Trucks to eat up toughest terrain

Dan Cowper uses Chevrolet engines in his trucks, the biggest of which pushes out 600 horses. Picture/Stuart Munro

There are beasts lurking in Dan Cowper's shed.

Weighing 1250kg and ranging between 300hp and 600hp, his latest custom built four-wheel-drive competition trucks look like they are ready to eat any terrain thrown at them.

Cowper's business, Cowper Trucks, has built 16 competition trucks which have performed at the highest level in New Zealand's fiercely contested four-wheel-drive trials scene and right now he has four more under way in varying stages of completion.

Each truck costs about $100,000 which sounds pricey but owners end up with a hand-built machine for just one purpose - getting over terrain that almost nothing else can.

Cowper, 40, is married to Karen and has two kids, and apart from a stint overseas has not strayed far from his home village of Turakina.

He has won four national four-wheel-drive titles himself and, along with fellow four-wheel-drive competitor Phil Shailer, builds trucks other competitors want.

"My customers are those usually already in the 4x4 trials scene that want to make the step up to the top of the field and compete for national titles."

Cowper said he had been lucky enough to turn his hobby into a business and had been building trucks full-time since 2001.

"I always wonder if the work is going to dry up but it never seems to."

At the moment, he is simultaneously building three competition trucks and has a custom beast based on an American Jeep waiting in the wings.

Cowper completely builds the chassis and frame work and hydraulic rams for the power steering as well as seriously customises the differential set-up.

"They start out over there (a steel rack) and end up being driven out of here."

His trucks are based on Chevrolet motors and use the LS series, which are included in Commodores, Camaros and Corvettes.

The three competition trucks being worked on at the moment are powered by and ranked by horsepower, an LS1, LS2 and LS7. The LS7 is a hulking seven litre V8 which produces 600hp.

Each wheel has an individual brake operated by the co-driver and four-wheel steer is also an option for some trucks.

One of Cowper's most innovative touches is reducing the wheel base by heavily modifying the transmission required.

He takes the front wheel drive transmission out of a Toyota Windom car and attaches it to the rear of the engine.

Then he alters the output shafts, which previously would have driven the Windom's front wheels, so one drives the rear diff and one drives the front.

This lessens the room needed as compared to a traditional four-wheel-drive gear box, reduction box and transfer case.

The only problem with using these transmissions is the competition V8s chew them up and spit them out.

"The hardest thing was finding a car transmission that could handle the horsepower. The owners realise that they will have to replace these boxes every year or so."