Table of contents
The Porsche Cayman GT4 is a dream car for driving purists but has significant untapped potential in its chassis. Suspension upgrades can reduce the understeer present in the factory setup while improving tyre wear and enhancing braking stability on the road and track.
In this GT4 suspension tuning guide, we reveal common handling complaints, the most effective suspension upgrades, and how Suspension Secrets parts unlock the full potential of Porsche’s 981 and 718 GT4.
Cayman GT4 Suspension & Handling Overview
The 981-series Porsche Cayman GT4 launched in March 2015. Featuring a mid-engined layout, its 3.8-litre, flat-six engine produced 385hp and 420Nm of torque. This ‘9A1’ powerplant could be teamed with a six-speed manual or seven-speed PDK dual-clutch gearbox.
Suspension comprised a plethora of 911 GT3 components, stiffened springs, plus adjustable anti-roll bars front and rear, and Porsche’s Active Suspension Management (PASM) electronically controlled damping.
In spring 2020, the updated 718-series Cayman GT4 went on sale. The revised four-litre six-cylinder boasted an increased output of 420hp and 420Nm (with the manual gearbox; 430Nm with PDK), and there were aerodynamic improvements too.
However, in terms of suspension both versions of the Cayman GT4 are set up to provide safe handling that suits the broadest range of driving abilities. This creates the following issues…
Common Porsche Cayman GT4 Handling Problems
- Mid-corner understeer
- Limited front axle grip
- Excessive front tyre wear during high speed driving
- Limited steering communication
These frustrating characteristics hold back the GT4 package and also rob the car of time on circuit.
Thankfully, all these issues can be fixed with bolt-on suspension upgrades.
Common Handling Problems (And How to Fix Them)
The Porsche Cayman GT4 is set up to understeer at the limit, affecting driver enjoyment and confidence in the car. It’ll also cost you a small fortune in front tyres.
The most effective fixes are:
1. Increasing front camber to reduce understeer
2. Improving rear toe control to enhance traction
3. Lowering the centre of gravity to reduce pitch and roll
4. Correcting geometry with a professional alignment
All combined, these upgrades transform how the GT4 communicates, corners and brakes on the road and track.
Porsche Cayman GT4 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 Geometry Setup
- Sharper steering response
- Increased cornering grip
- Improved rear traction
- Enhanced braking stability
A professional alignment is the single most cost-effective handling upgrade you can make.
Essential Suspension Upgrades for Porsche Cayman GT4
This section covers the essential suspension upgrades for the Porsche Cayman GT4. In other words, the parts that deliver the greatest handling improvements with minimal compromise. These upgrades form the basis of all Suspension Secrets handling packages and are the ideal starting point for both road and track-focused builds.
Camber Caster Plate Top Mounts
A lack of factory camber adjustment is the primary cause of the Cayman GT4’s mid-corner understeer.
Adjustable camber plates allow additional negative camber to be dialled in, significantly improving front-end grip and steering feel.
Why Camber Plates Matter on the Cayman GT4
- Reduce understeer
- Sharpen turn-in
- Increase steering feedback
- Improve tyre wear on track
Suspension Secrets Adjustable Camber & Caster Plates also increase caster angle, providing dynamic camber gain as steering lock is applied. These camber plates are fully compatible with OEM dampers and PASM.
Adjustable Rear Toe Arms
With understeer reduced by the upgraded front top mounts mentioned above, which allow more negative camber to be dialled into the GT4’s chassis, it’s important to increase the amount of adjustability on the GT4’s rear axle to further improve cornering grip and chassis response.
Although the factory toe arms can be adjusted, their range is limited and compromises overall setup, especially as more negative camber is applied. As rear camber is increased to improve cornering grip, it becomes impossible to achieve the toe-in necessary for 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
- Solid mounting to eliminate flex under load
- Increased cornering stability
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 the GT4’s 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’s biggest handling weaknesses, the Circuit Handling Pack Kinematics Kit maximises grip, ensures the full contact patch of the tyre is utilised during hard driving, and substantially improves chassis balance.
- Top mounts with increased camber and caster
- Upgraded front and rear Eibach racing springs with front helper springs
- Spring cups
- Bump-steer tie rod ends
- Adjustable rear toe arms
- Camber shim kit
This package provides more camber adjustment, increases caster angle, improves rear end stability, and reduces body roll without affecting ride quality. OEM ride height can also be maintained, or a lower ride height if you wish.
Best for: Fast road and track use
Circuit Handling Pack - Stage 2 (305 Rear Tyres)
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.
Includes:
- Top mounts with increased camber and caster
- Upgraded front and rear Eibach racing springs with front helper 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 (325 Rear Tyres)
The Circuit Handling Pack Kinematics Kit - Stage 2 with ‘325’ Stage 2 rear top mounts achieves the previously impossible.
With this exclusive package, you can fit 325-section rear tyres to your Cayman GT4 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 with front helper 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 Suspension FAQ
What is the best suspension upgrade for the Cayman GT4?
Camber plates provide the biggest improvement by reducing understeer and front tyre wear.
Does the Cayman GT4 need alignment after suspension upgrades?
Yes. Alignment is essential to unlock the benefits of added camber and toe adjustment.
Are suspension upgrades worth it on a GT4?
Yes. The factory setup prioritises safety, while aftermarket upgrades unlock the chassis’ full potential.
Tested and developed by Suspension Secrets through extensive road and track evaluation, these upgrades unlock the full chassis potential of the Porsche Cayman GT4. By correcting factory understeer, improving tyre wear, and enhancing braking stability, they transform the GT4 into the focused, confidence-inspiring driver’s car it was always meant to be.