Off-road race teams typically use a vehicle other than their race car to pre-run racecourses prior to a specific event. This gives them a chance to see the course for the first time and make GPS notes of danger areas and pit-stop locations all without putting extra miles on the race car. Some teams spend anywhere from $50,000 to $500,000 on these vehicles. Many of these machines are long-wheelbase buggies or trucks and have three seats, so all occupants have a clear view out of the windshield.
Building a pre-runner with that kind of budget is something we don’t have the luxury of doing. However, we do think the Polaris RZR 4 can be used to accomplish the same task for a significantly smaller investment. We took our 2015 RZR 4 and spent the year building and perfecting a great pre-runner. We used it to prerun the Parker 425, Baja 500, Baja 1000 and every round of the Pure UTV Series (www.averacing.com) in California City, California.
After our first trip of the year with the machine in stock condition, we went to work, and our focus was on suspension, durability and communication. We needed better tires, spare tires, better suspension, radio communication, storage and much more.
FROM THE GROUND UP
The hottest tire size going for larger UTVs like this one is 30X10-14, and they fit the project perfectly. Having a slightly taller-than-stock tire helps with ground clearance while not hurting gearing or requiring any clutch changes.
For this project we went with ITP’s eight-ply Ultracross R Spec tire. It’s proved to be strong and helped us win the Pure UTV Series championship in 2014. We mounted the tires on ITP’s T-9 spun aluminum wheel equipped with beadlocks. The spun wheel is lightweight, has a slightly wider offset and is much easier to repair than a cast-aluminum wheel.
You see, when you are pre-running, you could be in remote places hundreds of miles from the truck. If you happen to get a wheel failure from a rock getting wedged between the brake caliper and the wheel, the spun wheel can be welded or even hammered back into place and a tube could be used. The spun wheel is a little softer and should actually bend instead of break. We did carry a spare, too, that was mounted on an Assault Industries tire carrier. This carrier mounts on the rear cross bar of the RZR’s roll cage and holds the wheel into place with supplied hardware. We positioned the tire upright on the left side of the bed so it didn’t block the view of the driver looking into the rear-view mirror.
The huge convex rear-view mirror ($84) and the two red matching RZR side mirrors ($239) were also from Assault. They clamp right onto the 1 3/4-inch roll cage and give a great view of things behind you. Even though the RZR is a very capable offroad machine, some of the high-dollar pre-runners out there can carry double the speeds of the RZR, so keeping one eye on what is behind you is important. Assault has a ton of other accessories for all UTVs, including seat belts, roofs and fire extinguishers.
Although we did use the stock seats and doors, we did want to surround the occupants a little better. We used Pro Armor door halves ($299 a pair) on all four doors to keep debris and sand out of the riders’ laps. They bolt on easy to stock doors and dress up nice with color-coated, OEM-looking graphics for another $129. Pro Armor sewn-together four-point harnesses kept the three passengers firmly in their seats for $109 each.
The most unique modification this project offers is the center rear seat. We had Master Fabrication in California build us a framework that would not only allow us to bolt one middle seat into the rear section of the car, but it could easily transform back to a four-seater. So, the framework clicks right into the stock seat location using the stock hardware. In seconds, you can remove the center seat and click two rear passenger seats back into place. If needed, you can retain the stock seat belts for the four-passenger configuration, or you can install two harnesses in the back and just use half of each harness when in the three-seat mode.
The center seat base also has tiedown hooks for securing things like coolers and toolboxes. In our cabin, we used an Ogio street bike tank bag to carry a spare secondary clutch, ball joints and a few other parts. Next to that we used a piece of 3-inch PVC tubing cut to length to hold a spare axle and CV assembly. On the opposite side, we used a Quadboss can beverage holder to carry a pair of radius rods. To cap off the driver and passenger compartment, Master Fabrication constructed a mild steel roll cage with front anti-intrusion bars, wider center downtubes and a pair of harness bars. The top of the cage had a clean, slim aluminum roof and sun visor along the full length. The cost of the cage was just over $2000.
If you have ever ridden in the back of a four-seat UTV, it’s not exactly the best seat in the house. While the front seats feel smooth and you have a clear view out front, the opposite is true in the rear. Typically, the suspension bottoms out in the back earlier than the front, and there is just more movement back there. Also, the view in most four-seaters is horrible, unless you like looking at the back of the driver’s seat or a helmet. We wanted to address both of the issues, so that’s why we moved the back seat into the center. It gives a great view out front.
To take care of the shock issues, we turned to SDI suspension. These guys have been building performance shocks for short-course race UTVs for years, as well as dirt bike suspension. We told SDI what kind of weight would be riding out back with spares and the single passenger, and they went to work.
What they came up with was a rear suspension package that was not only more adjustable than stock, but it was much stronger. The entire car now sits a little high initially instead of squatting. This way, nearly half of the suspension travel is in reserve and ready to take up that first bump. Most of the pre-running this year was done with our test driver sitting in that rear seat. As it turns out, the rear seat ended up being the most comfortable place to be. The placement actually allowed for more legroom too.
The SDI shocks in the rear received new high/low-speed compression adjusters, threaded crossover rings and heavier springs. This way we could make adjustments on the fly and get them tuned to suit the comfort of the rear passenger well. At the front end SDI added the threaded crossover rings, as well as their specific valving. The spring rate was left stock.
Overall, the rear shocks ended up working better than the front. We had to play with spring preload a bunch and ended up liking their softest setting for the speeds we were hitting. To finish off things at the rear end, we installed a set of Assault Industries high-clearance radius rods. They are adjustable and add to ground clearance out back. SDI has quality tie-rods and radius rods too; we just wanted the high-clearance products, which they don’t make yet.
To make the pre-running days more productive, we installed a Polaris branded Lowrance GPS on the front passenger grab handle of the RZR. Installation was clean and vibration-free, thanks to a $40 ModQuad passenger grab handle, anti-vibe clamp and a trick $90 billet-aluminum GPS mount from Mechanical Concepts. Our dedicated navigators used it to mark pit-stop locations, where to go fast and where to watch out. Proper use of a GPS can take minutes off your overall times, as well as keep you from getting lost.
Also in the cabin, we equipped every door with a Pro Armor kneepad pocket set. Each $100 set has one kneepad and one zippered pocket to hold items like toilet paper, flashlights, tape, zip-ties and tire plugs. If we do have to repair a tire on the trail, it can be easily aired up using a $159 20-ounce Power Tank CO2 bottle called the Power Shot Trigger System. Each full bottle can fill up a 30-inch tire about 10 times to 10 psi. Fill-up time is about 5 seconds. The bottle, as well as two Assault Industries fire extinguishers, is attached to the rear roll cage with quick-release mounts.
During the course of pre-running, it’s imperative to discuss the terrain between the driver and passengers. They need to talk over line choices, speeds to hit certain sections and things to mark on the GPS. So to do this, we installed a complete communications setup from Rugged Radios. To link all passengers together, we installed a $909 RRP660 four-place intercom kit. With each of our $540 Arai XD4 helmets wired with speakers and a microphone, we could have crystal-clear conversations all day. This helmet has a large 3/4-inch gap between the top of the helmet and visor, so the visor doesn’t catch a lot of wind. The intercom system is an open-mic setup or can be set to voice-activated, so all you have to do is talk; there are no buttons to push. Each helmet had a separate $99 helmet kit that includes two speakers and one microphone attached with Velcro and a hot glue gun. To keep in contact with our chase truck, we paired a Vertex 2200, 50-watt VHF radio with the intercom box. Both units install neatly on the lower portion of the RZR’s dash using Rugged’s convenient thin dash mount for an extra $45. Many say that pre-running an offroad race is more fun than the actual race. It’s definitely a lot cheaper, that’s for sure. If you take your time to see the sights and build a pre-runner with features like this, you will be guaranteed to finish the course and still have a machine that’s in good shape to drive the very next weekend.
Assault Industries: (714) 799-6711, www.assaultind.com
Lowrance: (800) 628-4487, www.lowrance.com
ITP Tires: (909) 390-1905, www.itptires.com
Master Fabrication: (310) 880-1221, www.masterfabrication.com
Pro Armor: (951) 343.9270, www.proarmor.com
ModQuad: (541) 791-2887, www.modquad.com
Mechanical Concepts: (707) 267-7911, www.mec-con.com
Power Tank: (209) 366-2163, www.powertank.com
Rugged Radios: (888) 541-7223, www.ruggedradios.com
SDI: (714) 464-2050, www.suspensiondirect.com