The GT4 RS is a seriously capable sports car, but that doesn’t mean its factory suspension setup can’t be dramatically improved. With the following Porsche Cayman GT4 RS suspension upgrades, you can stop the rear end skipping under throttle that the car is known for, as well as reduce mid-corner understeer and eliminate nose diving under braking.
In this GT4 RS suspension upgrade guide, we’ll cover the car’s handling flaws and reveal the most effective Porsche GT4 RS handling upgrades for the road and track. Read on to discover what your tuning options are for the flagship Cayman…
This Guide Is For Owners Who:
- Track their car regularly
- Experience understeer or rear instability
- Want improved tyre wear and lap times
- Demand sharper steering feel and feedback
Cayman GT4 RS Overview
Debuting in late 2021, the Porsche GT4 RS is based on the 718-series Cayman chassis but features many performance enhancements. The car’s naturally aspirated, flat-six powerplant is linked to a seven-speed PDK transmission, and is rated at 500hp with 450Nm of torque. These figures result in 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.
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 Nürburgring Nordschleife lap time of 7min 9.30secs, over 23 seconds faster than the GT4. However, this is only the beginning for Porsche’s GT4 RS…
Common Suspension & Handling Problems
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 they can be solved in the following ways…
How To Fix GT4 RS Handling Issues
- Increasing front camber to reduce understeer and 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
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.
Full benefits of a Cayman GT4 RS geometry setup include sharper steering response, increased cornering grip, improved rear traction, enhanced braking stability and more consistent tyre wear.
Best Suspension Upgrades
So, you’ve decided GT4 RS suspension upgrades are the way forward – but where to start? Front camber plates and rear toe arms form the foundation of all Suspension Secrets handling packages and represent a highly effective first step in the process of improving your GT4 RS’s handling performance. Here’s how they work…
Camber Caster Plates/Front 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.
We recommend fitting our top mounts instead of using camber shims because shims move the front wheels into a position that causes contact with the arch liners.
Why Choose GT4 RS Camber Plates
- 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 upgraded front top mounts that allow more negative camber to be dialled into the 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.
Why Fit Our GT4 RS Rear Toe Arms:
- 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 adjustable rear toe arms feature solid rose joints that maintain consistent geometry during acceleration and high-speed cornering. This increased predictability in the car’s responses ramps up driver confidence and encourages even faster driving on circuit.
Uprated Spring Package
Despite its billing as a precision trackday tool, the Porsche GT4 RS suffers pronounced diving under braking, as well as rear instability when driven hard on circuit. This is due to sub-optimal front and rear spring rates from the factory that do not allow the stock dampers to work efficiently.
In essence, the GT4 RS front springs are too soft and the rear springs are too stiff. Thankfully, this situation is easily fixed by our Uprated Spring Package developed in partnership with Eibach.
Once fitted with this suspension upgrade, the 500hp Cayman is a far more stable and predictable machine. As an added bonus, this GT4 RS spring package allows the ride height to be lowered 20mm for extra handling prowess, or maintain the stock road stance.
GT4 RS Suspension Packages
If you’re looking for comprehensive GT4 RS handling packages, Suspension Secrets offers a range of complete solutions for road and track use. Backed by a lifetime warranty, these kits combine the parts mentioned above and more upgrades to further enhance handling performance.
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.
This kit includes in-house developed rear top mounts for the GT4 RS, which allow the fitment of 305-section rear tyres. This setup contributes to enhanced cornering grip, traction and braking performance.
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
Unlocking The Full Potential
Using the Porsche Cayman GT4 RS suspension upgrades detailed above, the car is elevated to a new level of greatness. Already a hugely capable weapon on circuit, with fine-tuning of its chassis hardware the full potential of the GT4 RS is unleashed.
Porsche Cayman GT4 RS Suspension FAQs
The rear of my GT4 RS is skipping on corner exit – what should I do?
Rear instability under throttle is usually caused by an oversprung rear setup combined with limited toe adjustment. Reducing rear spring rate, increasing front spring rate for better balance, and fitting adjustable rear toe arms to restore proper toe-in will dramatically improve traction and predictability on corner exit.
How do I reduce the amount of front diving under braking on my GT4 RS?
Excessive nose dive is typically improved by correcting suspension geometry, increasing front spring support, and optimising camber and caster settings. Upgraded springs combined with a professional alignment significantly enhance braking stability and control.
What suspension upgrade makes the biggest difference to GT4 RS handling?
Adjustable front camber caster plate top mounts provide the most immediate improvement. They unlock additional negative camber and caster, increasing front-end grip, sharpening steering response, and reducing understeer during aggressive driving.
Do GT4 RS suspension upgrades work with OEM dampers and PASM?
Yes. Quality suspension upgrades such as camber plates, adjustable toe arms, and handling packages are designed to integrate seamlessly with factory dampers and PASM, retaining OEM functionality while delivering major performance gains.
See our full range of Porsche Cayman GT4 RS suspension upgrades here.
