I’m probably several months away from doing this, but I started looking into how to swap my clutch. I came across this page (http://www.e30zone.net/e30zonewiki/index.php/M20#Flywheel) that has this line:
“Two weights of flywheel were fitted to M20 engines. The standard flywheel is 8.4kg, while cars fitted with air conditioning have a flywheel 1.3kg lighter.”
The rulebook states (Section 18.104.22.168):
“After balancing, the flywheel must be within factory dimensions for diameter, and weigh at least 17.5 pounds.”
17.5 pounds is 7.95kg. The e30 zone site says that the AC-fitted flywheels weigh 7.1kg.
e30 zone is a UK site – did this difference not exist in US models? Or is there a disconnect with the rules? Or are there multiple ways to weigh a flywheel?