Traditionally, the 928 owner's brake upgrade choices were limited to upgrading to the brakes found in the next-newer generation of 928's. 928 and 928 S owners upgraded to brakes for a 928 S4 or GT, and S4/GT owners went up to GTS brakes. And there it stopped.
But wheel upgrades haven't stopped as 18" and 19" wheels are now fairly common, and the brakes have not kept up. And if you're a racer - you may have found like many of us that you can over-cook the GTS brakes. But no more.
928 Motorsports in collaboration with Brembo has developed a new brake kit for the 928, dubbed the "GT1" big brake kit.
Not to be confused with others' "big brake" kits sporting 304 or 322mm rotors, these GT1 brakes are a whopping 355mm rotor with a lightweight two-piece rotor and hat combination.
|MODEL||ROTOR DIAMETER||EFFECTIVE RADIUS||ROTOR WEIGHT|
80-85 US models
|282 mm||108 mm||12.28 lb|
|80-86 Euro S models||282 mm||110 mm||15.41 lb|
|87-91 S4 and GT||304 mm||121 mm||18.10 lb|
|92-95 GTS||322 mm||131 mm||21.00 lb|
|993 TT||322 mm||131 mm||20.49 lb|
|928MS GT1||355 mm||150 mm||17.75 lb|
A WORD ABOUT 4-PISTON vs. 6-PISTON CALIPERS
We selected 4-piston calipers for our GT1 kit, and this is why:
There is a common misconception that 6-piston calipers have better stopping power than 4-piston calipers. That isn't true. The increase in stopping power comes from the increase in rotor diameter, effective radius, and the hydraulic gain of the system. Brake pad size and the number of pistons in the caliper have nothing to do with braking effectiveness.
Most 6-piston calipers flex more, cost more, and fit inside fewer wheels - making wheel fitment a challenge. Brake pads for a 6-piston caliper also cost more, and are offered in only a few materials. The only merit they have is that the brake pad on a 6-piston caliper is larger, so they last longer between pad changes - which is a valuable feature if you are endurance racing. But, it also means they cost more at each pad change.
On the other hand, our Brembo 4-piston caliper is stiffer, and requires 10mm less of clearance than the 6-piston model, so it will fit inside virtually all 18" wheels. It has a broad selection of brake pads available for it, and they cost less. Additionally, the 4-piston caliper features the quick release pad design, which is a nice feature for customers tracking their cars.
This kit fits all S4, GT and GTS models. A direct bolt-on fit. This kit also can fit 1978-86 models with a custom steel caliper adapter we manufacture and a set of early spindles.
DESIGNED WITH YOUR MASTER CYLINDER IN MIND
We specifically designed this kit to perform with the stock 928 master cylinder and brake bias valve, so that pedal force and pedal travel would be the same as stock. (I can hear you saying "how can you do that?" It's done by changing the diameter of the pistons in the calipers so that the mean hydraulic gain remains the same) This also means you can install our kit on the driveway - it took me less than 30 minutes per wheel - and you're done. No need to change the master cylinder or brake bias valve at all.
Although we designed this kit to be compatible with most all 18" and 19" wheels, a paper cut-out of the rotor and caliper is available for download and should always be used before ordering to confirm that your wheels will fit around these brakes. Brembo recommends a minimum of 3mm clearance between the caliper and the wheel spoke or rim.
928 MOTORSPORTS QUALITY
Brembo uses the highest quality components for everything from brackets to rotors to even the disc assembly hardware. Our parts last longer and these kits do not have the same issues commonly associated with brake kits from other manufacturers. Some brake companies advise to take off their product in the winter, rebuild calipers yearly, safety wire hardware in place, etc.
The resources Brembo has and the testing we do before a kit is released allows us to provide upgrades that do not require our customers to invest additional time babysitting the product.
COMPLETE KIT INCLUDES
|Ferodo FM 1000 (Front & Rear)|
|Ferodo FM 1000 w/ pad sensor (Front & Rear)|
|Ferodo DS3000 (Front Only)|
|Hawk DTC 30 (Front & Rear)|
|Hawk DTC 60 (Front Only)|
|Hawk DTC 70 (Front Only)|
|Pagid Blue 4-2 (HP Street) (Front & Rear)|
|Pagid Orange 4-4 (Race) (Front & Rear)|
|Raybestos ST04 (Street) (Front & Rear)|
|Raybestos ST42 (Race) (Front Only)|
|Porterfield R4S (Street) (Font & Rear)|
|Porterfield R4 (Race) (Front & Rear)|
THIS IS A SPECIAL ORDER ITEM: All GT1 brake kits are custom built to order, so it is important to verify wheel fitment before placing the order.
SHIPPED IN MATCHED BOXES: Each GT1 kits ships in 2 boxes labeled Left / Right). This makes the installation even easier because customers do not have to determine the correct calipers or rotors for each side.
|Item||Caliper Color||Rotor Type||Brake Pads||Price (USD)||Shipping*||Availability|
* Domestic US shipping shown. International shipping will be calculated based on location.