Quote:
Originally Posted by
kwtoxman
I don't think it is simple as the last few posts.
If the base brakes can hold the tires at the limit of braking through the entire braking distance then larger rotors and brakes won't help. I doubt GM built the solstice brakes in a manner where it couldn't brake the car at the limit of braking in a typical cold (street) scenario. Imagine the liability issue alone. And the fact that it isn't hard to engage the antilock on the car (ie the limit of braking performance where tires are the the limit in braking performance). In a street drive (cold) I doubt braking distance would significantly improve.
The real advantage with larger brakes and rotors comes in when hot, which is typical track/racing use.
As mentioned reciprocating mass matters. Larger brakes increase reciprocating mass hindering braking ability in some regards.
All IMO
kw.....
Not sure if anybody still had questions about how brakes work (I’m not picking on kwtoxman, he was just the last one to post on the topic

)
The only thing that truly "stops" your car is the tires. The contact patch of the tire is where the opposing forces act to slow your car down.
So the only way to improve your stopping distance, if current brake system can lock the wheels up, is getting stickier tires.
You calipers are not stopping the car. They are converting kinetic energy into heat energy (energy cannot be made or destroyed, only converted). And the larger BBK kits usually can manage/dissipate heat better. So they can perform threshold braking for longer periods of time (i.e. road racing).
The BBK kits that increase the effective radius of the rotor [ (outer contact radius - inner contact radius)/2 ] will not make your car stop any faster. BUT, they will decrease the pedal effort needed by the driver to stop. This is why people think they are stopping faster, because they didn't have to push the pedal as hard.
This is part of the brake system "gain". other items that effect the gain is the size of the vacuum brake booster, the lever ratio on the brake pedal, the size of the master cylinder piston compared to the caliper piston size, the overall size of the tire (shorter tire = easier to stop)
Now if your car has a really crappy brake system and you cannot lock up the wheels (with ABS disable) then a BBK will help you stop faster because you were never able to get to the peak tire braking force. This should be over 1 g of deceleration achieved between 10% and 30% slip depending on the tire (100% slip is a locked wheel).
Alex