Do I need slotted discs?
There is no straight forward answer to this, and it really depends on what you want from you brakes. Slots (or less commonly now days – drilled holes) can increase friction levels, and assist with the removal of hot gasses that cause brake fade. However, they can also increase the chances of brake squeal.
Other than high-end performance vehicles, most street brake discs are plain (no slots or drill holes) as it is not required to achieve required performance levels. However almost every competition vehicle will have slotted discs.
The slots perform a few roles:
- Help remove gas build up and debris or moisture between pad and disc.
- Lightly mill away any uneven pad build-up which helps keep the contact surface in better condition.
- In some cases they can change the friction levels.