Project Honda S2000 Part 3- Brakes that don't Break

Brake pads: bigger is better.  Be very careful driving until the StopTech Street Performance pads are properly bedded in.  They have minimal bite until bedded.

Another major advantage of the ST-40 caliper over stock is the size of brake pad used; the ST-40 uses a common Porsche size (back plate outline D609) which is significantly larger than the stock pad and comes in just about every pad compound known to man.  At the most basic level, bigger pads are like a bigger gas tank. You can do more braking before they are used up. Also, like a larger rotor, they have more thermal mass. For equal energy/heat input into the pads, the larger pads have less temperature increase. The difference here is small compared the rotor’s contribution to thermal management, but it’s still there. So this is one place where bigger is better!

The slotted StopTech rotor dwarfs the stock rotor and weighs less too!  We went with slotted versus cross-drilled as cross-drilled rotors are prone to cracking under heavy use.  The slots help evacuate vaporized pad material that the rotors can hydroplane on and lose effectiveness.  Honda likes to use two screws to secure the rotors to the hub; make sure you have an impact driver to break the screws loose to remove the rotors.

Advantage number two over stock: the rotors.  The stock front rotors are 300mm diameter, 25mm thick, and a straight vane design.  The StopTech 2-piece rotor is 328mm diameter, 28mm thick, and uses directional vanes; these directional vanes are StopTech’s patented AeroRotor vane design.  There are a few advantages associated with the increased rotor size. 

The larger diameter and the added thickness in the brake pad contact area means there’s a lot more mass in that area.  This is one place on a car where you want more mass as it means there’s more thermal capacity.  What do I mean by this?  Hell, while I’m busting out equations, here’s another one: Energy = Mass X Specific heat capacity X deltaT (change in temperature).  To slow the same car down from 100mph to 40mph requires converting the same amount of energy (motion to heat) regardless of the size of the brakes.  Specific heat capacity of a material is how much energy is required to increase the temperature of that material one degree.  Between the bigger rotors and smaller rotors, the energy and specific heat capacity are the same (assuming the same material), but the bigger rotors have more mass.  Therefore, their deltaT is lower. 

Bigger is better.  Bigger caliper, bigger rotor and bigger pads.  Bigger is also lighter, thanks to the use of aluminum rotor hat and caliper, instead of the stock cast iron and steel parts. With proper piston sizes, bigger is also balanced.