Inside HPD’s Relentless R&D

When it comes to performance upgrades for four-wheel-drive vehicles, particularly in the demanding Australian off-road environment, High Performance Diesel (HPD) says “few names carry the credibility and industry respect that HPD does.”
“From suburban garages to remote expedition trails, HPD has become synonymous with durable, high-performance intercooler and transmission cooler kits,” HPD Owner and Founder, David Mitchell, said.
But what fuels the company’s continued innovation and reliability? The answer lies in its Research and Development (R&D) philosophy, something the company describes as “an obsession with real-world usability, performance, and quality assurance that few manufacturers match.”

Driven by necessity and innovation
HPD says its product development isn’t driven by novelty, it is powered by necessity.
As a leading manufacturer in the 4WD aftermarket industry, the company says it continuously adapts to changing market demands, new vehicle releases, and evolving technologies.
“Nowhere is this more evident than in HPD’s response to the widely reported power derating issue in the 300 Series Toyota LandCruiser,” David explains.
Recognising a gap in the market for an easy-to-install solution, HPD engineered a high-performance heat exchanger to solve the problem caused by an underperforming factory intercooler system.
HPD explains that power drop in the 300 Series occurs most noticeably under sustained load – such as when towing up long gradients.
It states this real-world issue underscored the need for a better cooling solution, and HPD delivered a kit that not only fixed the issue but elevated the overall performance of the vehicle.
“It is this combination of listening to the market and responding with precision-engineered solutions that has solidified HPD’s leadership in the field,” David said.

Every bit with every kit
David says that what sets HPD apart is not just what they build, but how they build it.
“All HPD kits are designed with the end user in mind – typically a 4WD enthusiast working out of a suburban driveway or shed,” David said.
“All our kits are designed on the ground without a hoist. If the average guy doesn’t have a hoist, why should we use ours?” adds Karl Venning, who has led multiple R&D projects at HPD.
Using only basic tools, the design team ensures that each kit can be installed with minimal fuss.
HPD kits come complete with every nut, bolt, washer, and even bonnet scoops and supplied with detailed step-by-step instructions, ensuring these kits are built for DIY confidence while retaining a professional finish.
The emphasis is always on minimal cutting or drilling, utilising existing holes and openings to ensure a factory-look fitment without compromising structural integrity, says HPD.

Nothing left to chance
Reputation is hard-earned and easily lost. HPD says it knows this well, which is why releasing a new product is never taken lightly.
“Every new component is subjected to rigorous scrutiny before it reaches the hands of consumers,” David said.
“When developing intercoolers, for instance, HPD doesn’t just look at the core dimensions or cooling capacity in isolation.
“The engineering team considers how the unit interacts with other vehicle systems – bull bars, winches, transcoolers, and more.”
Each intercooler is designed to outperform OEM specifications while accommodating the range of accessories that are typically fitted to a 4WD.
“One of HPD’s overarching philosophies is doing as much as possible in-house,” David said.
“To achieve this, a large percentage of company profits are reinvested back into the business in the form of employing the latest machinery, equipment and skilled personnel.”
These include five axis CNC machines, brake press robots, vacuum moulding machines as well as several other robotically automated processes. HPD even injection mould their own airbox lid seals.
One of the latest acquisitions was the DMG MORI DMC75 monoBLOCK CNC machine which can accommodate 60 different tools to drastically reduce machine setup time, which reduces production time especially on complex components.

Location, Location, Location
One of the most critical elements of R&D at HPD is the placement of the intercooler itself.
Optimising airflow is not simply a matter of location – it involves meticulous planning.
Shrouding, ducting, electric fans, and bonnet scoops are all considered and implemented as needed to deliver peak cooling performance.
Importantly, the mounting of intercoolers is designed around existing holes and openings in the vehicle’s chassis.
Stainless steel lasercut brackets and machined billet brackets are employed to ensure strength and longevity while eliminating or significantly reducing the need for invasive modifications.
This kind of intelligent engineering not only simplifies installation but also preserves vehicle warranty and resale value, says HPD.

Rigorous testing protocols
Product development doesn’t end when the prototype is built – it only truly begins.
HPD explains that it engages in a two-pronged testing approach: real-world road testing and dyno analysis. Both are designed to push components to their limits.
During road testing, vehicles tow a standardised 2.5-tonne trailer, which consists of two cubic-meter tubs filled with sand.
These test loops include urban environments, highways, and steep climbs to create conditions that mirror the toughest demands a 4WD could face.
In tandem, HPD conducts exhaustive dynamometer testing to simulate extreme heat loads, airflow rates, and mechanical stress.
All data is recorded both with and without HPD’s intercoolers or transcoolers fitted, enabling clear, quantifiable performance metrics.
“Take, for instance, the Next Gen V6 Ranger. With HPD’s upgraded intercooler featuring a 600x300x76mm core, intake temperatures dropped by as much as 130°C from hot to cold side, compared to just 55°C with the stock intercooler,” Karl explains.
“Transcoolers also showed impressive figures, with 300x200x50mm cores reducing fluid temperatures by an average of 20°C.
“In some cases, road testing revealed inlet/outlet differentials as high as 69.5°C. Transcooler units are also tested in a wind tunnel with thermal imaging to design the ideal configuration.”

Continuous improvement, not complacency
“Innovation at HPD is never a one-time event, it is an ongoing cycle,” David says.
“Vehicles evolve throughout their life cycles, with manufacturers introducing new technologies and hardware revisions often without notice. These seemingly minor updates can throw a wrench into aftermarket compatibility.”
“Car manufacturers like to test us!” laughs Rob Varga, HPD’s Head of Sales.
“They often make running changes and introduce new tech during a model’s lifecycle. Manufacturers call it an update. Mechanics call it extra complication.”
In such cases, HPD says it doesn’t shy away. The team reassesses the existing kits, adapting them as necessary.
Sometimes a few tweaks and a new part number is all that’s needed; other times, a complete redesign is in order.
Either way, HPD says it ensures compatibility and performance remain uncompromised.

You beauty
HPD says its commitment to performance doesn’t stop under the bonnet either, stating that it extends to aesthetics as well.
The team takes pride in creating components that not only work flawlessly but also look the part.
“We want you to look through the grille and under the bonnet and be as proud of the HPD brand as we are,” Rob says.
“This attention to visual design makes HPD products feel integrated rather than tacked on; an essential quality for discerning 4WD owners who care as much about style as they do about performance.”

The road ahead
As consumer expectations continue to rise and vehicle technologies grow more sophisticated, HPD says it remains firmly at the cutting edge.
“Our in-house R&D process is a blueprint for how aftermarket innovation should be done: grounded in real-world experience, validated through rigorous testing, and refined by a passion for excellence,” David said.
“You only have to buy a HPD product once.
“It’s a lousy business model, right?” he jokes, “but I hate things that you just throw away when they fail.
“Our products are designed to last a lifetime and if you have a HPD kit, we will supply you with whatever you need to keep it going forever! Put it in your next car.”
From humble driveways to punishing outback tracks, HPD says its products prove themselves again and again – not just in performance gains, but in reliability, ease of installation, and long-term value.
“It is not just about going further, it is about going smarter, stronger, and with total confidence,” David says.

For more information on HPD products, visit www.hpdiesel.com.au