HPD recently developed the Series 2 version of its popular top-mount intercooler kit for the 70 Series Landcruiser V8

Australian performance product manufacturer High Performance Diesel designs, develops and manufactures upgrade products for a wide range of turbo-diesel vehicles.
Made in Australia from high quality materials, HPD says its products improve performance, efficiency and longevity on and off-road.
The process of developing new products is carried out entirely in-house by HPD, with its most recent project being the Series 2 version of its popular top-mount intercooler kit for the 70 Series Landcruiser V8.

HPD founder Dave Mitchell purchased a 2016 Landcruiser with just 11,000km on the clock to be the platform for development and testing.
The vehicle was run on the dyno to establish benchmarks, recording peak power of 106.4kW at the wheels. Torque from the stock motor was 320Nm, with boost pressure of 9psi. The temperatures from the standard intercooler were measured, with hot air from the turbo entering the intercooler at up to 85°C and leaving at around 45°C.
On a dyno on a winter morning, HPD explains these numbers seem reasonable, but when the engine is under load, such as when towing, working hard off-road or in extreme Australian heat, OEM intercoolers struggle to keep up and the temperatures start to rise. The hotter the air gets, the less dense it becomes, which means less oxygen for combustion in the engine.
This leads to reduced power and torque, reduced efficiency and economy, and higher operating temperatures that reduce engine longevity. In vehicles that have been tuned for increased power, the intercooler is put under even more pressure, and can become a limiting factor in engine performance.
HPD’s new intercooler was designed to address these problems, while also delivering a more robust design which it says is less prone to leaks down the track.

Creating a new design
With these benchmark figures set, work began on the new design. To be more effective, the HPD intercooler needed to have a larger core than the stock unit, but it still needed to fit in the same space between the engine and the bonnet while allowing clearance for other accessories such as fuel filters, dual batteries and of course the HPD catch can.
In order to fit a deeper, wider core, the inlet and outlet were shifted from the sides of the cooler to underneath, allowing extra size without taking up excessive space.

Dave began by mocking up an intercooler from the larger core using sheetmetal for the end tanks and fittings. This prototype was fitted to the new Cruiser, along with the new twin thermofan setup, to ensure all measurements were correct and the fit was precise.
This process also allowed Dave and his team to determine dimensions for piping and mounting brackets, so the end product would be a bolt-in replacement.
Once the prototype’s dimensions were determined, it went to HPD’s CAD department, where the design was refined in preparation for full-scale manufacture. With the design finalised, the CAD files were put to work in HPD’s CNC mill.
The end tanks of HPD intercoolers were CNC machined from billet aluminium, then the core, tanks, brackets and inlet/outlet were TIG-welded into a lightweight, durable, uniform structure. Unlike the crimped-on tanks of OEM intercoolers, HPD says this construction method meant there are fewer potential weak points in the system where leaks can develop over time.
The first intercooler made from the CAD design was measured on a precision jig to ensure its dimensions were correct. Once these measurements were recorded, it was time to install the unit on the vehicle and unsurprisingly, says HPD, it fit perfectly.

Completing the kit
The next task was to complete the kit with ancillary items such as hoses, alloy piping, clamps, fittings and fasteners.
Unlike many aftermarket kits, HPD says its products come with everything required for a bolt-in replacement of the OEM intercooler.
Rubber hoses are largely replaced by durable hard alloy piping that won’t perish or split, with high quality silicon hose where flexibility is required. HPD explains its kits also come with comprehensive fitting instructions that make installation straightforward for professionals and enthusiasts alike.
With all elements of the kit measured and defined, the Landcruiser headed off to the dyno for testing and a tune to make the most of the extra airflow that was now available.
Rolling on HPD’s 4WD dyno with the HPD Series 2 intercooler and a new three-inch exhaust, HPD reports the Cruiser now peaks at 124.7kW, an 18 percent increase over stock, while torque is also up to almost 400Nm. The company reports that these gains come purely from the engine’s improved breathing.

STD: The standard intercooler cools air to 45 degrees
AFTER: The red line shows standard power and torque. The blue line shows results with HPD intercooler and three inch exhaust. The green line shows final results after HPD ECU remap.
TEMPS: The red lines show hot side and cold side temperatures for the standard intercooler, the blue lines show the HPD Series 2 intercooler temperatures, which are around 20 degrees lower than stock. The hot side temperatures are higher due to the slight increase in turbo boost from the three inch exhaust.

Making the most of it
HPD says the next step was a HPD ECU remap to make the most of the extra air coming in through the intercooler.
This leaned out the mixture, so returning it to close to stock levels and raising the turbo boost to a peak of around 22psi delivers 162.9kW, more than 50 percent better than stock, with torque around 650Nm.
In this case, HPD says it is the temperature readings they are most interested in. Before the tune, the air temperatures on the way into the engine held steady at around 25 degrees Celsius, even when the engine was pushed hard – 20 degrees cooler than stock.
Crucially, after the tune, HPD reports that when the extra turbo boost raises the temperatures on the way into the intercooler to more than 130 degrees under load, the air temperatures on the way out never top 30 degrees. In the real world – when towing, driving in tough conditions and extreme heat – it is this improvement that will provide performance and protection in the long term, it says.

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