i need help, 924 or 944 brakes?

[chigger]

The tire loading determines your braking distance. Assuming you have good brakes. Even stock brakes will lock up the tires. You must learn to modulate the brakes so they are just before lock up to stop quickly. Bigger brakes make it easier to lockup the tires. The Ghia front disk with the T3 rears is what I am running and they will send you through the windshield if your seat belt is not on.
Since I decided to built a racing GL I went with 944 ventilated rotors and wilwood calipers. The early 944 configuration is excellent and is designed for a heavier car. Unless you are racing it is probably overkill. It is also very heavy.
Here in lays the problem. You want to have your car handle and stop. If you go with the GL look with the wider Porsche wheel and tire and Porsche brakes you will add a heck of alot of weigth to the unsprung weight of the car. This directly affects handling. You can assume about 10 lbs more for the front and rear brakes and another 10 lbs for the wheel and tire combination. This is actually conservative. A total of 20 lbs per wheel. This means you will need stronger torsion bars, bigger shocks and larger anti sway bars. With a cast iron hub adapter, aluminum caliper adapter, cast iron venlated rotor, and four puck aluminum calipers I have managed to get super braking with out the weight penality. I if I had used a modified 944 hub I would have gotten even more weight reduction which would have compensated for the ten lbs of increased rim and tire combination. Hope this helps.