Under the Hood of the 600hp AWD Ford Focus RS RX Rallycross Car

The Hoonigans are back to take a look at the mechanics of our partner Steve Arpin’s ARX competition vehicle.

The background:

Steve Arpin | Global Rallycross | New England - Thompson CT 2017

Steve Arpin | Global Rallycross | New England – Thompson CT 2017

  • Steve Arpin started in Rallycross (the former GRC) in 2015 (partnered with ENEOS)
  • He took 3rd place overall in the final year of GRC in his Ford Fiesta 00
  • Starting this year, Steve has partnered with Ken Block and his Hoonigans Racing Team
  • Currently drives a custom, expertly-crafted and tuned 600 hp Loenbro Ford Focus 00 Rallycross race car

Vehicle facts:

  • Body is all carbon/kevlar mix; only the roof and driver’s door are steel (for safety)
  • 1300 kg (2866 lbs) total weight (including driver)
  • Weighted in specific places for optimal balance
  • Designed by Ford and M Sport, re-engineered by Loenbro Motorsports
  • 100% purposefully built for Rallycross


  • Every exterior piece contributes to handling via aerodynamics
  • Rear wing adds an “amazing” amount of down force
  • Side slats contribute to side force… very helpful for high-speed corners


  • Cooling is one of the biggest challenges
  • Rear-mount radiator for space and to avoid damage; most efficient PWR radiators available, same used as Formula 1
  • Wheel controls help fine-tune details like how much wheel spin they get at starting line
  • On-board computer shows all vehicle stats
  • Shift lights to help prevent short-shifting due to extreme engine power

Engine, steering, chassis, exhaust, etc.:

  • 35º engine angle, rolled back
  • Engine: 2 liter (.53 gal), 50 lbs of boost, 1,000 hp (before turbo)
  • 45 mm (1.77″) air restrictor on turbo
  • Penske helped develop custom shock absorbers (a new partnership)
  • 17″ wheels
  • ENEOS Gear Oil (up to 76 shifts in one lap)
  • The hand brake disconnects the front from rear wheels and activates a rear brake to help change directions quickly
  • Exhaust system completely built out of inconel; Manifolds and “lots of other parts” are 3D printed with inconel
  • Front and rear differential are all adjustable (how fast tires lock in together and how much traction they get)

Every part was made custom for rallycross or this specific vehicle.


Watch the video for more amazing details about the Steve Arpin 00 ARX rallycross vehicle.

In case you missed it, catch the other The Hoonigans ENEOS ARX Series videos:

Can Dish Soap Stop a 600hp AWD Rallycross Car from Launching??

Team Hoonigan’s video introduction of Arpin made during the initial race in Austin:

More about Steve Arpin/ARX Partnership