Clarify T4 Brake Rotor Allowance
#39503 from David Mead · Rule change · TB 26-01 (2026-01 Fastrack)
In GCR, Section 9.1.9.2.D.6.a.6., change as follows:
"In T2-Performance alternative rotors, including 2 piece rotors are permitted. Rotors must be within 5% of OE diameter or a
maximum diameter of 360mm.
In T3- Performance alternative rotors, including 2 piece rotors are permitted with a maximum diameter of 360mm.
T4- Performance alternative 1-piece rotors are permitted but rotors must meet the sizes listed in the spec line. Spec lines
showing alternate brake kits are also permitted to use 1-piece performance alternative rotors of the same size."