SpeedSF Time Attack Series · 2026
Bimmer Challenge Northern California
BMW-focused time attack for NorCal drivers, run independently by SpeedSF on the same ruleset as the SoCal Bimmer Challenge hosted by Speed Ventures. Toyota GR Supra (A90/A91) is eligible. A NorCal vs. SoCal co-op event is in the works.
Classing
Car + modifications = class
Each car has a base value and every modification adds points. Your total decides your class. Submit before each event so we can confirm it.
B1over 16
B210.1 – 16
B36.1 – 10
B42.1 – 6
B52 or less
Racing slicks or tires under 40 treadwear move you to B2 at minimum.
Class calculator
Build your spec sheet
02
Vehicle
Base value: —
03
Modifications
Select everything on the car. Leave a section empty if it's stock.