Wilwood Rear Blank-Flange Drag Hat for Eight-Bolt Rings, 1.590-Inch Offset

This Wilwood rear drag hat uses 1.590-inch offset and an eight-bolt rotor connection. Confirm the blank flange's machining layout and hub register. Wilwood Engineering, founded in 1977 by Bill Wood, is based in Camarillo, California. The company designs and manufactures disc brake systems and supplies master cylinders, calipers, brake rotors, valves, fittings and lines for motorsport, street-performance and specialized installations. Select each component around the complete system’s requirements.

Technical Details

• Manufacturer part number: 171-3755
• Manufacturer-listed attachment hardware reference: 230-0233D; verify the specific rotor and attachment arrangement before ordering hardware
• Rotor-bolt clearance: The listed 230-0233D kit uses short-profile hex-head bolts for the solid-rotor drag assembly. Use 230-2589 only where the installation provides sufficient clearance between the rotor-bolt heads and caliper mounting hardware.
• Manufacturer installation note: 3.06 " diameter register with counterbore for register ring.
• Component: Drag Brake Rotor Hat
• Material: Aluminum
• Surface finish: Black E-Coat
• Rotor mounting method: Fixed Mount
• Position in the specified brake assembly: Rear
• Hat offset: 1.590 inch
• Rotor attachment interface: 8 x 7.00 inches; rotor attachment, separate from the hub flange
• Hub-flange mounting/clearance pattern(s): Blank — flange requires machining
• Center register diameter: 3.06 inches
• Rotor mounting hole/thread designation: 5/16-18
• Internal clearance diameter: 6.14 inches
• Mounting-face thickness: 0.25 inches

Fitment & Compatibility

This is a component for Custom drag brake systems, not a complete brake kit. Check the hub location, rotor mounting surface and caliper alignment as a system before ordering. The blank hub flange is not ready to bolt on. Have a qualified machinist verify the drilling layout, register and finished mounting surfaces for the intended assembly.

Manufacturer Reference

Wilwood component specifications and dimensions · Wilwood 230-0233D / 230-2589 hardware-clearance reference

For fitment assistance backed by more than 20 years of experience, share the installed brake configuration with PMB Performance before ordering.