Table of contents
How do you improve the fastest and most capable car in a model range? With the Porsche Cayman GT4 RS suspension upgrades detailed below, your car will generate more cornering grip, unlock additional braking stability, and accelerate out of turns with enhanced poise and precision.
With the following GT4 RS upgrades, your car will also communicate its behaviour with greater clarity, which we know is something Porsche enthusiasts crave.
In this GT4 RS suspension upgrade guide, we’ll cover the stock car’s handling flaws and reveal the best ways to fix them using Suspension Secrets upgrades.
Cayman GT4 RS Overview
Debuting in the winter of 2021, the Porsche GT4 RS is based on the 718-series Cayman chassis but features a multitude of performance enhancements.
Behind occupants lurks a sensational, naturally aspirated, flat-six powerplant that also found a home in the 991 GT3 R and RSR. Linked to a seven-speed PDK transmission and revving to 9,000rpm, the output of the four-litre engine is rated at 500hp with 450Nm of torque, which are 80hp and 30Nm up on the GT4 respectively. These figures provide a 0-60mph time of 3.2 seconds (GT4 with PDK: 4.2 seconds) as well as a 196mph top speed (GT4: 189mph).
More extreme aerodynamics allow the GT4 RS to generate up to 25 per cent more downforce than the GT4 (100kg at 124mph), while reduced sound deadening material in the cabin plus carbon fibre reinforced plastic front wings and bonnet save 35kg.
In terms of suspension, the GT4 RS is equipped with the same MacPherson strut front and multi-link rear design as the GT4, although its springs are stiffer and Bilstein dampers firmer. There are also solid ball joints in more places on the GT4 RS to ramp up feel and response.
The result is a Porsche that laps the infamous Nürburgring Nordschleife in just 7min 9.30secs or a whole 23.6secs faster than the GT4.
However, this is only the beginning. Read on to discover which Porsche GT4 RS suspension upgrades make the biggest difference to handling performance, overall feel, and of course lap times…
Suspension & Handling Problems (And How to Fix Them)
The Porsche Cayman GT4 RS suspension has a wider adjustment window than most other cars, however it's still not a perfect setup.
Main problems
- Front end push/understeer
- Oversprung and underdamped rear axle
- Limited camber and toe adjustment (front and rear)
- Nose diving under heavy braking
- Rear skipping under throttle on corner exit
- Excessive front tyre wear during high speed driving
These issues stop the GT4 RS from handling at its absolute best, but leave the door open for signifiant gains after suspension upgrades.
The most effective fixes are:
- Increasing front camber to reduce understeer & improve tyre wear
- Adjusting toe angle to enhance traction and stability
- Decreasing rear spring rate and increase front spring rate
- Correcting suspension geometry with a professional alignment
With all these suspension changes carried out, the GT4 RS will realise its true potential on the road and track.
Suspension Geometry & Alignment Setup (Top Tip)
A full suspension geometry alignment is essential after installing new suspension parts.
By correctly adjusting camber, toe, and caster (where available), alignment ensures you maximise grip, stability, and tyre life.
Benefits of Proper Cayman GT4 RS Geometry Setup
- Sharper steering response
- Increased cornering grip
- Improved rear traction
- Enhanced braking stability
- More consistent tyre wear
Essential Suspension Upgrades for Porsche Cayman GT4 RS
These are the most effective and cost-effective suspension upgrades for the Porsche Cayman GT4 RS. These parts form the foundation of all Suspension Secrets handling packages and represent a perfect first step in your upgrade journey.
Camber Caster Plate Top Mounts
Up to -2.4 degrees of front camber is achievable on the stock Porsche Cayman GT4 RS suspension, however this is not enough if you're driving hard on track.
Adjustable camber plates from Suspension Secrets allow more negative camber to be dialled into the front axle, significantly increasing front-end grip and improving turn-in response.
Why Camber Plates Matter on the Cayman GT4 RS
- Reduce understeer
- Sharpen turn-in
- Increase steering feedback
- Improve tyre wear on track
Suspension Secrets' GT4 RS adjustable front top mounts/camber plates also feature 2 degrees of positive caster angle, improving steering feel and providing dynamic camber gain as steering lock is applied. These camber plates are fully compatible with OEM dampers and PASM, too.
Adjustable Rear Toe Arms
So you've reduced understeer with the front top mounts mentioned above, which allow more negative camber to be dialled into the GT4 RS's chassis. Now it's time to increase the amount of adjustability on the rear axle to further improve cornering grip as well as overall chassis response and predictability.
Although the GT4 RS's factory toe arms offer more adjustment than those fitted to the Cayman GT4, their range is still relatively limited and compromises a performance-oriented setup which relies on additional camber. As rear camber is increased to improve cornering grip, it becomes impossible to achieve the toe-in necessary for truly enhanced corner-exit stability and traction.
Suspension Secrets Adjustable Rear Toe Arms offer:
- Greater adjustment range than OEM arms
- Independent optimisation of camber and toe
- Increased cornering stability
- Improved sense of connection to rear axle
Unlike the rubber‑bushed factory arms, our rose-jointed toe arms maintain consistent geometry during acceleration and high-speed cornering.
Suspension Packages Explained
If you wish to take GT4 RS handling to the next level, Suspension Secrets offers a range of complete suspension packages for road and track use.
Circuit Handling Pack Kinematics Kit
Designed to fix the Cayman GT4 RS's biggest handling weaknesses, the Circuit Handling Pack Kinematics Kit from Suspension Secrets significantly reduces understeer, enhances steering accuracy, cuts body roll, and improves overall chassis stability and control.
Includes:
- Top mounts with increased camber and caster
- Upgraded front and rear Eibach racing springs
- Spring cups
- Bump-steer tie rod ends
- Adjustable rear toe arms
- Camber shim kit
This package provides more camber adjustment, increases caster angle, stops the rear end skipping on corner exit, and reduces diving under braking.
Best for: Both amateur and more serious trackday drivers
Circuit Handling Pack - Stage 2 with ‘305’ rear top mounts
The Circuit Handling Pack Kinematics Kit - Stage 2 is a comprehensive track solution for those owners looking to extract maximum handling performance from their Cayman GT4 RS.
Includes:
- Top mounts with increased camber and caster
- Upgraded front and rear Eibach racing springs
- Spring cups
- Bump-steer tie rod ends
- Adjustable rear toe arms
- Camber shim kit
- Camber Rear Top Mounts - Stage 1 (allows 305-section rear tyre fitment)
- Front Lower Control Arm Inner Monoballs
- Rear Lower Control Arm Inner Monoballs
- Front Solid Control Arm Bushes
Best for: Trackday and racing enthusiasts
Circuit Handling Pack - Stage 2 with ‘325’ rear top mounts
The Circuit Handling Pack Kinematics Kit - Stage 2 with ‘325’ Stage 2 rear top mounts (pictured above) achieves the previously impossible.
With this exclusive package, you can fit 325-section rear tyres to your Cayman GT4 RS whilst retaining the OEM dampers, PASM and OEM bump/droop ratio of the rear dampers.
Full package includes:
- Top mounts with increased camber and caster
- Upgraded front and rear Eibach racing springs
- Spring cups
- Bump-steer tie rod ends
- Adjustable rear toe arms
- Camber shim kit
- Camber Rear Top Mounts - Stage 2 (allows 325-section rear tyre fitment)
- Front Lower Control Arm Inner Monoballs
- Rear Lower Control Arm Inner Monoballs
- Front Solid Control Arm Bushes
Best for: Hardcore track driving enthusiasts
Porsche Cayman GT4 RS Suspension FAQ
What handling problems do suspension upgrades fix on the Cayman GT4 RS?
Targeted suspension upgrades correct the GT4 RS’s key weaknesses, including front-end understeer, rear instability under power, excessive nose dive during braking, and uneven tyre wear. Addressing these issues delivers a more predictable, confidence-inspiring car on both road and track.
Which suspension upgrade should I install first on a GT4 RS?
Adjustable front camber plates are the best first upgrade. They unlock additional negative camber beyond the factory limit, immediately improving front-end grip, turn-in response, and steering feel while reducing tyre wear during hard driving.
Why are adjustable rear toe arms important on the GT4 RS?
As rear camber is increased for improved cornering grip, the factory toe arms run out of adjustment. Upgraded adjustable rear toe arms allow precise toe-in to be restored, improving traction, stability, and confidence on corner exit.
Will these suspension upgrades work with OEM dampers and PASM?
Yes. All Suspension Secrets suspension upgrades and handling packages are designed to work seamlessly with OEM dampers and PASM, allowing you to retain factory functionality while dramatically improving handling performance.
Do I need a professional alignment after installing suspension upgrades?
Absolutely. A professional suspension geometry alignment is essential to unlock the full benefits of upgraded components. Correct camber, toe, and caster settings maximise grip, braking stability, and tyre life, ensuring your investment delivers real performance gains.
Tested and developed by Suspension Secrets through extensive road and track evaluation, these upgrades unlock the full chassis potential of the Porsche Cayman GT4 RS. By correcting factory understeer, improving tyre wear, and enhancing braking stability, they transform the GT4 RS into the focused, confidence-inspiring driver’s car it was always meant to be.