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

The StopTech caliper has a stiff forged alloy body and is radially mounted, this is a stiffer more direct way to mount calipers.

Advantage number one over stock: the calipers.  The stock front calipers on the S2000 are a single piston, sliding design.  Yes, they stop the car, but they leave a lot to be desired in feel.  The caliper is prone to flexing which can make for inconsistent pedal effort.  Also, being only single piston, the pressure distribution on the pads between each side and on each pad them self can be uneven.  Lastly, if not maintained, it’s possible to get the ‘sticky’ caliper where the ‘slide’ part no longer functions.  This basically results in only one pad doing all the work and one pad getting all the wear.  The dragging pad will also run much hotter, possibly damaging the pad, rotor and caliper. The StopTech calipers, having 4 opposed pistons have nothing to ‘stick’ or drag!

Installing brake pads is a snap!  Just remove the two 5mm allen head bolts, take off the caliper bridge and the pads are accessible.  This is MUCH easier than the standard Brembo setup that requires knocking out two long pins, using something pointy and a hammer, and then dealing with a pad retention spring.  Oh, and putting the pins back in on the Brembos is a pain too.

A very important advantage of Stoptech calipers is that the proportioning of their systems is calculated to match the S2000's hydraulic system.  On stock single master cylinder brake hydraulic systems, the brake's proportioning is mostly determined by the caliper piston size.  The larger the piston the greater the hydraulic force applied to the brake pad, the smaller, the less.  Stoptech duplicates the OEM proportioning using 19 different possible combinations of piston sizes. Stoptech has the greatest spread of piston sizes available on the market and thus can come the closest towards duplicating the correct proportioning when compared to other manufacturers. Many things are considered when choosing piston sizes; stock master cylinder bore diameter, car size and weight, weight distribution, brake pad size, rotor size, tire size and wheel size.

The StopTech calipers have dust boots to protect the seals unlike many race calipers and have stainless steel abutments to protect the alloy body from the steel brake pad backing plates.  This ensures smooth operation.

The StopTech ST-40 caliper is way beefier and a 4-piston design; two pistons for each brake pad.  The super stiffness of the forged aluminum caliper improves feel and consistency, while the 4-piston design greatly improves the pressure distribution on the pads; more even pressure distribution should improve pad wear and feel consistency.  An important aspect to the piston sizing is using different sized pistons on the leading and trailing sides of the brake pad to eliminate taper wear (where the leading and trailing sides of the pads wear at different rates); this is good practice as even the OEM calipers on a Honda CBR 600RR sportbike have pistons with differential sizing.  Taper wear is caused by the leading edge of the pad digging in and causing a tipping moment that increases pressure and wear on the front side of the pad. 

Unlike most other racing brake calipers, the StopTech caliper has dust boots to protect the seals during long term street driving from abrasive pad dust, water and other potentially damaging contaminants.

We used a set of StopTech's Street Performance brake pads.  These semi metallic pads are long lasting, quieter and lower dusting than race pads and work well at lower temperatures.