HPI BAJA 5B

Before we start lets clear one thing up, this kit is called a Baja and pronounced Bar-ha, not like a pile of fried onions down your local Indian or even like a nocturnal furry black and white animal. Now we have that sorted. For years people have tried to convince me that large scale petrol powered kits are the way forward, and while I've always appreciated they have a lot of things going for them, none have ever really appealed to me. That is until I first caught sight of the new Baja 5b from HPI, nearly nine months later and I'm stood on top of a 40 foot high sand dune busting the Baja up a 30 degree incline while it kicks out sandy rooster tails several feet high and thinking perhaps all those people were right!

The post-mortem

The Baja is certainly very distinctive in its looks, in fact I think it bears a closer resemblance to its full size equivalent than most other scale off-road RC kits around today, and that's because the design of the Baja 5b has been taken from the desert buggies found ripping up the Baja desert in Mexico, the very place HPI USA launched this kit to the American hobby magazines (I'm told our invite and plane tickets got lost). Still, back to getting this sand out and the first thing I pull off are the wheels. They bolt onto 24mm hex stub axles and the nuts themselves are grooved on the inside and bite into the wheel to give a very tight fitting, so tight in fact that the plastic wrench included with the kit soon starts to suffer. The whole wheel mounting system is unique to the Baja and therefore different to other large scale kits so you can't use any of their wheels and tyres on it, unless someone makes an adaptor that is. The Dirt Buster tyres are what you would expect to see on a tenth scale 2WD buggy, just a lot bigger. They're also conical shaped, meaning there's more side wall on the tyre on the outside than the inside and they mount on the wheels with a bead lock system. This is a ring fixed to the wheel with ten screws, clamping the tyre in-between and removing the need to glue any tyres on! The manual does advise that the rear ones will wear very quickly if you run on tarmac and the word from the people that didn't believe them and tried confirms that indeed they do! Personally I did about four high speed runs on tarmac with some sharp hand brakes at the end and mine look no worse off, I just wouldn't advise a lap around Silverstone with it. The next thing to come off is the body shell, or what there is of it. Remarkably the retail price on a new one is £75, so look after it. There're three parts to the shell and only the main bit in the middle needs to come off for most maintenance tasks. The lower part of the side wings are attached to the plastic skid plate which protects the rear of the chassis underneath. Learn from my mistake here though and remove the headlights attached to the roll bar (by body clips), if you repeatedly flex it round these the shell will break. All the parts of the shell are held on by body clips which as I was soon to find out, is how a vast majority of this truck is held together, making it very easy to get the different components in and out.

Guts and Glory

With the shell off, the internals are at last exposed although typically for HPI everything inside looks very nicely packaged and sealed in. At the heart of the buggy and easily noticeable from the outside is the 4mm thick aluminium tubular ladder chassis, which is of course anodised in HPI's traditional purple. This forms the backbone of the buggy which everything, including the rear end, attaches to. Stripping it down to this is very easy thanks to the aforementioned body clips that hold the roll bar, radio equipment box, fuel tank and air filter and with these removed, you can easily get into the chassis to clean it up. The roll bar needs to come off before you can get to the radio tray which houses the servos, receiver and a 2000mAh rechargeable battery pack. The steering servo pumps out an impressive 25KGs/cm and is water resistant, as is the throttle and brake servo. This I can vouch for having run through many a rock pool and across the wet sand when the tide went out! Increasing the water resistance is the rubber sealed on/off switch located underneath the radio box and accessible through the shell when it's in place. Sitting behind the radio tray is the fuel tank which is perfectly moulded to fit into the centre of the chassis and accommodate the fuel lines and air filter on top of it.

The Baja being an RTR comes equipped with a 27MHz FM transmitter and receiver, the important bit here being the FM. Even I latched onto the fact that large scale petrol powered models create a lot more RF noise which interfere with the normal AM frequency. The standard equipment all worked well and even has a built in failsafe which kicked in several times when the battery lost power, annoyingly the battery didn’t last as long as a tank of fuel on the first few runs.

Horsepower

With all the guts removed, the shear size of the 23cc petrol powered Fuelie engine is fully revealed and running a conventional two stoke engine which is more commonly seen in a hedge trimmer, is what makes a large scale kit so different. They aren’t prone to anywhere near the amount of hassles you get with a nitro engine, have a standard spark plug and pull start that generally fire the engine into life on it’s first or second pull. It will also sit there and tick over all day long, doesn’t require as much tuning and when you need fuel, you just pop down the petrol station! It does of course require some two stroke oil to be mixed in with the fuel and HPI kindly provide you with some to get yourself going, you’ll only get two tanks out of this though so get some oil in ready, I’ve been advised by those running large scale kits a lot longer than me that the quality of this oil makes a big difference and something like Castrol A747 is a top recommendation, although I bought some and can’t really feel a lot of difference! While a 23cc engine might sound massive, in the world of large scale kits it’s actually quite small with most other makes coming with 26 or 29cc engines. The good news is the Fuelie engine in the Baja is a re-badged CY engine so you can slap one of their big bore kits straight in, and of course I expect HPI will bring out a new high powered version within the next year if this kit proves to be a success. The engine sits across the chassis, so on one side you have the pull start which has vents all round the casing and fins inside so when spinning it creates an air flow to cool the engine. I had to open this up out of necessity as the only thing to go wrong in my first run on the beach was the pull start failing to grab onto the engine. This proved to be more of a case of it being full up with sand than broken so with a quick blast of air inside it was working perfectly again.