In every form of racing certain machines set themselves apart from the rest of their class, and we recently came across one particular Polaris RZR 4 which does just that. As the western regional sales manager for Polaris, Matt Parks had the opportunity to test the RZR 4 in the vast desert of Southern California before many people were able to get their hands on one. It was during these testing trips that Matt realized how smooth and controllable it was while going at high speeds through the rough desert terrain. After that day in the desert, the wheels in Matt's head started spinning and the blood of a desert racer took over as he pondered how competitive this machine would be in the UTV class of the Best In The Desert racing series. With past racing experience and success aboard the Ranger XP and RZR, Matt was determined to make the ultimate desert-racing side-by-side anyone has ever seen.
Kicking It Off
Knowing you can't just take an ordinary machine off of the showroom floor and race it, Matt had quite a few calls to make, but before he even started dialing he wanted to verify that he could race this machine. His main concern prior to starting this project was to make sure he would be legal because of the length of the RZR 4. As per Best In The Desert rules in the Pro UTV Production Class, you are not allowed to alter the wheelbase of the vehicle and must run the OEM engine in order to be considered legal. Since the RZR 4 was a production model, Parks was given a green light to start his project and his first call was to Mark Holz, who is well known for building some of the most competitive race RZRs to date.
After discussing with Mark what he wanted done, Parks shipped the RZR 4 up to the Holz shop in Lynden, Washington, where it would be stripped down and have the stock suspension replaced by a set of Holz +3 (over standard RZR 4 width) A-arms mated to Walker Evans 2.5-inch race shocks. This suspension combination increased the travel from 12 inches all around to 14 inches in the front and 15 inches in the rear ensuring that Parks would have a smooth ride at any speed. A custom tube roll cage was created, and Holz would change some of the interior to better suit a driver of Matt's size. Standing at 6 feet 2 inches tall, Matt found the standard seating position a bit too cramped, so Holz relocated the seat mounting position by moving it 4 inches back; eliminating the rear seating area allowed this to be done with ease. Holz also repositioned the steering wheel to give Matt more of a NASCAR-style feel and allow him to drive the machine with a more relaxed arm position lower on the steering wheel. Mastercraft 3G seats and five-point seat restraints were installed to ensure the driver and passenger are comfortable and secure for prolonged periods of time in the seats. Aside from opening up more comfort room, the extra space as result of removing the back seat also provided the perfect mounting location for the 12-gallon required fuel cell. Holz made a full set of body panels and roof that give this RZR 4 its sporty look.
As Holz was working on the rolling chassis, Parks thought about options for an engine kit to move his racer through the desert faster than anyone else. Since everyone under the sun makes multi-stage performance kits for this engine package, Matt narrowed down the criteria to meet his needs. He wanted to bump the engine up to 800cc from the stock displacement, generate plenty of usable power all while still being able to run super-unleaded pump gas. The final choice was to run a Kroyer Racing Engines Stage III performance kit. Kroyer is known for building some of the best-performing engines in motorsports from NASCAR to off-road trophy trucks. The kit consists of head porting, oversize valves, camshafts, larger throttle body and performance CDI unit. To ensure the engine had no shortage of fresh air, a canister-style air filter was installed, and a Muzzys dual-exhaust system expelled the gasses of the new powerplant.