Porsche 991 GT3 Tuning Guide

The Porsche 911 991 GT3, produced between 2013 and 2019, is a high-performance sports car that already delivers incredible driving dynamics straight from the factory. Whether you own the 3.8 or 4.0 model, the 991 GT3 is a capable machine designed for track days and spirited driving. However, many owners choose to modify their vehicles to enhance performance further, improve aesthetics, or simply to personalise their cars.

This modification guide explores common and practical upgrades for the 991 GT3, taking into account the car’s existing capabilities and offering suggestions that maintain or improve its performance and driving experience.

Check out all of our listed parts for your 991 GT3 here!

Performance Modifications

Exhaust System Upgrade

One of the most popular modifications for the 991 GT3 is the exhaust system. The factory exhaust on the 991 GT3 is already tuned for performance, but many owners opt for an aftermarket exhaust to achieve a more aggressive exhaust note or improve sound at high RPMs.

• Sport Exhaust: A more performance-oriented exhaust, such as a valved system, allows for a deeper tone with the flexibility to quieten down when cruising or open up when on the track. This modification often leads to weight savings, as many aftermarket exhaust systems are lighter than the stock version.
• Cat-delete Pipes or High-Flow Catalytic Converters: For those who are looking for maximum sound and performance, replacing the catalytic converters or adding high-flow versions can improve exhaust flow, giving the engine a more responsive feel.

Check out Milltek Sport for 911 991 GT3 here

Brake Pads and Discs

Although the 991 GT3 comes equipped with excellent brakes, performance drivers who regularly track the car might want to upgrade their braking components for better fade resistance, cooling, and performance under stress.

• Upgraded Brake Pads: Aftermarket performance brake pads can offer superior stopping power and higher heat tolerance, especially on track days. Look for pads designed specifically for high-performance applications, which provide a better balance of performance and wear.
• Carbon Ceramic Brake Discs: While the GT3 is available with Porsche’s carbon-ceramic brake discs (PCCB), many owners opt to upgrade to aftermarket carbon ceramic discs or drilled/slotted steel discs for better cooling and performance, especially in motorsport situations.

Check out our range of aftermarket and performance braking items here

Suspension Upgrades

The suspension of the 991 GT3 is already finely tuned for excellent handling. However, for those who want to push the limits further on the track or improve driving dynamics on the road, suspension upgrades can be beneficial.

• Lowering Springs or Coilovers: For better handling and a more aggressive stance, owners may choose to lower the car. Coilovers offer adjustable ride height, allowing owners to tune their suspension for either track or street use.
• Performance Sway Bars: Upgrading sway bars can help reduce body roll during aggressive cornering and provide sharper handling characteristics.

Check out our listings for 991 GT3 Suspension parts here

Air Intake System

Improving the airflow to the engine is another way to unlock more performance. Aftermarket cold air intake systems or high-performance filters can increase air intake efficiency, potentially providing a modest power gain and a more noticeable intake sound.

• High-Flow Filters: Replacing the stock air filters with high-flow options can help optimise the air-to-fuel ratio, especially if other performance upgrades (like exhaust or ECU remapping) have been made. JXL Performance recommend the K&N Performance replacement air filters.

ECU Remapping

For those who want to extract more power from the naturally aspirated engines of the 991 GT3, a remap or tuning of the engine control unit (ECU) can offer improvements in throttle response, power output, and overall performance. This modification is best paired with upgrades such as a sports exhaust or cold air intake to ensure the car is properly tuned for the added performance.

Aesthetic Modifications

Wheels

Upgrading the wheels is a popular modification, not only for aesthetic reasons but also to reduce unsprung weight, which can improve handling and acceleration. Lightweight forged wheels are a great option and can help reduce overall vehicle weight while maintaining strength and durability.

Body Styling

For those looking to further enhance the aggressive look of the 991 GT3, several body styling options are available. These modifications can also improve aerodynamics, especially for those who take their GT3 to the track.

• Front Splitter and Rear Diffuser: These modifications improve aerodynamics by reducing lift and increasing downforce. Carbon fibre options are often lightweight and offer a race-inspired look.
• Side Skirts: Adding side skirts can further enhance the car’s stance, giving it a more track-ready appearance while improving airflow along the sides of the car.
• Rear Spoiler: The GT3 already comes with an active rear spoiler, but for those seeking additional downforce, aftermarket spoilers or a larger rear wing can be a popular choice. These are particularly useful for high-speed stability and track driving.

Conclusion

While the Porsche 911 991 GT3 is already a highly capable car straight from the factory, the desire to personalise or enhance its performance is natural for many owners. Whether you’re looking to improve sound, handling, or appearance, there are numerous options available to tailor your car to your specific needs and preferences.

It's essential to approach modifications with consideration for the car's existing performance and balance. Always ensure that the modifications you choose complement the GT3’s exceptional engineering and do not compromise its reliability or handling characteristics. With the right upgrades, you can elevate your driving experience to new heights while enjoying the iconic Porsche thrill.