I'm planning on writing to request a rule change allowing IT cars to keep ABS sytems intact.

Having used it all year on the SSC Golf, I've only had reinforced my belief that it is indeed true that anti-lock systems do not shorten braking distances, compared to a skilled foot.

Call this an inherent disadvantage of ABS over a correctly - if manually - balanced system. In addition VW's programming goes into what is called "ice mode" if it senses a prolonged lock-up, at which point the scale shifts down to something like 20% of the nominal brakin force. THAT'S fun, I can tell you...

ABS brakes DO however, (a) make it possible to put your right side tires in the wet grass under braking when a Spec Miata moves over on you without looking, ( keep you from flatspotting expensive tires due to driver error, and © modulate heel-toe downshifts with crappy pedal placement. Call these advantages in the real world.

Given the option, I'd prefer a correct non-ABS system with proper proportioning valves but that is a real engineering job. Simply disconnecting the sensors to meet the rule is rumored to leave the Golf with a really awful balance, although I won't know until August what really happens and I don't have any information on which to base statements about IT cars in general.

At the end of the day, the most valuable aspect of a rule allowing drivers to keep ABS might be a practical one: One less thing to have to screw up during a beginner's IT build.

I'm tempted to write my proposed rule change such that it deletes the rule requiring ABS to be removed; and amends the existing language about proportioning valves to (a) allow ABS removal/disabling, and ( allow prop valves ONLY if on cars without functional ABS - whether it has been removed or was never there in the first place.

This is an example of the kind of challenge that we are going to be facing as more cars come with what used to be considered exotic and forbidden technology. ABS has found its way onto the cheapest of hatchcraps so maybe it's time for a rethink.

Opinions?

K