The Porsche 718 Boxster is the purest expression of mid-engine balance. However, for owners who chase lap times, the standard 4-piston brakes are the limiting factor. They lack the thermal capacity and pad volume of the GT models, leading to fade and rapid wear on track. This case study details the ultimate "OEM+" solution: a Custom GT3 Brake Conversion featuring 911 GT3 6-piston calipers and StopFlex Carbon-Ceramic rotors.
The Struggle
While brilliant on the street, the standard 718 brakes face challenges on the circuit:
- Thermal Saturation: The smaller 330mm iron rotors heat soak quickly during extended sessions, leading to a soft pedal.
- Pad Taper: The smaller 4-piston calipers can suffer from pad taper under extreme heat, reducing braking efficiency and increasing running costs.
- Brake Dust: Factory pads generate excessive dust, ruining the look of the wheels.
Technical Specification
This is a complete Custom Big Brake Kit (BBK) overhaul. It retrofits the massive 6-piston front calipers from the 991 GT3 and pairs them with lightweight StopFlex Carbon-Ceramic rotors, fitting perfectly within 20-inch wheels.
| Vehicle | Porsche 718 Boxster (982) |
|---|---|
| Front Hardware | OEM GT3 6-Piston Caliper + 400mm CCB |
| Rear Hardware | OEM 4-Piston Caliper + 380mm CCB |
| Weight Saving | ≈ 18 kg (40 lbs) Total Reduction |
| Pad Material | StopFlex Low-Dust Ceramic Compound |
Compatibility Redline
This is a Custom Big Brake Kit (BBK) application. It requires upgrading the front uprights/knuckles or using specific adapters to mount the 991 GT3 6-piston calipers. The StopFlex 400mm rotors are engineered to pair specifically with this caliper setup. This is also a direct replacement for standard 718 4-piston calipers.
Engineering Validation
1. GT3 Stopping Power
Upgrading to the 6-piston GT3 caliper increases pad surface area by nearly 50%. Combined with the 400mm (15.7 in) StopFlex rotor, thermal capacity is effectively doubled. This setup eliminates fade entirely, allowing you to brake deeper and harder, lap after lap, mimicking the performance of a 718 Spyder.
2. Mid-Engine Agility Amplified
StopFlex carbon-ceramic discs are over 45% lighter than factory iron discs. Removing ~18 kg of rotating unsprung mass sharpens the steering response and allows the suspension to react faster to mid-corner bumps. The car feels even more telepathic, enhancing the 718's celebrated balance.
3. Clean, Silent Operation
Our ceramic pads are formulated for virtually no dust, keeping your wheels pristine. The corrosion-proof rotors eliminate the unsightly rust ring common on iron discs, ensuring the car always looks showroom-ready.
4. OEM+ Aesthetics
This upgrade looks like it came from the factory. The massive yellow GT3 calipers fill the 20-inch wheels perfectly, giving the car a "baby Spyder" appearance. The carbon-ceramic rotors add a high-tech, exotic flair that distinguishes the car from a standard 718.
Installation Gallery
In-Depth 718 Bespoke FAQ
Q: Why use 911 GT3 calipers on a 718?
This is the ultimate "OEM+" upgrade. The GT3 calipers are genuine Porsche motorsport hardware, offering a massive increase in rigidity and pad size over the 718's factory 4-piston brakes. When paired with our rotors, it's a bolt-on solution for achieving GT-level performance.
Q: Is this system overkill for a car that I mostly drive on the street?
While this system is 100% track-ready, the daily benefits are just as significant. The massive reduction in unsprung weight makes the car feel more nimble and improves ride quality. Plus, our virtually no-dust pads solve the biggest complaint of any Porsche owner: constantly cleaning brake dust off the wheels.
Q: Will this fit under my factory 20-inch wheels?
Yes. This 400mm/380mm setup is designed to clear standard Porsche 20-inch wheels (Carrera S, Turbo, etc.). However, 19-inch wheels will likely not clear the 400mm front rotor and 6-piston caliper.
Q: Do I need to change the master cylinder?
Generally, no. The 718 master cylinder moves enough fluid to operate the 6-piston front calipers effectively. The pedal feel remains firm and linear, similar to a GT4.
Q: What is the lifespan of these rotors?
For a 718 that sees mixed street and track use, StopFlex long-fiber rotors are incredibly durable. They resist the oxidation that kills carbon-ceramic rotors on older Porsches (Gen 1/2 PCCB). You can expect over 200,000 km of life on the street.
