Wilwood 120-11331 Forged Superlite Internal 4-Piston Caliper with 4-Bolt Mount, Right Hand

Forged Superlite Internal 4 ST

FSLI4 and FSLI4/ST calipers offer the pad wear performance advantages of differential bore pistons with the option of maximum thermal protection from Thermlock® pistons on ST models. Differential piston bores compensate for leading edge mechanical loads and temperature variations across the pad face to reduce tapered pad wear in sustained high-heat applications. Thermlock® pistons in ST models block heat transfer from the pads and reduce caliper, fluid, and seal temperatures by as much as 25% over standard stainless steel pistons.

These are the ideal brake calipers for all types of severe duty and sustained braking on dirt and asphalt ovals, as well as a wide range of off-road, rally, and road course applications. The new FSLI4 and FSLI4/ST models incorporate the latest innovation to the Superlite caliper family. They have been re-engineered with internal fluid ports that eliminate external fluid transfer tubes, along with any potential problems that can arise from a damaged tube. The transfer tube has been replaced with two additional bleeder screw assemblies that allow this group of differential piston calipers to be mounted right or left, front or rear. The outstanding feature of all FSLI caliper models is the exceptional strength and light weight of the forging. Weighing a mere 4.4 pounds, the caliper body design itself is a product of computer generated solid modeling and stress analysis technology. Each caliper features closed-end bridges with a radial transition into the main body and piston housings. The elimination of machined steps and sharp shoulders in this critical area provides a significant increase in overall body strength and resistance to deflection under load. Each FSL body is stress-flow forged from a premium grade aluminum alloy billet. This process re-aligns the internal grain structure of the metal to flow with the contour of the caliper body. This process eliminates the stresses and interruptions to internal grain structure that occurs when machining a straight block billet. class="Gray11B">Thermlock Dust Boot No

Rotor Dimensions

Rotor Width (in)	1.25
Rotor Diameter (in)	13.06

Pad Dimensions

Pad Area (in²)	8.2
Pad Volume (in³)	4.9

Service Rating & Material

Material	Forged Aluminum
Weight (lbs)	5.2

Colors & Finish

Color	Anodized
Finish	Type III Anodized

Mounting

Mounting Center (in)	3.50
Mounting Position
Mounting Side	Right
Mounting Type	Lug

Specifications

Rotor Compatibility

Rotor Width (in)	1.25
Maximum Rotor Width (in)	1.38
Minimum Rotor Width (in)	1.19
Maximum Rotor Diameter (in)
Minimum Rotor Diameter (in)	11.75

Brake Pad Specifications

Brake Pad Type 1	7420
Brake Pad Type 2	N/A
Brake Pad Type 3	N/A
Total Pad Area (in²)	8.2
Total Pad Volume (in³)	4.9
Mounting

Piston

Piston Specifications

Piston Bore 1 (in)	1.88
Piston Bore 2 (in)	1.75
Piston Bore 3 (in)
Total Piston Area (in²)	5.18

Mounting Specifications

Mounting Type	Lug
Mounting Side	Right
Mounting Center (in)