As to the advice of “don’t buy presents for your car”…why?
Spend the money if you have a specific, known area you want to improve. Otherwise, save it until you do.
Let me remind you of a couple of things about brakes. First, the brakes don’t stop your car, the tires do that. Almost any modern braking system produces enough brake torque to lock the tires up at almost any speed you would dare to attempt that. Cars fitted with ABS systems can be pushed into activation with enough pedal pressure at almost any speed. Why therefore would you imagine you need more brakes when you already have enough brake torque to overcome the tires?
Bad reasons / logic for brake upgrades:
It looks cool to have big rotors and shiny red calipers. Yes, but they are also heavy and it takes power to accelerate them along with your wheels.
Bigger brakes stop the car in a shorter distance. No they don’t. Any brake torque beyond the point where the tires lock up is useless to you.
Bigger brakes up front only will increase the forward bias in your brake system and actually increase your stopping distance by pushing the front tires to the point of locking up while the rears wheels still have a lot more traction with which to stop the car, gone to waste.
Good reasons for brake upgrades:
On track days or long mountain descents my brakes overheat: First try pads with a higher heat range, then look into an oversize rotor kit.
Brake modulation is poor on sliding caliper brakes: Upgrade to fixed calipers with opposing pistons.
My old sliding calipers are worn out and sloppy: Good opportunity to upgrade but do your homework.
If you are running out of heat capacity in your brakes in street driving you could consider:
- Better brake pads like a performance street compound. Don’t even be tempted to run race pads on the street.
- If your car could stand the forward shift in bias, consider a kit with bigger rotors up front with a spacer to move your existing caliper to match.
- Since your car probably has too much forward bias as stock (as do most street cars), fit an opposed piston caliper with smaller piston area than stock on the stock rotor, which will move the bias toward the rear. You want to know what you’re doing here as a rear biased system is dangerous.
- Ditto above with larger, heavier front rotors.
- Ditto #4 with addition of oversized rear rotors as well.
If your car has drum brakes in the rear then job #1 is to swap for disks and upgrade pads front and rear.
But anyway, I’ll type this one more time. Bigger brakes will not stop your car sooner in an panic situation. Brakes with reduced front bias may stop the car sooner in an emergency, depending on the car, what tires you’re using and some other factors. Bigger brakes properly biased will help stop your car in a short distance stop after stop when the system is hot. Let me give an example.
Two identical cars with the same suspension and tires, pressures etc. One has the stock factory brakes and the other the huge million $ bling bling floating ceramic disks plus high-dollar 6-pot front calipers and 4-pot rears, fitted with high performance pads. Both cars going 100kph, slam the brake pedal down until the ABS system kicks in. Both cars will come to a stop in almost exactly the same distance because the sole determining factor here is traction. Both cars now accelerate back to 100kph, side by side, and repeat the test. This time the blinged out car stops a few feet shorter. Repeat again and the standard car takes 10’ longer to stop and the brakes smell… hot. Do this a fourth time. The bling car stops in the same distance as the first time and will do so all day long if you want to keep going. The standard car didn’t set off the ABS and took 20’ longer to stop than the first time, the pedal feel is all mushy and there is a foul smell and a little smoke coming off the brakes.
You will only ever need this kind of a brake system if you are driving the car very hard on mountain roads or at the track, or unless you like going around at full speed everywhere and making emergency stops every 100’. If you had that kind of need I think you’d have come here complaining about smelly, fading brakes, hence the comment about presents.
Some more [url=http://tw.forumosa.com/t/brake-rotor-size-redux/31870/1 on brakes[/url].
Hope this helps.[/quote]
i’ve been telling all my friends " First, the brakes don’t stop your car, the tires do" for a long time , exact words too.