Lightweight, monobloc, underdrive, keyed, steel crankshaft pulley kit. CNC machined. Fits Ford EcoBoost 2.3L and 2.0L engines (Ford Mustang, Ford Focus RS, Ford Focus ST, Ford Ranger, Escape, Edge, Explorer, Fusion) - Could fit Mazda 2.3L DISI and Ford Duratec engines with motorsport ("standalone") ECU able to work with the 60-2 EcoBoost tooth pattern.

• Low inertia all-steel crankshaft pulley in one solid metal piece (CNC billet).
• AC delete - Perfect for your track or autocross car.
• Chromoly (41xx) alloy with electro-chemical anti-corrosion treatment.
• 20% underdrive (reduces high-RPM parasitic losses from alternator and water pump -> frees up horsepower and reduces risk of high-RPM water pump cavitation.)
• A/C delete.
• 3mm keyway (ISO R773) for keyed crankshafts (key at TDC#1)
• Integrated precision-machined 60-2 crankshaft sensor trigger.
• Designed for ARP M14x1.50 bolt (supplied)
• Designed for Callies Lightened Keyed Crankshaft (QH47KWO-F2) also sold by Mountune USA and Panda Motorworks.
• Fits standard Ford 2.3/2.0L and Ford Performance M-6303-23EB crankshafts (requires new Ford 1S7Z-6378-AA friction washer)
• Fits Massive Speed Systems and SP63 OEM-based keyed crankshafts.
• Fits Arrow Precision Engineering C146/C147 forged motorsport crankshafts.
• The kit includes every parts needed for installation::
• New lightweight motorsport steel crankshaft pulley ~684g (~1.5lb)
• New lightweight motorsport steel water pump pulley ~170g (~6oz)
• New genuine ARP 251-2501 high-tensile reusable M14x1.5 bolt.
• 7g (¼oz) CMD #3 anti-scoring assembly grease for use with ARP bolt.
• New matching Gates RPM® MICRO-V® racing performance accessory belt, aramid-reinforced for low stretch and long service life. 
• Printed installation guide.
• Precision engineered, precision machined, durable and perfect fit.
• Exact machining of the Micro-V belt race and exact mating with the crankshaft. The belt does not slips nor skips and we paid special attention to the crankshaft interface, with a tight fit for optimal centering and solid contact. Aluminum alloy pulleys crush under the required tightening torque and become loose after a few heat cycles, which is a source of severe issues. Our steel pulley guarantees the proper mechanical fit and can be torqued to ARP specs without fear.
• The kit comes with a suitably shorter belt. Replacement belts are available off-the-shelf from Gates for regular maintenance, with many equivalent references available from most auto part suppliers.
• Total weight reduction compared to stock: approx. -1.96kg (-4.33lbs)
• Approx. 20% parasitic losses reduction from accessories (water pump, alternator) at high RPM. While difficult to quantify in terms of equivalent HP gains, top-level race cars have power distribution units (PDUs) that disconnect the alternator under acceleration to free a little bit of power, so those losses matter.
• Lower inertia for faster engine response. While also difficult to quantify in terms of equivalent HP, inertia fights acceleration so the less the better.
• Save an additional 6.8kg (14.8lbs) by removing the AC compressor and main pipes, more by also removing the front-mount AC condenser.
• Designed in Washington State, U.S.A.

Pictures shows computer renderings of the crankshaft pulley and water pump models, as well as the zinc electroplated prototypes used to validate the mechanical design used for on-vehicle testing. Production parts will be available in Spring 2024. Final appearance and finish may vary.