When it comes to the tradie ute range that spawned the Aussie fixation with 4X4 pickups, you don't need to look any further than the Toyota HiLux. With generations spanning decades, the HiLux is a great base to use as a tuning platform; after all, they are 'un-bloody breakable,' or so the story goes.

Over the years, the HiLux has been available with a range of different engines and transmissions. Rather than cover them all, we'll focus on the 2006-model N70 HiLux (3.0 D4D engine) and its replacement, the 2015 N80 HiLux with the later-generation 2.8 Common Rail Diesel.

These are the most popular models with tuners and most widely-available on the used market. Like a lot of vehicles we look at in these guides, there's a lot of stuff that works and plenty that doesn't. Let’s separate fact from fiction.

WORDS BY MARTIN DONNON, IMAGES BY ARNOLD ARCHIVE

The Toyota HiLux is revered as being ‘un-breakable’ but the recent DPF scandal has rocked its reputation. Here’s what you need to know about getting more power and torque from the N70 and N80 HiLux.

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Flash tuning, performance chips and estimated power gains
Both the N70 and N80 show substantial torque and power gains with simple ECU adjustment and no other hardware changes. The tuning price can vary substantially between different shops depending on their reputations and ability but expect to pay no more than around $1600 for a custom flash tune on an otherwise standard Hilux.

Like other diesel flash tuning, this technology is still in its infancy in Australia, with few shops custom tuning. Most rely on a handful of third parties to supply pre-programmed files. While there is nothing inherently wrong with this approach, it's vital to have a before-and-after dyno reading to monitor air-fuel ratio and boost levels.

The N70 HiLux engine – the 3.0 D4D 1KD-FTV – is a solid performer. Its power and torque were good for the time but are now way off the pace, which makes tuning upgrades worthwhile. As we have shown with the attached dyno sheets, the stock 126kW and 343Nm can jump by 15-20kW and more than 100Nm of torque, and that's at the wheels. Boost settings and fuelling on the D4D is conservative from the factory, so expect this sort of gain without sacrificing reliability.

Boost targets for the N70 should stay at around 18psi, which is only a handful of psi over stock boost pressure, and the reasons for this are two-fold. The N70 engine has a tiny turbocharger and similarly small top-mount intercooler, and both are susceptible to performance-stifling heat soak if boost pressure exceeds 18psi.  More on that later.

Plug-in chips will also need to be tuned on the dyno to get the best result but beware of cheap 'rail pressure adjuster’ types. While some can indeed work well, others can and will melt your engine. See the below dyno sheets to get an indication of a custom flash tune versus a plug-in type.

The N80 Hilux, with its GD series engine, runs a lower compression ratio than the N70 HiLux and a bigger turbocharger, too, which helps it make 100Nm more torque than the engine in the N70. The turbocharger in the N80 delivers low-down torque (compared with the N70), and you can expect similar gains of 15-20kW and 110Nm of torque at the wheels, but with both peak power and torque produced lower in the rev range. If your tune has been carried out by a reputable business using a dyno, then there's almost no downside. As a side note here, a good tuner will not only get you some substantial gains on your Hilux but also, particularly in the case of the N80, be able to improve fuel economy too.

“A good tuner will not only get you some substantial gains on your Hilux but also, particularly in the case of the N80, be able to improve fuel economy too”

Exhaust upgrades
Don't expect significant gains in power or torque by fitting an aftermarket exhaust to your HiLux. An aftermarket exhaust will return a slight torque gain and a small drop in exhaust gas temperatures, but it's worth balancing the cost with the return.

And then there's the N80's 'DPF-gate,' which has prompted owners to launch a class action against Toyota for allegedly installing faulty DPFs into HiLux and Prado. Owners have complained of the DPF blocking and the vehicle ending up in limp mode. And, beyond the reputational damage to the HiLux, it has led to a growing and illegal trade in DPF deletes.

So, just what is the problem with the DPF in the N80 HiLux? The answer is/was simple, and it's all because of the software. The DPF regeneration procedure in the HiLux wasn't frequent enough for some driving conditions, like owners who only drove short distances. Owners of N80 HiLuxes, who drove longer distances didn't experience any issues. For the DPF to complete its regeneration process, the vehicle must reach a 'certain' temperature, which is only possible when running for a certain distance at, say, more than 80km/h.

ABOVE The N80 has suffered a severe reputation knock because of premature DPF blocking issues causing the vehicle to go into limp mode. Some owners have resorted to removing the DPF.

BELOW Following TopGear’s destruction test of a HiLux, Toyota launched a series of TV Ads promoting the HiLux as ‘un-breakable’. DPF-Gate has busted that myth.

The DPF 'fixes' implemented by Toyota are a software update, to prompt more frequent 'DPF Burns' and, in some instances, the fitment of a manual 'DPF Burn' button, which allows the end-user to carry out the regeneration procedure at their leisure.

But, DPF-Gate has damaged the N80's reputation. And there are now hundreds and maybe thousands of them on the roads with the DPF removed and the ECU flash tuned to shut down the regeneration process. Is there any significant power or torque gains to be had by doing this? Short answer - no. But that's not the reason people have removed the DPF from their N80 HiLux. Those we've spoken to who have deleted the DPF weren't looking for more power; they didn't want it blocking, causing them to limp down the road at 30km/h.

Intercooler upgrades
The N70 HiLux has a small top-mounted intercooler, so an upgrade makes a lot of sense, and there are plenty of alternatives available, from upgraded top mount intercoolers through to a properly engineered front-mount intercooler.

The N80, on the other hand, has a decent front-mount from the factory that can last a couple of hot-pulls before it starts to heat-soak and reduce performance. Under high-load conditions, the N80's front-mount intercooler easily outperforms the N70's top-mount setup, but both fade fast in high-stress situations (think: off-roading and towing).

Our choice for either HiLux variant would always be a quality front-mount intercooler, a proven core material and backed by real-world test data, and not just a dyno sheet. In the world of climate-controlled dyno cells with plenty of cool-down allowed between runs, the expectation (and reality) of getting a few extra kilowatts or Newton-metres from an upgraded intercooler is not the point. When searching for a new intercooler, shop local, and make sure the company has tested its product in the real world (there are plenty of Australian companies that do this).

Turbocharger upgrades
While both N70 and N80 turbochargers suited to the standard engines, the popularity of the HiLux means there are plenty of choices for those looking for more performance (think: up to 50kW more at the wheels).

If you are looking for more 'go' from you HiLux, there are plenty of well-known brands providing off-the-shelf products that will deliver up to 200kW and torque to match at the wheels. Think GCG Turbochargers, G-Turbo, Just Autos, and G&L, to name just a few.

It's worth noting that more airflow and power at the top of the rev-range will mean giving up some low-down torque. There is no workaround here. So, don't think that bolting on a larger turbocharger will give you significant power gains without also adjusting the fuelling to match. And here is where it goes from an art to a science.

Fuelling upgrades and the ‘package’  
Larger +30 injectors are the heart and soul of making more than, say, 140kW at the wheels. The reason for this is that no matter what kind of tuning solution you go with, the factory fuel system will always be the limiting factor.

The companies we mentioned earlier (Just Autos and G&L) both have larger +30 injector kits available for HiLux (as do several others – do your research here). You can't simply plug in larger injector kits and expect anything other than horrendous fuel consumption and lots of black smoke. Careful tuning is required to match the injectors to the turbocharger's response curve, and this can be done in several different ways.

It would seem only the very best of the 'flash tuners' can control the +30 injectors correctly low-down in the rev range. It can be done via a custom flash, but you need to interview your tuner carefully to make sure they can control the injector properly. No doubt, as more experience is gained on the factory ECU, this will become more straightforward and acceptable, but sophisticated 'chip' solutions are the flavour of the month.

A big injector and turbo combination will come as a package, so those doing the selling and installation will know what kind of 'chip' to supply. But bear in mind these chips need to be sophisticated to both directly drive the injector and be fully programmable; they will come at a decent cost. No cheapie special off the Internet will get the job done right here.

The good news is there are plenty of companies out there supporting both HiLux platforms (N70 and N80), so you won't have to do to much searching to find a reputable and reliable tuner.

What else do I need to know?
The HiLux across all its iterations forged the reputation (some real, some via intelligent marketing) as being 'unbreakable', but obviously, this is a fair stretch of the truth. Just like anything else with an engine, transmission, and wheels these things can and will let you down if overly abused or not maintained properly. Fortunately, the list of common problems with either model is short.

Injector seals are a known issue on the N70, where premature failure can cause contamination of the crankcase, which in some extreme examples led to engine seizing and warranty comebacks for the manufacturer. It's vital that, as part of any long-term ownership,  the injector seals be replaced by a diesel professional and then stick to their recommended service guidelines.

The N80 suffered a few hiccups, too, with reports of the inlet system design not being adequate and allowing contamination of the airflow meter, which in turn leads to premature limp-mode. The most notable of the N80's comes back to the DPF and its well-documented cases of early blockage.

Pump up the jam
The HiLux is a darling of the 4X4 tuning scene. Relatively lightweight with robust engines, along with the sheer weight of numbers, has made them a fantastic base for those that want to push the envelope for road-going performance. So, how fast can a HiLux go? The answer is GTR-beating fast.

A quick search of Youtube will give you a list of 10- and 11-second N70s, and we figure that in time, the N80 will be doing the same thing. No, we don't consider these vehicles would be street-able, economical, or reliable, but the videos are good for a giggle. As far as 'quickest' and 'fastest' where modified is concerned, the HiLux platform seems to have it all over the competition.