What is a prerunner truck and how to build it right?
Prerunner is a truck modified for high-speed off-road racing on rough desert terrain. It is used by professional race drivers to prerun the track course, train and make the test runs.
Let’s find out what is a prerunner truck definition and what is the meaning behind this term. Many off-road magazines, blogs, and listings often speculate with this term and widely use it to describe beefy trucks or SUV modified for off-road racing. There are few elements though that make them stand out from the crowd of other modified rigs such as wide stance, large tires, bulge fenders, long travel suspension, etc. To see the reason for such an outlook let’s take a closer look at the origin of this word and functional requirements of the vehicles used for desert racing.
The word prerunner came to us from the auto sport and desert races such as Baja 1000 in particular.
Unlike many road races like Indy 500, there’s no particular course and vehicles do not run on a track. Checkpoints are often located in the middle of nowhere and racers are up to decide which course to choose to get there faster than competitors.
Interesting fact: Spence Murray was the first winner of the Baja 1000 and he was driving a Rambler American, which was way too far from being the fastest truck in the race. Despite this fact, he actually won the race simply because getting lost in the desert less than all other competitors.
In order to learn the course and find the best way to the checkpoint racers pre run it. Better you know the track – better the chances to win. Depending on the track, pre-running the course usually takes from two to seven days.
As you know, race trucks for such competitions like Baja 1000 or Mint 400 require very serious performance upgrades and therefore cost a lot. Sometimes the cost of such rig exceeds the amount of $1.000.000 and obviously, it wouldn’t be the right thing for a team to use their primary trophy trucks to pre run a course. Race team usually has a couple of other less expensive and less modified tucks to do this job. There are usually 4 people in the team who are involved in prerunning: driver, navigator, team manager, and mechanic, so they often use two trucks (two people in each).
A truck for pre-running must be capable on rough terrain, must have a good amount of suspension travel, hold necessary gear, such as shovels, lift jacks, canisters with fuel or custom tank and a pair of spare tires.
Check out a classic Ford F100 prerunner having fun in Middle Eastern desert:
2WD or 4WD
Many say that prerunners can only be 2WD, but it’s not really a necessity, as both 2WD and 4WD can be easily used for this purpose. 2WD trucks are used more often because of the few factors: the absence of the front axle and transfer case, which results in a lighter weight, better suspension travel, and easier modification/maintenance. 4WD trucks, on the other hand, are more capable on the rough terrain, which means that you have smaller chances to get stuck in the middle of nowhere. Additionally, four-wheel drive trucks run straight and don’t get sideways in a drift like RWD rigs sometimes do.
How to build a prerunner truck?
Truck body style is the most suitable for high speed desert racing, so the most common platforms are Ford Ranger, Chevy Silverado, GMC Sierra, Toyota Tundra, Nissan Titan prerunner etc. SUVs are less popular however the most common models are Jeep Cherokee, Ford Explorer and Chevy Tahoe prerunners.
It’s obviously one of the most important modifications that are done to a vehicle in order to run over extreme desert terrain. Occasional hills, rocks, and other obstacles are very dangerous for a truck cruising at a high speed, so the wheels must be large enough to drive over and not get damaged.
Prerunners typically use 35″ – 37″ and larger tires, however on some smaller pickups like Ranger or Tacoma you can sometimes meet 33″ – 35″ tires.
Suspension and Shocks
To ensure safe cushioning and to absorb all the bumps that are met by large tires on high speed – it’s required to have a long travel suspension with extended shocks and bypass. The height of a bump, hole or an obstacle that can be safely rolled over, directly depends on the suspension travel length. Professional trophy truck may have about 30″ of travel to run on the racecourse, other pre-runner pickup trucks may feature other length but it’s typically not less than 12″, however it may slightly vary, especially on smaller trucks.
Wider stance is also required for advanced stability and handling.
Prerunner fenders and quarterpannels
Large tires and suspension kit will not fit under the stock fenders directly, so oversized bulge fender kits are widely used by professionals and enthusiasts. They are usually made of fiberglass or other automotive plastic like ABS or polyurethane and installed both on the front and the back. Front fenders are often incorporated with the hood for easier access to the engine compartment. Rear prerunner quarter pannels are also used to ensure normal clearance on the back.
Skid plates and Bumpers
As well as the fenders, stock bumpers will surely interfere with oversized tires and skid plates, so they are often swapped with beefy off-road bumpers. Tubular off-road bumpers are widely used because of the lightweight, lower profile and ease of fabrication. Winch bumpers are also used on prerunner. Rear bumpers are often tubular for better weight balance.
Engine power plays a key role in a prerunner build because the truck must be capable to haul its own weight which is way off being light over the rough terrain at the high speeds of about 90MPH. The majority of the rigs runs on V8 gas engines, however, diesel is sometimes picked as an alternative. Typical power adders are superchargers, turbo, and twin-turbochargers paired with performance transmission, air intakes and exhaust systems. Cooling systems and A/C also play an important role.
Prerunner exhaust system is often straight pipe and features headers, downpipe, side swept or rear exist dual mufflers and resonators.
Desert races are very dangerous because of the unpredictable terrain and high speeds, so every team takes care of proper safety measures. Rollcage is often installed on soft bushings and protects the driver from rollovers and other hazards.
Seats & Harness
Proper sport bucket seats and multipoint harness will definitely do a better jub in holding your butt on extreme turns and jumps, than a stock bench seats, So don’t even think to skip this checkpoint.
Overall prerunner truck interior looks very spartan, and a dash is often modified to fit various Gages, tumblers, buttons, and monitors.
Spare tire carrier
Running wild in the desert without a spare tire can easily leave you stranded in the middle of nowhere, and the chances for a flat tire are very high here. Keeping in mind that average prerunner wheels are pretty big and heavy, you got to think about a modified spare tire holder.
Most of the prerunners use a for either one or two full size tires. They must be convenient enough to be able to take aspare from the holder and put a bad tire back on. Lift jacks are often used.
High capacity fuel tank
Stock engines are often being modified with various performance components and superchargers and turbochargers which is directly influences the gas mileage, which is far from average in a sport mode. Additionally the distance between checkpoints may be to big and obviously there are no gas stations in the middle of a desert. That’s why high capacity fuel tanks are often used, to keep the team on the go.
Another highly important device in the desert is a GPS navigator, that will always show you the right way out and keep you following the course, because it’s very easy to get lost, especially if there are no roads.
Driving in the twilights or in the dark is always dangerous as the driver may not be able to notice large obstacles at the high speed, and the headlights are not enough to properly light up the road in front of a truck. Modern high mount offroad lights and LED light bars provide enough light to do this job, plus they improve the visibility of your truck, so it could be noticed from a long distance.