i think both are very important to condsider. i just went from stock brakes to The Brake Man front brake kit. but the more tire traction you have (ie compound and width of the tire) will allow the use of more clamping force on the brakes without locking up the wheels. i might be wrong but the fastest the car will stop is when you are on the verge of locking the wheels up but not quite there. so if you are on a hard compound of a tire you will not need as much clamping force as if you were on race tires that will not lock up even under tons of clamping force. My stock brakes could very rarely lock up my wheels (initiate abs) except at very low speeds. and on the race track with street or race tires it didnt even have a chance. so in that manner i believe that the stock braking power is well below the allowance of clamping force that any tires would require to be effective. My brake kit however will over power my street tires and go straight to abs at any point or speed on the road. and if that is all anyone is doing... overkill (somewhere in between would be ideal). but on race tires when heated up... its beautiful. it doesnt go to abs easily and allows to use the full traction of the tire to stop the car. that is where you feel the HUGE difference in stopping power. i hope that made sense and someone correct me if i made any bad points.
