Hawk HB521N.650 HP Plus Brake Pads for AP Racing CP8250 Wilwood Superlite

Vehicle Fitment

This is a universal racing caliper brake pad. It is not vehicle-specific and is not sold for use with OEM stock calipers. Fitment is determined by caliper model. Compatible racing calipers include:

• AP Racing CP8250
• AP Racing (Essex) CP8350-24S4L / CP8350-25S4L / CP8350-26S4L / CP8350-27S4L / CP8350-32S4L / CP8350-33S4L
• CompBrake Pro Race One
• StopTech ST-43 / C43
• Wilwood Narrow Superlite 4 / Narrow Superlite 6 (plate shape 7416)
• Wilwood Superlite Bridge Bolt
• Wilwood Superlite 4R / Superlite 6R (plate shape 7416)
• Wilwood Superlite ST
• Wilwood Forged Superlite Internal

Fitment Notes

• This pad is universal for racing calipers - it is not designed for OEM stock brake calipers and has no vehicle-specific fitment.
• Pad thickness: 0.650 in. This corresponds to Wilwood plate shape 7416. The same pad shape is also available in 0.800 in. thickness (Wilwood plate shape 7420 / AP Racing CP8250D41); verify your specific caliper's required pad thickness before ordering.
• Some Wilwood Superlite calipers use the bridge bolt retention method, which requires a center mounting hole in the pad. Depending on the specific caliper configuration, the center hole may need to be drilled - verify your caliper's pad retention method before installation.
• Not compatible with carbon ceramic rotors. For use with iron/metal rotors only.
• HP Plus is an autocross and track day compound that delivers more initial bite and fade resistance than HPS at the cost of increased dust and noise. It is streetable for dual-use driving but is not optimized for quiet, low-maintenance daily use.
• Sold as a set of two pads (one caliper). For a full brake system upgrade, one set per caliper is required.

Features

• HP Plus Ferro-Carbon compound - Hawk's benchmark autocross and track day formulation for the AP Racing CP8250/CP8350, StopTech ST-43, and Wilwood Superlite caliper family, delivering fade-resistant high-torque braking across the full performance driving envelope while remaining streetable for dual-use owners who drive to and from events without changing pads.
• Wide operating temperature range - 100-800°F total range with a 300-600°F optimal window, providing effective brake torque from cold ambient starts through sustained hard braking at autocross events, HPDE sessions, and track days - the full thermal range encountered by dual-use street and track performance vehicles equipped with these aftermarket calipers.
• Strong cold bite from the first application - Delivers effective brake torque from ambient temperature without a heat warm-up cycle, making it practical for autocross competition where session lengths are short and pads may never reach the higher temperature ranges required by pure race compounds to perform optimally.
• Fade resistant under repetitive hard braking - Sustains consistent, high brake torque across back-to-back hard stops at autocross runs and track sessions, maintaining performance well beyond the point where HPS and standard street replacement compounds begin to fade in the larger AP Racing, StopTech, and Wilwood calipers.
• Smooth and predictable torque - The HP Plus compound's progressive engagement supports confident trail-braking and threshold braking, giving drivers precise modulation through the larger pistons of these aftermarket racing calipers without the abrupt bite of DTC-series race compounds.
• Lower rotor wear than dedicated race compounds - The HP Plus Ferro-Carbon formulation produces significantly lower disc wear than DTC-60 and DTC-70, extending rotor service life across competitive seasons and multiple track days - a meaningful benefit given the cost of the premium rotors typically used with AP Racing and Wilwood caliper installations.
• Streetable for dual-use driving - Designed to be driven on public roads to and from track events, making it the natural compound choice for big brake kit owners who compete at autocross and HPDE events but do not want to change pads between street driving and competition. Expect more dust and potential noise compared to the HPS compound.
• Step up from HPS for more demanding use - For big brake kit owners who have used HPS and need more front brake torque at track days or higher-speed autocross events, the HP Plus provides a meaningful step up in fade resistance and sustained performance while remaining a dual-use compound.
• 100% asbestos, lead, chromium, cadmium, and antimony free - Manufactured in an ISO-certified facility to strict quality and environmental standards.

Specifications

• Part Number: HB521N.650
• Compound: HP Plus
• Compound Code: N
• Friction Material: Ferro-Carbon
• Pad Thickness: 0.650 in. (Wilwood plate shape 7416)
• Total Operating Temperature Range: 100-800°F
• Optimal Temperature Range: 300-600°F
• Caliper Compatibility: AP Racing CP8250 / CP8350 (Essex); CompBrake Pro Race One; StopTech ST-43 / C43; Wilwood Narrow Superlite 4 / Superlite 6 / Superlite Bridge Bolt / Superlite 4R / Superlite 6R / Superlite ST / Forged Superlite Internal (7416 plate shape)
• Rotor Compatibility: Iron/metal rotors only - not compatible with carbon ceramic rotors
• Recommended Use: Autocross / Track Day / HPDE / Dual-Use Performance Street
• Sold as: Set of 2 (one caliper)

Included Components

• 2x Hawk HP Plus Brake Pads (HB521N.650)

Product Description

The Hawk HB521N.650 HP Plus brake pads bring Hawk's benchmark autocross and track day compound to the HB521 pad shape at 0.650 in. thickness, fitting AP Racing CP8250 and CP8350 (Essex), CompBrake Pro Race One, StopTech ST-43/C43, and the Wilwood Superlite family of racing calipers using the 7416 plate shape. In the compound progression available for the HB521 shape, HP Plus sits between HPS and the DTC-series race compounds - delivering more initial bite, greater fade resistance, and a higher temperature ceiling than HPS, while remaining streetable and avoiding the cold-bite and noise limitations that make pure race compounds impractical on a daily-driven performance car.

For owners of AP Racing, StopTech, and Wilwood big brake kit installations who compete at autocross events and attend HPDE sessions, the HP Plus is the natural progression from the HPS. It operates from 100-800°F (optimal: 300-600°F), covering the full thermal range of competitive autocross runs and track day sessions where HPS compounds approach their ceiling. The compound's strong cold bite means effective torque is available from the first run of the day without a warm-up lap, which is particularly valuable in autocross competition where individual runs begin from a cold brake state. For track day use, the sustained fade resistance across back-to-back sessions delivers the consistency that HPS cannot maintain at higher ambient temperatures and more aggressive driving paces.

At 0.650 in. thickness, this pad is specific to the Wilwood 7416 plate configuration. The same HP Plus compound is available at 0.800 in. thickness for 7420-plate calipers (HB521N.800). Verify your specific caliper's required pad thickness and retention method - bridge bolt Wilwood configurations may require a center hole to be drilled in the pad. Compatible with iron and metal rotors only; carbon ceramic brake discs are not supported.