4 doritos in a dinghy

A while back I did a spotlight post on a very special boat that is circulating around ponds here in New Zealand, although this one breaks the mold.  Jet sprinting originated in NZ, and is dominated by V8-powered boats.  So when Peter Huijs showed up back in the day with boat that sounded slightly different, we all sat up and took notice.

Jetsprinting in a nutshell, is a jetboat with a crew consisting of a driver and a navigator racing against the clock through a twisting series of channels in 70-100cm of water. Each run usually takes around 55 seconds, and consists of 25-30 changes in direction, and as far as spectator sports go this one is hard to top!

Click on photos for larger version

So what exactly is it that has everyone on the internet talking about this boat in particular? Well for starters the traditional V8 has been done away with in favour of this…

Warren Overton of Pulse Performance Race Engineering worked his magic on this quad-rotor engine setup, and boy does it sound good!

MAD AZ runs a side port quad-rotor powerplant with a Garrett GTX 57 turbine spitting out roughly 1300 horsepower.  With jetsprinting producing high G forces, the engine needed to be drysumped.  Warren was also very aware that this would have to be one tough engine due to the boat being on wide open full boost throttle for up to a full minute on some courses.

The office isn’t a spacious one, you have a couple of bucketseats where driver and navigator are slung nice and low, held firmly in by a 5-point harness. The harness of course keeps the crew tightly in place, and they certainly need it as these boats produce 7g’s when cornering.

With everything happening in a split second during your run, you don’t have any time for ‘fine tuning’ so the approach to the cockpit is nice and simplistic. You have a steering wheel complete with one of those ‘mysterious little red buttons’, which in this case winds up your boost for the short moments you happen to be going in a straight line.  Also in this cockpit you will only find one pedal – the loud one.

Of course these drivers only know one way to drive – flat out. Well they have no other choice really, because if you lift off the loud pedal you basically loose steering…

This is because the power is delivered by a jet unit, it’s like having the worlds most powerful vacuum cleaner attached to your boat. To keep things moving and most importantly, turning, you need to keep your foot down. Suck the water in from underneath and squirt it out the nozzle to go.

And go it does! These jet units pump 2800 litres of water a minute which is good enough for 0-160kph in under 2 seconds…

Of course with no rudder for turning, you once again rely on the jet unit squirting water for turning the boat also, of course it wouldn’t be kiwi if there wasn’t some good ol’ wire and pulleys to assist you…

Also these boats are direct-drive : no gears, and they only drink the good stuff – Methanol.  Warren tells me that one huge advantage of running this engine in a boat vs a car is that you have unlimited cool water.  Producing the amount of horsepower that this boat does, you get an enormous amount of heat.  Warren has developed an automated cooling system that regulates the engine coolant temperature introducing cool fresh water from the jet unit when required.  This is what Warren sees as the real key to the reliability of the quad-rotor.

The air is full of the throaty burble of the big V8 boats, when all of a sudden the unmistakeable ‘brap brap’ of the rotary sings out as the quad-rotor comes to life.

In the blink of an eye these guys go from sitting in the water to top speed, if you want something challenging to shoot as a photographer, this is certainly it!

The most impressive aspect of these boats is their cornering ability. The hulls are 23-25 degrees with several strakes for traction in the water. At these speeds inch-perfect precision is needed if you plan on keeping your boat on course.

Just like in any other motorsport, the boats are able to be set up according to the track. Propellors with differing amounts of pitch on the blades can be changed to suit the track you are running at.  The lower the pitch, the better your hole-shot. However, this comes at a price: top speed.

The sport is very ‘quick-fire’ and with sub-one minute runs from each crew, before you know it you are back in the water ready for another run.

One of the most amazing things about the sport is that the driver is not ‘told’ where to turn, the navigator uses hand gestures to show the driver where he is going. Driving one of these boats and watching the hand of your navigator for direction, now that’s talent.

Peter and Garry with the help of Warren have certainly created something awesome, it is the first rotary-powered sprintboat in the world that is used in competition, and this is one of the few boats that doesn’t need to worry about burning out it’s starter motor in the loading pool too!

This particular shot was taken in what is known as the ‘spinout pool’. Drivers go through the flying finish at 160kph and about 25-30 metres in front is a big circular pool in which they throw the boat into a 180 degree turn to come to a stop. 160-0kph in less than 2 seconds as well…now that is impressive stopping ability…without ‘brakes’ too!

So how do they go about finding a winner? Well every crew has 3 qualifying runs which lead to sudden death.  From there you have a top 16, down to top 8, top 4, and top 2, which leaves your with your podium placings.  It’s great too, as often the top 4 boats are scrapping it out and can be separated by less than a second.  Tension in the boats and the grandstands is certainly fever pitch.

It’s awesome to see in a sport dominated by one engine type, something different, this quad-rotor machine is certainly a brap of fresh air. It is great that Peter & Garry, with the help of Warren, decided to go with something ‘out of the box’, in fact it is so revolutionary in this sport, that I am pretty sure they were unaware a ‘box’ even existed in the first place. Good on ya guys!

Now we all know photos don’t do some things justice so sit back, turn up those speakers and enjoy the noise that is the quad-rotor jetsprint boat! Big thanks to Neil Jones for the footage.

Qual 3 Rd3 Waitara

Posted by Neil Jones on Saturday, February 25, 2017


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