Wilwood Caliper-Forged Superlite 1.25in Pistons 0.81in Disc

Wilwood Forged Superlite FSLI Caliper with Symmetrical 1.25-Inch Pistons for Short Track and Road Race

The Wilwood WIL120-11126 is a Forged Superlite FSLI single caliper with dual symmetrical 1.25-inch pistons and a 0.81-inch disc width capacity. The Forged Superlite series is the benchmark in short track, late model, modified, and open wheel competition, and sees equal prominence in road race, off-road, rally, and high-performance street applications. The FSLI update to the classic Superlite body routes brake fluid internally between the two piston bores, eliminating the external crossover tube used on earlier models and removing a potential leak or damage point from the caliper. Two bleed screw assemblies replace the crossover tube, allowing all symmetrical bore models to be mounted in any combination of left, right, leading, or trailing positions without rerouting fluid lines. The WIL120-11126 is sold as a single caliper. The 1.25-inch piston bore size sits between the 1.12-inch and 1.38-inch options in the FSLI series, providing a slightly higher clamping force than the 1.12-inch variant with the same 0.81-inch rotor width.

Key Features

• Internal fluid ports eliminate external crossover tube for a cleaner, more durable design
• Two bleed screw assemblies allow leading or trailing, left or right mounting in any position
• Symmetrical 1.25-inch piston bores for uniform clamping pressure
• Fits 0.81-inch wide rotors
• Forged billet aluminum caliper body for maximum strength-to-weight ratio
• Suitable for short track, late model, open wheel, road race, rally, and street performance
• Sold as a single caliper

Specifications

What's Included

• 1 x Wilwood WIL120-11126 Forged Superlite FSLI caliper
• Bleed screws installed

Related Parts on Our Site

• Wilwood 120-11125 — Forged Superlite FSLI 1.12in Pistons, 0.81in Disc
• Wilwood 120-11128 — Forged Superlite FSLI 1.38in Pistons, 0.81in Disc
• Wilwood WIL220-7496 — 1/4-28 Black Bleed Screw (replacement for this caliper)

About Wilwood

Wilwood Engineering has been designing and manufacturing high-performance brake components in Camarillo, California since 1977. Every Wilwood caliper is machined from premium forged billet aluminum and validated through motorsports testing. Wilwood products are trusted by professional teams across SCCA, NASA, and multiple short track and oval disciplines.

Frequently Asked Questions

The Wilwood WIL120-11126 is a Forged Superlite FSLI single caliper with dual symmetrical 1.25-inch pistons and a 0.81-inch rotor width capacity. It features internal fluid ports that replace the external crossover tube, and two bleed screw positions for flexible left or right, leading or trailing mounting.

A larger piston bore generates higher clamping force for the same line pressure. The 1.25-inch WIL120-11126 produces more clamping force than the 1.12-inch WIL120-11125 and slightly less than the 1.38-inch WIL120-11128, all at the same 0.81-inch rotor width. Choose the piston size based on your application's required braking bias and total system clamping balance.

Yes. The symmetrical piston bore and dual bleed screw design allow the WIL120-11126 to be mounted in a leading or trailing position on either the left or right side without rerouting fluid lines.

No. The WIL120-11126 is sold as a single caliper. Order two for a complete axle application.

The WIL120-11126 fits 0.81-inch wide rotors. Confirm your rotor width matches this specification before ordering.

Wilwood Superlite FSLI calipers use 1/4-28 threaded bleed ports. The Wilwood WIL220-7496 bleed screw is the correct replacement part for this caliper.

The Forged Superlite accepts a wide range of Wilwood BP-10, BP-20, and BP-30 series pad compounds as well as many third-party pads in the correct caliper width and mounting tab pattern. Consult Wilwood's pad selection guide for the correct pad for your rotor size, weight class, and usage.

Yes. This is a universal racing caliper that requires an application-specific or custom bracket to locate it correctly relative to your rotor. Wilwood offers a wide range of application-specific brackets, or the caliper can be used with a fabricated custom bracket sized for your rotor diameter and offset.

Installation Instructions

1. Confirm rotor width (0.81 in) and bracket offset before ordering. Source or fabricate the appropriate mounting bracket for your application.
2. Mount the bracket to the upright or knuckle and torque to specification.
3. Install brake pads into the caliper. Position the caliper over the rotor on the bracket.
4. Torque caliper mounting bolts to bracket specification. Verify even pad-to-rotor clearance on both sides.
5. Connect the brake line to the inlet port with a new copper sealing washer. Torque the fitting to specification.
6. Bleed the caliper from the outboard bleed screw and confirm a firm, consistent pedal before driving.
7. Bed in pads following the manufacturer's procedure before hard braking use.