Brake upgrades for the GT-R are certainly not common! Most owners seem happy to increase the power and leave the brakes standard. The stock brakes are ok with stock power, but are definitely not suitable for a 300+ BHP car!
There are upgraded disks and pads available for the standard set up, but in my experience these don't offer any increased stopping power or fade resistance. After my first track days destroyed a set of disks and pads within a few laps, I knew I had to find a better option!
I spent a lot of time looking into brake upgrades, however all the ones I could find seemed very expensive and were only suitable for cars with 17 inch wheels. A few owners have fitted AP 6pot callipers and 330mm disks, which give fantastic stopping power, but needs 17 inch wheels and costs well over £1000. Tarox also make a kit for the GT-R, but again, it's expensive and untested.
As a result, I decided to look into my own brake upgrade, and try to find something cost effective and easily available. After looking at the brakes on many other cars, and trying loads of different disk and calliper options, I finally made up my own solution, using mostly Mitsubishi GTO parts.
The GTO callipers are made by Sumitomo, and are very similar to FD RX7 calipers, aside from they use a thicker disk (296 x 30mm) from the factory. I found that the original bolt holes in the caliper lined up perfectly with the GTR hub bolt holes BUT! The caliper would sit very far out from the hub centre and also a long way towards the wheel face...
Here's the GTO caliper.
|
|
|
|
The piston bores seemed the ideal size for the conversion, however the challenge was to make this set up fit inside 15 inch wheels... I also wanted to use the larger GTO disks for better fade resistance.
 |
|
 |
 |
The next problem to solve was the disk needed offsetting further towards the wheel. To do this, I used some old wheel spacers, and had the diameter machined down to fit inside the disk. These were then mounted behind the disk, and longer wheel studs were fitted in the hub, to allow enough thread engagement to safely hold the wheel on.
 |
 |
 |
The disks and calipers could now be bolted to the hub using high tensile steel nuts and bolts.
 |
 |
 |
 |
 |
As a further experiment, I had a set of disks from a Mitsubishi Evo VI, which are 320 x32mm. These also have the same PCD and offset as the GTO disk, and after testing it on the car, I found these would also work with the GTO calipers, however 17inch wheels would be needed.
 |
 |
 |
 |
 |
So a good budget upgrade for GTR brakes is possible! However, I decided I needed something even better for serious track work with over 350BHP, so the next stage is to fit these Alcon calipers...
 |
 |
 |