I was at the track this weekend and looked at SG roadster... Willwoods up front and Metrics in the back...I talked to the guy and he says the thing stops great.. Uses a factory GM Mastercylinder an aluminum one. Has a portioning valve for biased and has residual valves in line.. The only thing that he has to do every day is gets in the car and pumps the brakes up. He said the petal is soft if it sits overnight or for a couple of days. he is not sure why.Said that when they first put the brake set up in they blead the brakes trying to get rid of the soft pedal after sitting and it would not clear up. Once he "cycles" the brakes the brakes have lots of pedal and work fine all day. He is going to see if they have a make and model on the master cylinder.