An important advantage of Stoptech calipers is that the proportioning of their systems is carefully calculated to match the Spec-V’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.
|13″ Stoptech Aerorotors have alloy hats so they end up being lighter despite being much bigger and thicker than stock.|
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. Another 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). 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.
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. With bigger pads you can do more braking before they are used up. Also, they have more thermal mass. For equal energy/heat input into the pads, the larger pads have less temperature increase.
|You can see the staggered vanes on the Aerorotors here as well as the vanes on the aero hats. These help keep things cool and in the case of the hat, reduce heat transfer.|
We replaced the stock Nissan front rotors with Stop Tech AeroRotors. The StopTech 2-piece rotor are 328mm diameter, 28mm thick, and uses 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. This is one place on a car where you want more mass as it means there’s more thermal capacity. Another key feature of the StopTech AeroRotor are their directional vanes. The directional vanes induce greater cooling air flow (as compared to the stock straight vanes) through the rotor which reduces its operating temperature. Directional vanes tend to interrupt the propagation of radial cracks, making for an inherently more durable part than the stock, straight-vane rotors.