Kozy

I see brake thread. Must. Resist. Getting involved.

Failed.

In terms of "why am I on this forum", I was looking to get an S2000 a couple of years ago so signed up, but haven't really got involved since my insurance premiums are determined to keep me in an MX5 for the time being!

lower

And that is the point I disagree with. The human factor has nothing to do with it. With higher coefficient pads or bigger discs it is possible to get closer to the limit of the tyre's grip and therefore stop faster.

Kozy

Sorry, but that makes no sense at all. Why?

Are you suggesting you can't get to the lock point with OEM pads? If so, I see your argument, but that's simply not true. No car manufacturer sells performance cars with brakes that cannot deliver that level of force.

MIP

The point is, you can already go to the tyre limit and beyond with the OEM pads. If you hit ABS, you are at the limit of the tyre. That is a fact of physics, your braking force has overcome the force of the road trying to roll the tyre. If the tyre was stickier, it wouldn't and ABS wouldn't kick in.

And it's not correct to assume a better pad has a higher coefficient of friction. A good brake pad will have constant coefficient across a wide temperature range. A higher coefficient will require less pedal pressure for the same braking, but will generate more heat and possibly fade.

lower

The fact you can lock the wheels doesn't mean you have the ultimate braking system. There is much more to it than that.

The point i keep trying to make is that ultimate braking performance happens just before the tyre loses grip and locks. What better pads and larger discs give you is the ability to modulate the braking force more easily and therefore get closer to the lock up point and brake harder before the wheels lock.

With OEM pads the force applied by the pedal pressure and therefore piston pressure on the pads is very high at the point that the wheels lock and you don't have the ability to modulate that pressure easily. Therefore you go from using 90% (don't know the exact figures, just using the percentages for illustration) of the tyres available grip under braking to virtually instantly over 100% (when the wheel locks) and you can't modulate the brake pressure effectively in that 10%. So in effect you only actually use 90% of the available grip before the wheel suddenly locks.

Higher coefficient of friction pads require less pedal and piston pressure for the same braking effort and therefore means you can modulate the pad pressure much more easily. This means you can use more of that remaining 10% of the available grip before the wheel locks and therefore stop faster. You get the same effect by increase the disc size and therefore get more leverage or by changing the master cylinder/brake caliper piston size ratio.