so it's not the stock ABS that's limiting my deceleration it just crappy tires and less than optimal suspension etc.. thanks! I was hoping that was the case.
Actually, it's both. The stock ABS module DOES have a "maximum deceleration rate" limiter in it, which is governed by the ABS control module, but that could easily be overridden by (as you put it) crappy tires and less than optimal suspension. In essence, the module will not allow braking decel past a given rate, but the tractive capacity of the tires (crappy) and the control (or lack thereof) over the contact patch by the suspension do play a large part.
It seems like the best thing to do in brake zones is to calibrate your foot to stomp on the brakes to the point just before ABS activates and keep it there. Is that what you guys are doing?
Not only no, but HELL NO!! The closer you get to the limit in ANYTHING regarding road racing, the smoother and less aggressive you need to be. STOMPING on the brake pedal will give you the absolute maximum brake-application rate, however your stopping distance will actually be longer. When you "suddenly" apply brakes (panic stop or slam on the pedal), the load transfer forward will be violent, and will most likely overwhelm the suspension's ability to control that transfer. Think in terms of inertia. Hit the whoa pedal, and the ass-end tries to climb into the sky. Do it slowly, and the rear climbs slowly. Do it rapidly, and the rear climbs rapidly. Necessarily, when the back end is up in the air, there's very little load on the rear tires, and it won't take much to overwhelm the tractive capacity with the brakes. When you finally hit the point of maximum
possible braking force, and the rear end is climbing slowly, life is pretty good. You can balance the brake bias at that point with pad selection, rotor diameter, etc to get the back and the front on the edge of lockup TOGETHER. IF the ass-end, however, has been snapped into the air, the inertia of all that mass moving will cause an overshoot, unloading the rear tires even further. Reduced tractive capacity, and thus reduced braking effectiveness.
How to brake? "Touch-press," as explained
HERE. That's a sticky on track driving techniques on page 1 of this sub-forum... Short answer: you want roughly a 1/4-second (250mS) ramp rate between the first touch of the brake pedal, and having your foot all the way in. Keep that ramp rate linear, and will have control over the load transfer rate, and can feed it in as quickly as the suspension will take it. That control lets you get more effective braking through the entire braking event, rather than a sharper spike at the initial application, followed by a series of reduced dips in the braking trace until the suspension finally settles.
As you get closer to the limits, you really need to take the whole "slow down to go faster" mantra to heart. Slow down ALL your control inputs (wheel, gas, brake, clutch) and you will keep the car settled at all times, and thus able to provide maximum grip at all times. Then, it's up to you to USE all that available grip. Don't treat them like light switches, and you'll find yourself gaining pace pretty effortlessly.
Correct. The Factory unit is sufficient. The GT500 Unit is just more efficient. Tires and Suspension along with good brakes are critical to performance.
Yes, not exactly, and yes. The GT500 HCU isn't more efficient, it simply provides the hydraulic interface for an electronic module that is programmed for the type if braking we do on track. The stock GT HCU can't accept the Boss302S module, and the stock module was not programmed with sticky tires and repeated high-level braking events in mind. In the end, the brakes do NOT stop the car, but the tires do... And the suspension controls the tires.
The GT500 HCU/302S module is a high-end, race-ready setup, and is NOT required for track-day fun. It's so effective, that if you run that ABS setup in American Iron, it drops your power-to-weight ratio from 9:1 to 9.5:1. At the power levels of those cars, that's saying the 302S setup is worth the equivalent of 20RWHP. If you're running street tires, then you won't be touching more than a fraction of the capability of that setup. If I were in your shoes (and I was, believe me!), I would just work on proper braking technique until you start to learn where "the edge" is for your tire and suspension combo. Then focus on getting there EVERY time you hit the brake pedal.
As others have said, to disable this system you need to unplug fuses and such... not advised!!! The S197 ABS system is quite amazing and IS ALWAYS FASTER THAN NO ABS. Always. ALWAYS. 
