valved dampers

At this level, the complete suspension setup should be considered rather than changing the rear spring rate in isolation.

Critical Fitment & Safety Warnings
Before installing, please verify these high-performance requirements:
•   Extreme Stiffness: A 28mm bar is roughly 160% stiffer than a factory 22mm bar. This results in an incredibly rigid ride quality that may be unsuitable for regular street use without reinforced chassis mounts.
•   Damper Compatibility: You must pair these with high-end, race-valved adjustable shocks (e.g., Koni Sport or Bilstein B8). Standard street shocks cannot control the high rebound energy of a 28mm bar, which can cause dangerous handling and "pogoing."

  29 mm Solid  (Extreme Competition / Heavy-Duty)

The 29 mm solid torsion bar is an extreme performance option intended for highly developed track and competition vehicles. This solid Sway-A-Way bar excels in demanding applications, including performance versions of the Porsche 944 Turbo and S2 models.

Recommended for:
•  Competition cars
•  High-power track builds
•  Motorsport
•  Very high-grip tyres
•  Race-valved dampers
•  Highly developed chassis setups

Critical Fitment & Safety Warnings
Before installing, please verify these high-performance requirements:
•  Race-Only Stiffness: A 29mm bar is roughly 200% stiffer than a factory 22mm bar. This results in an incredibly rigid ride quality that is generally unsuitable for street use and may cause chassis fatigue without reinforced mounting points.
•  Damper Compatibility: You must pair these with high-end, race-valved adjustable shocks. Standard street shocks cannot control the massive rebound energy of a 29mm bar, which can cause dangerous handling and "pogoing."

  30 mm Solid   (Ultimate Competition / Heavy-Duty)

The 30 mm solid rear torsion bar is the stiffest solid option in this range. Designed primarily for competition applications, it provides very high resistance to body roll and rear suspension compression.

Recommended for:
•  Dedicated race cars
•  Motorsport applications
•  High-power Porsche 944 builds
•  Competition tyres
•  Race suspension systems

Applications where maximum chassis control takes priority over road comfort

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 a 30mm bar. The rebound energy will be violent and dangerous without high-end, race-valved adjustable dampers (e.g., Koni Yellow or Bilstein B8/Cup).
•  Street Use: This setup will be punishingly stiff on public roads and is generally reserved for dedicated track or off-road competition use.


Why Upgrade the Rear Torsion Bars?

Larger rear torsion bars can provide:
•    Reduced body roll
•    Reduced rear-end squat
•    Improved rear suspension control
•    Faster chassis response
•    Better support for performance tyres
•    Increased stability during hard cornering
•    Improved track performance

The larger the torsion-bar diameter, the higher the spring rate and the firmer the suspension will become.

Solid Construction

These Sway-A-Way torsion bars use traditional solid alloy-steel construction.

 Solid torsion bars offer:
•    High torsional strength
•    Excellent durability
•    Predictable spring characteristics
•    Proven suspension technology
•    Wide range of available spring rates
•    Excellent value compared with hollow alternatives
•    Suitability for road and motorsport use

For owners who prioritise spring-rate selection and durability over the weight saving offered by tubular bars, the solid range provides an excellent suspension upgrade.

Precision Manufacturing

Sway-A-Way specifies:
•    High-strength alloy steel
•    Heat treatment
•    Precision centreless grinding
•    Consistent outside diameter
•    Controlled spring characteristics
•    Protective powder coating

These processes are designed to provide consistent suspension behaviour while improving fatigue resistance and durability.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

RS12

The product you are viewing cross references to these numbers

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.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

RT12

The product you are viewing cross references to these numbers