The Build: What's Actually on This 718 Boxster
| Item | 718 Boxster (982) STOPFLEX Build |
|---|---|
| Vehicle | Porsche 718 Boxster (982), mid-engine roadster |
| Front setup | 991 GT3 6-piston caliper with 400mm STOPFLEX carbon ceramic rotor |
| Rear setup | 4-piston caliper with 380mm STOPFLEX carbon ceramic rotor |
| Pads | STOPFLEX low-dust ceramic compound |
| Weight saved | About 18 kg (40 lbs) total, as recorded on this build |
| Wheel fitment | Sized around 20-inch wheel clearance |
| Scope | Custom front and rear big brake conversion |
Read this before you order
This isn't a universal bolt-on. It's a custom GT3-style conversion, and the front six-piston calipers may need the correct uprights, knuckles, or application-specific adapters. The 400mm front rotor is built around 20-inch wheel clearance, so confirm your wheel size and current brake setup before buying.
What the Upgrade Changes, and What to Check
| STOPFLEX feature | Why it matters on a 718 Boxster | What you notice |
|---|---|---|
| 400mm front rotor + GT3 6-piston caliper | The factory four-piston package runs low on thermal headroom during repeated hard stops. A bigger, stiffer front end adds capacity right where the 718 loads it most. | Firmer, more repeatable pedal on a mountain descent or a track session, instead of fade creeping in lap after lap. |
| Carbon ceramic rotors, ~half the weight of steel | This is a light mid-engine car that lives and dies on response. Cutting rotating unsprung mass is one of the few brake changes you actually feel in the steering. | Cleaner turn-in and a suspension that settles quicker over broken pavement. About 18 kg gone off the corners. |
| Heat-stable friction | Carbon ceramic holds roughly 0.3μ surface friction even at 900°C in testing, so it doesn't go soft when the brakes get hot. | The tenth hard stop feels close to the first, which is the whole point on a back road or a hot lap. |
| Low-dust pad pairing | Street Porsches are notorious for caking wheels in black dust. STOPFLEX pads keep things clean and still run over 0.4μ at normal temps. | Wheels stay clean between washes, and the rotors don't rust-ring after a rainy week sitting outside. |
| Long-fiber CCB construction | Long-fiber carbon ceramic is stronger than chopped-fiber discs, which supports both heat stability and street durability. | Street life can reach roughly 250,000 to 300,000 km off-track, so you're not feeding it rotors like a steel setup. |
What gets better
- More thermal margin for repeated hard stops on road or track
- About 18 kg less unsprung and rotating mass
- Sharper turn-in and quicker suspension recovery
- Very low brake dust with STOPFLEX pads
- Rotors that don't rust after rain exposure
What to confirm first
- Your current front and rear brake configuration
- Wheel diameter and spoke clearance (this build assumes 20-inch)
- Correct uprights, knuckles, or adapters for the GT3 front calipers
- Whether the car is mostly street-driven or sees regular track time
- Pistons and master cylinder match for your exact hardware
If you're not sure your car lines up with the spec shown here, send us your details and we'll confirm Porsche 718 Boxster (982) fitment before you order through our Porsche CCB collection.
Build Gallery
718 Boxster Carbon Ceramic Brake Questions
Why run 911 GT3 front calipers on a 718 Boxster?
The GT3 six-piston front caliper is larger and more rigid than the factory 718 four-piston unit, so it clamps a bigger rotor with less flex. Paired with STOPFLEX carbon ceramic rotors, it builds a higher-capacity front end aimed at repeated hard braking rather than just looks.
Is this only worth doing for a track car?
No. Track and canyon driving show the biggest gains in heat tolerance, but a daily-driven 718 still benefits from lighter unsprung mass, very low dust with STOPFLEX pads, and rotors that do not rust after rain.
Will the 400mm front and 380mm rear rotors clear factory 20-inch wheels?
This build is sized around 20-inch wheel clearance. A 400mm front rotor with a six-piston caliper is usually tight or impossible behind 19-inch wheels, so confirm your exact wheel size and spoke design before ordering.
Do you have to swap the master cylinder for this conversion?
Generally no. This build runs the six-piston front calipers on the standard 718 master cylinder. Final confirmation should still be based on the exact hardware and pistons used in your conversion.
Is this a plug-and-play kit for any 718 Boxster?
No. This is a custom big brake conversion. The GT3 front calipers may need the correct uprights, knuckles, or application-specific adapters, so your exact car has to be checked before you order.
How long do STOPFLEX carbon ceramic rotors last on the street?
Used on the street and kept off the track, STOPFLEX carbon ceramic rotors can reach roughly 250,000 to 300,000 km, far longer than typical steel rotors. Real-world life depends on how the car is driven and set up.
