Perrin PSP-ENG-111RD Lightweight Water Pump Pulley Red for 2015-2021 Subaru WRX

Vehicle Fitment

• 2015-2021 Subaru WRX (FA20DIT 2.0L Turbo H4, AWD)

Fitment Notes

• Fits all FA20D and FA20DIT (turbocharged) engine variants in the listed model years - these engines share the same water pump pulley mounting configuration
• Does NOT fit the 2022+ Subaru WRX (FA24F engine) - a different Perrin part number (PSP-ENG-112) is required for the 2022+ WRX
• Does NOT fit the Subaru WRX STI (EJ257 engine) - the STI uses a different engine platform with a different water pump pulley specification
• Sold individually - 1x water pump pulley per package; replaces the OEM water pump pulley only (not a full water pump assembly replacement)
• Estimated installation time: approximately 30 minutes using basic hand tools
• Warranty: 5-year limited from Perrin Performance (original purchaser, vehicle not transferred, non-racing use)

Features

• Reduces rotating mass at the water pump - at 0.48 lbs, the Perrin pulley is 0.28 lbs lighter than the OEM water pump pulley (0.76 lbs), directly reducing parasitic drag on the engine's accessory drive system
• Reducing rotating mass from the accessory drive is equivalent in effect to removing significantly more static vehicle weight - any reduction in rotational inertia at engine speed translates directly into faster throttle response and improved power delivery to the wheels
• Improves throttle response, horsepower, and torque - the weight reduction is immediately felt in the engine's willingness to rev and respond to throttle inputs
• Machined from 6061T6 billet aluminum - the same aerospace-grade alloy used throughout Perrin's lightweight pulley line, providing superior strength-to-weight ratio over OEM cast alternatives
• Laser etched surface - the precision etching increases belt grip on the pulley surface for improved belt life and reduced belt slip over extended use
• Anodized red finish - a hard anodize coating that provides corrosion resistance, prevents oxidation in the engine bay environment, and maintains appearance under heat cycling over years of use
• Simple installation - replaces the OEM water pump pulley with only basic hand tools in approximately 30 minutes; no special tools or engine teardown required
• 5-year limited warranty from Perrin Performance - one of the longest warranties in the aftermarket pulley segment

Specifications

• Part Number: PSP-ENG-111RD
• Product: Lightweight Water Pump Pulley
• Color / Finish: Red anodized
• Material: 6061T6 billet aluminum
• PERRIN Pulley Weight: 0.48 lbs.
• OEM Pulley Weight: 0.76 lbs.
• Weight Savings vs. OEM: 0.28 lbs. lighter
• Surface Treatment: Laser etched + anodized
• Estimated Install Time: 30 minutes
• Warranty: 5-year limited (60 months from date of purchase)
• Quantity: Sold individually (1x water pump pulley)

Included Components

• 1x Perrin PSP-ENG-111RD Lightweight Water Pump Pulley (Red Anodized)
• Warranty card and installation instructions

Product Description

The Perrin PSP-ENG-111RD is a lightweight billet aluminum water pump pulley engineered for the 2015-2021 Subaru WRX and other FA20-platform Subaru models. It is a direct OEM replacement for the factory water pump pulley - the same pulley that spins at engine RPM every time the accessory belt is turning. By swapping the OEM pulley (0.76 lbs) for the Perrin version (0.48 lbs), the driver removes 0.28 lbs of rotating mass from the accessory drive system. While that number sounds modest, rotational mass reduction at engine speed has a disproportionately large effect on engine response compared to an equivalent reduction in static vehicle weight - the lighter pulley requires less energy to accelerate, which translates directly into faster throttle response and marginally improved power delivery to the wheels across the full RPM range.

The pulley is machined from 6061T6 billet aluminum - the same alloy used in aerospace structural components - which provides the structural integrity to handle continuous accessory belt loading while delivering the weight reduction that cast OEM pulleys cannot achieve. The machining process produces a precision-dimensioned pulley that fits the factory water pump shaft and belt geometry without modification. Laser etching on the pulley surface increases belt grip and extends belt life by preventing slippage at the contact surface. The hard red anodize coating seals the aluminum against corrosion, heat cycling, and oil contamination in the engine bay environment, maintaining the appearance and structural surface integrity over years of use.

Installation is straightforward and requires no special tools - most owners complete the swap in approximately 30 minutes. This part fits the FA20D and FA20DIT engines found in the 2015-2021 WRX, dedicated Perrin pulleys exist for those applications. Perrin backs this pulley with a 5-year limited warranty from the date of purchase, making it one of the longest warranty periods available in the aftermarket lightweight pulley category.