Brakes is not all about having the biggest brakes. Big brakes may brake better, and outbrake other cars, but might slow you down in turns and acceleration. Having 1 kg extra in wheels, brakes, hub is the same as adding 8 kg in the car, when you talk about how the car behave. And the longer away from the center, a rotating mass is, the slower your car brakes and accelerate. Try fitting 13" wheels, take a 0-62 mph time, then fitt 17" wheels, the 0-62 time is higher. If your brake setup can lock up every wheel in every corner of a track, then adding a bigger brake setup will only give you longer brake distance, slower acceleration and a car that fells heavy when changing direction. So taking 2 exactly the same cars and drives. 1 of them change to a bigger brake setup. He can now out-brake the other car, but he has lower turn speed and acceleration. Depending on the track, he will lose or win because of the brakes. K-sport and D2 brakes are big, they last long in pads and disc, they have very good stopping power, they dont heat up, but they are really heavy brakes. I had a D2 330 mm brake kit for my starlet. A mate bought a Brembo kit, 300 mm, for a Honda I think, and fitted on his starlet. They very a lot lighter, in calipers, and the disc. Of course 30mm less disc is lighter, but we are talking about 60% of the weight of the D2 kit. Run as small brakes and rims that you can, it will be overall faster on the track. Of course, you need to stop every time without problems and fast as well. For a 100% pure street setup, run big brakes. They might be heavy, but giving 0.1-0.2 bars of boost will counter the effect of the brakes. And you need to stop very fast when some dog jumps out in front of you.