"If you go from stock, to 400whp, upgrading the brakes, IS NOT NEEDED AND YOU WILL BE NO SAFER THAN YOU WOULD BE ON STOCK BRAKES."
This comment bothers me and quite frankly is dangerous IMO. The type of person who upgrades their car to 400whp likely is not staying in the garage polishing it. While I agree the most measurable upgrade would be tires, there are several factors that are being left out. Say this person with a 400whp car enjoys a nice twisty mountain road. His old 200whp WRX would get up to 70 MPH, he would brake, rinse, repeat. Now insert the 400whp car. Instead of 70 MPH, suddenly he is up to 100 MPH, he would brake, repeat and insert fade. If you were to have your $3 bottle of Autozone fluid in there, you would have a long time to wave goodbye as you roll down the mountain. The problem with the argument is that you are looking at braking as an isolated incident. Many times, yes that is true. However, a higher horsepower equal higher attainable speeds which puts a higher strain on the braking system. The fact that this is stickied on the newbie thread made me want to make that point. DISCLAIMER:driving your car at speeds that are dangerous and above speed limits are dangerous. If your car is built to just putt-putt around town (re:legal) then those statements of the OP are true.