One of the many things we've learned from testing and riding in the dunes is that you had better have your ducks in a row before heading to the sand. The massive loads sand riding puts on your motor will only exacerbate any weakness in your engine's performance or setup. A perfect example of this was when our long-term Polaris Predator was out in the dunes. Many of our test riders were frustrated by the modest low- and mid-rpm output from the 500cc mill.
Looking to correct this, we racked our brains, thinking about potential hop-ups to make the Predator a more-feared duner so that we could hold our heads high on the beach (or in the dez). The Polaris packs a stout punch but is decidedly lacking in higher-performance components, especially compared with either of its most-likely dune nemeses-the Yamaha and Honda 450s. Luckily, the folks at BoonDocker understand that enough isn't always enough; they manufacture a line of nitrous-oxide injection systems for the power-hungry rider looking to supplement his or her diet.
Nitrous oxide? Laughing gas? It'll blow up your motor, it's a hassle to use and it doesn't last, right? Wrong! There are a lot of misconceptions about nitrous-oxide injection-some true, some based in reality and some completely false. Nitrous oxide is a gas stored under very high pressure (as is helium and nitrogen) that, when injected into your intake tract, provides extra oxygen for combustion. More oxygen means more power, if you can supply more fuel to burn with the added oxygen.
The innovative part of the BoonDocker system is how it meets the demand for additional fuel. Normally, nitrous-oxide injection is rather complicated, involving the development and installation of a secondary fuel system. Instead of requiring the plumbing of a second fuel line and the wiring up of a fuel pump and all the required solenoids, triggers and such, the BoonDocker kit uses a proportional bleed to divert pressure from the nitrous tank to supercharge the float bowl, forcing additional fuel past the main jet. To ensure the float bowl is pressurized, the carb vents are fitted with plugs that have minute holes drilled in them. Sounds neat, right? It's a clever way to simplify what is typically a fairly complex system, which made us a little nervous, because if the BoonDocker crew didn't do their homework, we were going to be the ones sitting on top of the mess.
Before we installed its nitrous system, we followed the company's advice and junked the stock exhaust. Why cork up all the potential fury of our motor with a stock pipe? We installed and jetted our quad to run with a Pure Polaris slip-on exhaust canister (manufactured by White Brothers for the Minnesotans). Just in case we were still constipating our angry beast, we placed a call to White Brothers and ordered a spare pack of E-Series diffuser discs so we could experiment with varying the back pressure during our dyno testing.
While not as easy as bolting on an exhaust system or a high-flow intake filter, the BoonDocker system was fairly straightforward and was well-detailed in the instruction sheet. If you know your way around a wrench and take your time, you shouldn't have any problems with the installation. If you're not feeling confident in your abilities, this isn't the kit we'd recommend to cut your teeth on, as a decent understanding of mechanical workings is necessary. Particularly, the placement of the components for the nitrous manifold is quite important, and since you are drilling holes in your airbox, you get only one shot at it. We had to bump our main jet to a 160 (from a stock 150) to get the machine to run properly again because of the slight vacuum created in the float bowl when the nitrous is not engaged.