Brake discs Bosch or OEM Volkswagen

The best and most economical upgrade is using the 9.4 inch vented rotors from the '83 & '84 GTI's. With new 9.4 inch vented rotors and the right performance pads, you will have much better braking capacity without having to swap master cylinders and proportional rear valves.

Stopping is sharp and sudden, with a seemingly discordant combo of 13-inch discs up front and 10-inch discs in the rear.

I'll put it to you this way, you will need brakes when you are done with the track session. I warped several sets of rotors on my old 2.0 Golf during track days.