2023 Porsche 911 GT3 RS (992) Suspension Overview

The latest 992-generation Porsche 911 GT3 RS is probably one of the most hyped performance cars of recent years.

Since the car’s reveal almost a year ago, there has been a lot of rumour regarding 992 GT3 RS’ exact specification. The car’s heavy focus on generating tremendous downforce is the most obvious visual difference between the 992 GT3 and the 992 GT3 RS, but the changes to suspension system are just as important.

We recently had one of the UK’s first delivered 992 GT3 RS here with us at Suspension Secrets. This was the perfect opportunity to really take a deep dive, and to see just what was different between the latest GT3 and GT3 RS.

There’s a lot to take in here, so we’ve divided the car into a few sections, hopefully making it easier to navigate and to understand the changes Porsche Motorsport have made to create this very special car.

Let’s take a look!

Suspension – Front

The single biggest difference to the front suspension on the GT3 RS is that the suspension wishbones and tie rod ends have all been reprofiled to generate more front axle downforce. The reprofiled suspension components help to create 40kg of downforce at the suspension, greatly improving front axle grip. Whilst this design is commonplace for single-seater racing cars, such as in Formula One, this technique being used on a road car is very radical and, for us suspension geeks, is very impressive.

The GT3 RS features a 29mm wider track width, which is achieved with additional shims in the lower control arms. This increased track width, combined with wider front wheels fitted with 275mm tyres (versus 255mm on the 992 GT3) also help to improve front axle stability and grip. Track width is measured from the middle of the wheels on an axle, so whilst 29mm is the figure quoted by Porsche, the wider wheels and tyres mean that the track is significantly wider if measured from the outside edge to the outside edge of the front wheels.

Another significant change to the front suspension system is the increased diameter of the front anti-roll bar. The front anti-roll bar (which is made of carbon fibre on the Weissach Package equipped 992 GT3 RSs) is much thicker than the standard steel bar that is found on the 992 GT3. This increased thickness helps the GT3 RS to remain flat and stable when cornering at speed. This is especially important as the car’s increased downforce will enable much higher cornering speeds, making high-speed stability essential.

Another benefit of thicker anti-roll bars is that the spring rate does not need to be as high, as the anti-roll bar is managing the lateral roll of the car instead. As a result, the spring rates on the 992 GT3 RS are only 50% stiffer than the spring rates on the 992 GT3. Compare this to the Porsche Cayman GT4 RS which does not have thicker anti-roll bars compared to the standard Cayman GT4, instead the GT4 RS’ spring rates are 100% stiffer than the standard Cayman GT4’s which reduces ride refinement and comfort.

The overall design and pickup points of the 992 GT3 RS’ suspension is exactly the same as the 992 GT3. All the suspension bushes are solidly mounted, and the camber blocks that are used for adjusting the front camber angle are exactly the same as those found on the 992 GT3. The front camber angle on the GT3 RS is more aggressive than that found on the 992 GT3, however, resulting in reduced understeer and increased front axle grip.

Suspension – Rear

The rear suspension on the 992 GT3 RS is, on the whole, very similar to the rear suspension on the 992 GT3. The key difference is that all rear suspension bushes, which are rubber on the 992 GT3, are solidly mounted on the GT3 RS. This change to solid bushes eliminates any flex that would occur in rubber bushes. This removal of flex ensures the GT3 RS remains stable when cornering and improves the sense of connection the driver feels with the rear axle.

Similarly to the front axle, the rear axle track width has been increased on the 992 GT3 RS versus the 992 GT3. The increase in track width is 30mm thanks to the wider rear wheels and tyres (13” wheel with 335mm rear tyres) which enable the GT3 RS to make the most of its greatly increased downforce.

The rear axle steering system on the 992 GT3 RS is slightly more aggressive compared to that of the 992 GT3, which allows the 992 GT3 RS to be more manoeuvrable in low-speed corners as the rear steer module steers in the opposite direction to the front tyres, effectively shortening the wheelbase, and more stable in high-speed corners where the rear steer module steers in the same direction as the front tyres, extending the length of the wheelbase and increasing stability.

Another factor increasing stability when cornering is, again, a much thicker rear anti-roll bar compared to the rear anti-roll bar fitted to the standard 992 GT3. This anti-roll bar is made from carbon fibre (on Weissach Package equipped cars) and will help keep the GT3 RS level and stable when cornering at high speeds. The rear spring rate is also increased by 50% to better cope with the increased load that is exerted on the suspension due to the increase in rear downforce.

In-Car Adjustability

Whilst the Porsche GT cars have always had adjustable chassis and suspension components, the 992 GT3 RS introduces a whole host of adjustable chassis features and driver aids that can be configured and adjusted using steering wheel mounted rotary dials.

The most prevalent of these systems are the electronically-adjustable damper settings. From their seat, a driver can adjust the bump and rebound characteristics of their 992 GT3 RS’ suspension, with front to rear settings also being independently adjustable. This allows you to tailor how the GT3 RS drives to a specific circuit or road, or to suit a certain driving style.

On the 992 GT3 RS, both the power and coast characteristics of the rear electronic differential can be adjusted from inside the car. This is quite unusual for a car to allow the driver to tweak the characteristics of the differential themselves. Some performance cars using e-diffs may change their characteristics depending on a selected driver mode, but this is rarely configurable. GT3 RS drivers will be able to influence how their Porsche enters and exits corners thanks to this adjustability, again allowing them to tailor the car’s behaviour to suit their driving style.

The final aspects of chassis adjustment from within the 992 GT3 RS’ cabin are the traction control and electronic stability systems. Both systems feature multi-stage adjustability; a helpful system for drivers who are building their skills and confidence on track, as it allows them to gradually reduce electronic intervention, as opposed to the more conventional “on” or “off” systems.

Aerodynamics – Overview

Visually, the 992 GT3 RS cuts an imposing figure. It’s a vast machine in every sense of the word; it’s long, wide, and low and the sculpted body doors and front and rear wheel arch cutaways give the lower portion of the car a real sense of taughtness, as if the body panels are instead a skin that is barely stretched across the car.

The 992 GT3 RS is covered in aerodynamic aids and surfaces, so much so, that it can be quite overwhelming. We’ll explore the outright potency of the aerodynamic aids before dissecting the aerodynamics across the front and rear of the car.

The headline figure is this: the 992 GT3 RS generates 860kg of downforce at 175 mph. That is the equivalent of having a Kia Picanto strapped to the roof!

What is more impressive is that at 124 mph, the 992 GT3 RS makes the same amount of downforce (409kg) as the previous 991-generation GT3 RS made at its top speed of 194 mph. 

On previous 911 GT3s and GT3 RSs the aerodynamics have been manually adjustable, but the 992 GT3 RS is the first to use active aerodynamics. Both the diffuser inside the front bumper and the enormous rear wing are electronically controlled. At any given time, the GT3 RS determines how much downforce it needs or can handle, and adjusts both the front venturi ducts and rear wing accordingly.

The 992 GT3 RS also features a passive anti-dive system, which prevents the car from becoming destabilised as the downforce bleeds off during heavy braking. This allows drivers to drive with complete confidence, knowing that at any given time, their GT3 RS will be working to give them the most aerodynamic grip possible.

Aerodynamics – Front

Front downforce has always been something Porsche’s engineers have been chasing for a long time on the Porsche 911. With most of the car’s weight over the rear axle and the massive rear wing, the front is always going to be the area that struggles with front downforce. Regulations prevent Porsche from being able to use the tried and tested method of sticking a large front splitter and canards on the GT3 RS, so Porsche have had to be more creative in their search for increased front downforce.

As previously mentioned, the front aerodynamics on the 992 GT3 RS are active. This is all possible thanks to Porsche’s decision to move the GT3 RS’ radiator into the front storage compartment. Previous GT3s and GT3 RSs have had three front radiators: one centrally located, and then one radiator ahead of each of the front wheels.

By using a single radiator unit in the nose of the car, all the space behind the front bumper has been freed up and redesigned to generate downforce. Inside the front bumper is a diffuser that features electromechanically-operated aerodynamic flaps that control the airflow into the wheel arches, improving front downforce.

These flaps on the leading edge of the inner wheel arch work in conjunction with the rear wing to maintain aerodynamic balance. The 992 GT3 RS also features more extreme wheel arch cutouts on the trailing edge of the front wheel arches. This feature was first seen on the Cayman GT4 RS, but the GT3 RS takes them to the next level. The cutout on the trailing edge is far more extreme compared to the cutouts on the GT4 RS. The GT3 RS also features vortex generators that help to channel the air that is leaving the wheel arches cleanly down the side of the car without causing instability. This is all helped by the GT3 RS all-new carbon fibre doors, which have allowed Porsche to mould them more drastically to enhance the vortex generators’ benefits.

Aerodynamics – Rear

The rear half of the GT3 RS has also received a significant redesign in order to improve aerodynamic efficiency and manipulation. One of the most noticeable changes (apart from the massive rear wing) is the inclusion of roof-mounted fins that run along the spine of the car. These fins channel the hot air escaping from the nose-mounted radiator away from the engine intakes in order to ensure the engine is only fed with cool air for optimum performance.

The rear wing on the 992 GT3 RS is larger than any wing previously fitted to a 911 GT3 RS. In terms of both width, height and depth, the wing is gargantuan. As previously mentioned, the rear wing on the 992 GT3 RS is fully active, using electro-pneumatic actuators to control the wing’s movement. The wing will constantly adjust its angle of attack in order to generate the most amount of downforce in any given situation.

The wing also features both DRS (drag-reduction system – for improved top speed on straights) and the ability to work as an airbrake during heavy braking. Porsche claims that when stopping from 124 mph, the airbrake helps to reduce stopping distances by 2.5 metres, with the effectiveness of the airbrake increasing as speeds rise.

Conclusion

And there we have it. A quick look at the breadth and depth of the changes Porsche have made to make the 992 GT3 RS an absolute monster on the racetrack. We’ve never seen such in-depth chassis and aero changes from a GT3 to a GT3 RS and we look forward to seeing these cars being used out on track.

If you want one single fact to take away from the 992 GT3 RS, then it should be this one: in high-speed corners, the 992 GT3 RS on Pirelli P-Zero Trofeo RS tyres corners faster than a full-blown 992 Cup Car on slicks. 

That’s a job well done, we’d say.