Polaris Regional Sales Manager Matt Parks built this 2010 Polaris RZR 4 to compete in the Best in the Desert racing series. Known as the “Baja Bobsled,” the four-seat RZR combined a stock-wheelbase chassis with Holz Racing Products suspension, a Kroyer Racing Engines Stage III engine and the equipment required for long-distance desert racing.
Parks was already familiar with off-road competition before entering the UTV class. He grew up racing motocross and later became involved in desert racing by pre-running courses and chasing for friends.
From the Polaris Ranger XP to the RZR 4
Parks became interested in UTV racing after seeing Yamaha Rhinos compete in Best in the Desert events during 2005. Believing Polaris offered a strong foundation for a race vehicle, he converted a full-size Ranger XP into a desert racer in early 2006.
That first machine was called the Baja XP. It retained its stock suspension geometry but used Walker Evans Racing shocks and an engine enlarged to approximately 760cc. Parks and his team raced the Ranger during the 2006 and 2007 seasons with impressive results for a relatively stock vehicle.
The Baja XP won its class at the 2007 SCORE Baja 250—the year the race was relocated from San Felipe—and became the first UTV to officially finish a SCORE event.
The next step was a purpose-built race version of the four-seat Polaris RZR. The RZR 4’s longer chassis created a stable platform for high-speed desert terrain while retaining the agility that helped establish the Polaris RZR as one of the most important sport UTV platforms of its era.
Winning Its First Best in the Desert Race
The newly completed RZR 4 made an immediate impact at the Best in the Desert Blue Water Desert Challenge in Parker, Arizona. Parks won the Pro UTV class on both days and earned the overall class victory in the car’s first race.
“This was our first race for the newly built race RANGER RZR 4. The car ran great both days, and it was really fast, particularly in the rough. It was a great weekend and a fantastic outcome.”
—Matt Parks
The RZR 4’s stretched four-seat chassis helped it remain composed across rough desert terrain. Holz Racing Products suspension paired with Walker Evans Racing 2.5-inch shocks delivered 14 inches of front travel and 15 inches at the rear. A Kroyer-built engine and Muzzys exhaust supplied the additional performance needed for desert competition.
Between its professional fabrication, proven components and first-race victory, Parks’ RZR 4 demonstrated how quickly sport UTV desert racing was advancing. The build raised expectations for the 2011 racing season and helped establish the four-seat RZR as a serious competition platform.
Matt Parks Polaris RZR 4 Specifications
- Base vehicle: 2010 Polaris RZR 4
- Wheelbase: Stock
- Width: 66 inches
- Fabrication: Cage, suspension components, body panels, bumpers, skid plate and mounts by Mark Holz of Holz Racing Products
- Engine: Kroyer Racing Engines Stage III, configured to run on premium pump gas
- Exhaust: Muzzys Performance Products
- Wheels: 14-inch Walker Evans Racing beadlocks
- Shocks: Walker Evans Racing 2.5-inch shocks
- Front suspension travel: 14 inches
- Rear suspension travel: 15 inches
- Fuel capacity: 12 gallons
- Seats: MasterCraft 3G
- Harnesses: MasterCraft five-point harnesses
- Tires: Maxxis Bighorn
- Lighting: Baja Designs
- Radio: Icom 50-watt radio
- Navigation: Lowrance 540C GPS
- Communications: PCI intercom
- Fresh-air system: PCI pumper
- Tracking equipment: Iritrack
- Radiator: Stock
- Graphics: Utendorfer Designs
- Brakes: Stock
- CV joints: Stock
- Axles: Summers Brothers
- Drive clutch: Stock
- Driven clutch: Stock
- CVT belt: Stock
- Transmission: Stock high/low/neutral/reverse transmission
- Front Hilliard differential: Stock with Holz billet cage
- Rear differential: Stock
Race Team and Sponsors
Driver: Matt Parks
Co-driver: Bryce Wernsman
Pit crew: The Baja Bobsled Team, including Bill Abshier of Valley Cycle in Bakersfield, Jason Spiess, Todd Douglas and Danny Flowers.
Sponsors: Walker Evans Racing, Holz Racing Products, Maxxis, Kroyer Racing Engines, Muzzys Performance Products, Utendorfer Graphics, Pure Polaris Lubricants and MasterCraft Safety.
Polaris RZR 4 Race Build Photo Gallery
Photo Credits
- Art Eugenio, AEugenioPhoto.com
- Joey DiGiovanni
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