Custom build: Isuzu D-MAX X-Terrain 6x4

Super-specced D-MAX clears the boundary when it’s time to up stumps and head on out

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You see it more often than not on the holiday trail. Dual cabs with overloaded canopies, or swaying wagons loaded to the gunwales, stressing the chassis and suspension well past any reasonable GVM limit.

We all know there’s only so much four wheels can take, given all that extra load needs to be supported by the often overlooked axle bearings doing their best not to explode on some remote track between paradise and the parts store.

In the case of the 2021 D-MAX you see here, Callum and Nicole McDevitt have plans to do some serious extended touring, but with daughter Mackenzie also in tow they wanted to make it a little more comfortable than a swag, fridge and gas stove.

This, of course, was going to level up their tonnage, so they chose to acknowledge the elephant in the room by realising a simple spring and shock upgrade wasn’t going to achieve what they had in store, especially when towing a fully loaded caravan nudging nearly four tonnes. Not only that, but it was all going to require a little more mumbo to shift it too.

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After punting around in a 2015 D-MAX LS-U both Callum and Nicole were pretty happy with the Isuzu product, but weren’t completely set on just grabbing the newest model again.

They spent time looking through the usual long-haul options, which included LandCruisers, American trucks, and even a bigger upscale to a light truck, but in the end the features and looks of the newer D-MAX in X-Terrain trim had them frothing for one in a Volcanic Amber hue. They just needed to make a few adjustments before they set off on tour.

“We wanted it to be capable of touring around Aus, taking on the odd track or two, beach four-wheel driving and being able to sustain a couple of weeks off-grid,” said Callum. “To be able to unhook the van and go more remote with the car but still be comfortable and self-sufficient if needed.”

The Gibb Challenge

Hard to miss and mounted on its own pull-out tray is the full-sized Breville Oracle Touch coffee machine. It would be easy to think there might have been some over-indulgence with such a top-of-the-line bit of kit in a 4x4, but there was method to the madness.

“It started as a little side hustle idea,” the McDevitts tell us. “Make a dozen coffees or so for fellow travellers, and maybe offset the cost of fuel as we travel.

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“Since having our car on display at Perth 4WD & Adventure Show and Core Off-Road’s grand opening of their new showroom, we have been asked to tag along with the Gibbsters in May, making coffee for all involved in the mornings and evenings.

“The Gibb Challenge is an annual charity bike ride from Derby to El Questro to raise money for the Royal Flying Doctor Service. When Simon Rimmer (event director) reached out to us, we jumped at the opportunity to be part of such a fantastic event for such a worthy cause.

We are currently shortlisting a few charity organisations, one of which we will partner with and donate a percentage of our coffee sales and online merchandise full-time as we travel Australia,” they said.

Six Wheeler Conversions

Ben and Julian at Six Wheeler Conversions (SWC) in Toowoomba, Queensland, soon had the new D-MAX on their hoist, with a third undriven axle mounted under the chassis. “(They were) so knowledgeable and helpful,” the McDevitts told 4X4 Australia. “The absolute foundation of this build! Absolute legends!”

Given a suspension lift isn’t easily done once the conversion is welded in, Callum and Nicole chose to have it set-up with a two-inch lift, matched at the front by a Formula two-inch upgrade to keep things level.

Adding an extra axle retains 60 per cent of the vehicle’s rear weight over the rear drive axle, which is left in the OEM position. The additional lazy axle helping to support the weight of the extended canopy and extra tow-ball weight from the caravan soon heading its way.

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While the guys were able to handle the conversion with little fuss, getting it certified stalled its completion considerably.

“Our car was one of the first new D-MAXes off the line to have a conversion done, and SWC were waiting for a new SSM licence for the conversions and Canberra were in lockdown, so we waited and waited,” said the McDevitts.

With six-wheel braking also included, the GVM was raised to a sizeable 4630kg, with 4500kg towable. All up, a whopping GCM of 8130kg is able to be legally driven on Australian roads.

CORE Off-Road canopy

With the chassis now able to accommodate a much longer and heavier load, the newly converted D-MAX was turned over to the guys at CORE Off-Road in Rockingham, WA, who made room in their workshop to design their first dual-axle supported canopy.

“Without a doubt they turned our dream into a reality,” Callum said. “A special mention also to Paul who was a massive help and looked after the majority of our build.”

Given a clean slate but a list of needs and wants from Callum and Nicole, the design team fired up the computers and came up with a completely new design for their composite-based canopies. The Phoenix GT-U bears a list of features as long as your arm, but keeps everything easily accessible, as well as easily cleaned, while living life on the road.

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Starting on the passenger side, there’s a 110L Dometic upright fridge sandwiched between the front bulkhead and the electrical control panel, the latter being filled with custom labelled breakers for all on-board accessories.

For outback tunes, there’s a Fusion stereo controller with speakers up in the canopy doors. An Enerdrive ePro Plus auxiliary battery monitor and an ePower 2600W Inverter controller round out the panel, with an Enerdrive 200Ah lithium battery and its 40amp DC2DC battery charger tucked away out of sight.

A Topargee counter keeps an eye on the water drawn from two 80L tanks, with the rest of the panel filled to capacity with various switches for lighting, rear-mounted water pump and high-amp USB-3 ports.

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Swinging around to the rear inner bulkhead of the canopy you’ll find a huge slide-out pantry/kitchen, with drop-down shelves front and rear. The thickness of this assembly easily allows a Travel Buddy oven to be top-mounted and recessed, with a full-length slide-out cutlery drawer emerging from between the bottom rollers.

Both sides of the canopy are loaded with under-tray toolboxes, with a full-size trundle drawer complete with gas-lifted 3mm top shelf out back. Directly above are the Core dual wheel holders either side of the top-mounted rear-vision camera, sending a picture to the clip-on display attached to the now redundant rear-view mirror.

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Moving to the driver’s side finds even more touring equipment and storage. While keeping the upper area relatively open for larger items, CORE designed two large lockable drawers to flank the lower edge and match the height of the Dometic CD30 fridge drawer ahead of them. More lighting switches are also available here, with a nine-metre retractable-reel air-hose located above, being fed by an ARB twin-pump compressor.

Hot water is provided by the Smartek Lite gas hot-water system mounted on a swing-out bracket. Core fitted its fixed gas system, which includes the 2kg gas bottle bracket, inside the driver’s side toolbox, before having the installation certified.

Engine mods

Getting the whole show on the road is the venerable Isuzu 4JJ3-TCX 3L. Undoubtedly to the relief of any trailing uphill travellers, the McDevitts have chosen to upgrade the powertrain.

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Adding in a PWR front-mounted intercooler keeps intake temps down, while a Manta Performance three-inch exhaust funnels spent gasses away more efficiently. An MDP transmission valve body has the cogs shifting sweeter under load, while an HPD transmission cooler keeps its lifeblood from cooking.

A Direction Plus Fuel Manager Pre-Filter was chosen to further filter the diesel of contaminants before +30 injectors shoot it into the cylinders. Lastly, Modified Diesel Performance in Port Kennedy installed the Alpha Tech Firestorm ECU which piggybacks off the OEM unit, before tuning the whole shebang to a safe 263hp, with a sizeable 652Nm of twist.

With thanks

“The build needed the perfect balance of capability, functionality and have that wow factor,” says Callum. “I think we got pretty damn close. All the companies that had a part in this build have all combined to allow us to be able to live out our dream and hopefully inspire others to do the same.

“A couple of massive thank yous to Ben and Julian at SWC, Jimmy and Jodes at Core Off-Road, Perth Detailing Centre in Osbourne Park, Modified Diesel Performance, Toxic Tinting in Port Kennedy, and Fatal FX Panel & Paint in Rockingham.”

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Now that the build is complete Callum, Nicole and Mackenzie are on to their final shakedown runs before heading off proper, already documenting their adventures through all main social media platforms, using their @luckycountryadventures moniker.

Check them out, and if you happen to be wherever they are, there’s a good chance there’ll be a great coffee and a chin-wag when you say hi.

Fast facts

Towing mirrors

Keeping towing their caravan legal, a pair of extendable Clearview Compact towing mirrors allow easy vision of what’s happening behind.

Roof rack

Rhino-Rack Pioneer Platform is mounted with a Core custom backbone mounting system, including a 42-inch Stedi light bar, four Stedi mini LED light bars and four side RGB party lights.


A full complement of eight ROH Vapour wheels fitted with Falken Wildpeak AT3W in a 265/70R17 sizing.


A fully loaded kitchen complete with a portable induction cooktop, stand-up fridge, sink, and one hell of a coffee machine.

Rooftop tent

The iKamper 4X 3.0 rooftop tent, complete with iKamper solar kit using two 100W super-thin panels to top up the batteries. The 23Zero 270-degree awning throws a large shaded patch around the vehicle.

Front bar

An Offroad Animal Predator bar with stealth top hoop helps to fend off errant wildlife. It’s also loaded with a Runva 11XP electric winch with synthetic rope, and Dual Stedi ST1K 21-inch stealth-mounted light bars.

Accessories list

Brad Miskiewicz


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