Wilwood Caliper-Forged Superlite 4 1.88/1.75in Pistons .81in Disc

This is the Wilwood Forged Superlite 4 brake caliper, part number 120-11138. It's built for serious braking performance, especially in demanding situations like off-road racing, rally, or road courses where sustained hard stops are common. The caliper uses differential bore pistons, meaning it has two different piston sizes (1.88-inch and 1.75-inch) working together.

The reason for the different piston sizes is to help manage how the brake pad wears down. In hard braking, the leading edge of the pad can get hotter and mechanically loaded differently than the trailing edge. These differential bores help compensate for those temperature and mechanical variances, which reduces uneven pad wear, also known as taper wear. This means you get more consistent performance and longer pad life, even when you're pushing your vehicle hard.

While this specific model doesn't feature the Thermlock® pistons for extreme heat management, it's still a well-built caliper designed for high-performance braking. It's a solid option if you're looking to upgrade your braking system for more demanding use.