Estimated reading time: 8 minutes.
The HDJ79 1HD-FTE is one of the most capable diesel six-cylinders ever bolted under a bonnet. At 110HP and 320Nm in standard form it’s nowhere near what it’s capable of – and the good news is it responds beautifully to the right upgrades. This guide walks you through every stage of performance, what each part actually does, and the real decisions you’ll need to make.
What the HDJ79 Makes in Standard Form – and What It’s Capable Of
Stock, the HDJ79 with the 1HD-FTE 4.2L turbo diesel produces around 110HP and 320Nm at the wheels. It’s reliable, it’ll go forever, and it tows. But it struggles on highways, drops gears on hills, and anyone who’s driven one knows the feeling of wanting just a bit more.
The good news: the 1HD-FTE engine itself is genuinely tough. Even on 300HP+ packages, these engines barely break a sweat when modifications are done correctly. The engine is not your limiting factor – the factory Turbo, Clutch and Fuel system are.
Before you do anything: If your vehicle is high-kilometre, read our 1HD-FTE Recommended Maintenance Guide first. Having the correct done maintenance done beforehand makes upgrading easy.
The Big Decision: What Power Level Are You Actually Chasing?
Before you spend a dollar, you need to understand one thing that catches a lot of customers off guard: the standard Injectors are only capable up to a certain amount of HP, and your choice of standard, +30, or +50 High Flow will ultimately determine the horsepower range your HDJ79 will be capable of.
Here’s how the power ceiling actually works on the 1HD-FTE:
| Injector Spec | Power Range | Notes |
|---|---|---|
| Standard injectors | Up to ~220HP max | Standard Injectors Paired with a Turbo and Intercooler will produce this safely. |
| +30 High Flow injectors | 280HP – 330HP | Required to go beyond 220HP. Perfect with a UFI 18G or 21L Turbo. |
| +50 High Flow injectors | 330HP – 360HP | UFI 21L / 23L |
The 180HP Package – Best Bang for Buck
~180HP / 490Nm
1HD-FTE 180HP Performance Package – HDJ79 / HDJ78
~180HP
The most straightforward upgrade for a stock HDJ79. Three bolt-on parts, massive real-world improvement, no intercooler or clutch work required.
- Pre-Tuned Unichip UNI-X Pre Tuned to your vehicle with custom options and 5 map select (Power, Tow, Economy, stock + immobiliser)
- 3″ Turbo-Back Exhaust
- NPC 1300NM Clutch
This is the entry point and the one most stock HDJ79 owners choose first. The Unichip works with the factory ECU to increase fuel delivery and boost pressure, giving the engine the fuel it needs to use what the turbo is already producing. Your chip is tuned specifically for your setup before it ships.
The Manta 3″ exhaust frees up backpressure, improves low-down torque, and unlocks the sound of the 1HD-FTE straight-six as it should have left the factory. The factory exhaust runs as small as 2″ – it’s a genuine restriction even on a standard tune. A 3″ has enough flow for any power goal you can realistically reach on a 1HD-FTE – 180HP, 300HP, or beyond. 3.5″ and 4″ exist but are simply not necessary.
The 200HP Package – Add the Intercooler
~200HP / 550Nm
1HD-FTE 200HP Performance Package – HDJ79 / HDJ78
~200HP
Everything in Stage 1, plus a front mount intercooler and heavy duty clutch. The complete bolt-on package — no extra trips to the parts store.
- Pre-Tuned Unichip UNI-X – Pre Tuned to your vehicle with custom options and 5 map select (Power, Tow, Economy, stock + immobiliser)
- NPC 1300Nm Super Heavy Duty Clutch Kit
- PDI Front Mount Intercooler Kit – complete bolt-on with all piping and brackets
- 3″ Turbo-Back Exhaust
Why Add the Intercooler and Clutch?
PDI Front Mount Intercooler: The factory HDJ79 has no intercooler at all. Compressed air goes straight from the turbo into the intake at high temperatures meaning wasted potential and elevated EGTs, especially when towing or climbing. The PDI kit cools the charge air before it enters the engine: denser air, more power, lower EGTs. PDI Supply a full bolt-on kit, with all piping, brackets and even new custom Aircon Hoses included for fitment.
NPC 1300NM Clutch (Necessary at any stage): Even fitting just a Unichip will make a standard or generic heavy duty clutch slip. The torque increase from fitting a Unichip alone is enough. The NPC 1300Nm kit uses a custom Billet flywheel to accommodate a larger, Heavy Duty Pressure plate with no effect on pedal feel. We use it every single performance package we do. Don’t skip it, and don’t do it twice.
Turbo Notes:
If your factory turbo is on its way out and you want an improvement without committing to a fully aftermarket Turbo conversion like UFI, the GMT Billet from Munro Racing is worth knowing about.
The factory turbo in the HDJ79 is a CT20b. The GMT is a high-flow billet CT26A cartridge housed inside a factory CT20b housing – which means it bolts directly onto your standard intercooler piping, and intake pipe with zero modifications. These are only supplied on an exchange basis: send your old turbo core in, receive a freshly built unit back. Pairs well with Stage 2 and a Unichip tune.
Comparing Turbocharger options
The GMT Billet High Flow Turbo is good between 20-25psi(28psi max) which usually equates to around 280hp.
UFI make a true Performance Turbocharger, a brand new housing designed with no compromises. The UFI 18G will comfortably do 32Psi+ and handle up to 300hp. 21L and 23L Options are larger will go well beyond 350hp. UFI Turbos have a huge 4″ Anti-Surge Inlet, and therefore a much louder intake noise.
UFI Turbo Upgrade: More Air, More Potential
200–220HP std injectors
UFI Turbo Upgrade – 1HD-FTE (16G, 18G, 21L, 23L)
200–220HP
Bolt-on CT26 housing. Requires Unichip (boost cut removal) and PDI intercooler – both included if building from Stage 2.
- UFI Turbocharger – Comes in 16G, 18G, 21L, or 23L to suit your power goal
- All fitment hardware included- studs, nuts, gaskets
- Direct CT26 flange fitment – no manifold or dump pipe changes
- HDJ70 intake pipe required (available separately below)
Which UFI Turbo?
| Model | Std Injectors | +30 Injectors | Best For |
|---|---|---|---|
| UFI 16G | ~180–200HP | — | Smallest UFI Turbo, most response. |
| UFI 18G | ~200–220HP | ~300HP | Most popular. Peak torque below 2200RPM. Daily + tow sweet spot |
| UFI 21L | — | ~300–330HP | 300HP+ builds. Heart of the 330HP package |
All UFI turbos run a 4″ inlet and require an updated induction pipe. A bolt-on pipe is available to suit the factory HDJ79 airbox. The UFI also sits slightly further forward than the stock CT26, meaning the factory hot-pipe no longer aligns. This is another reason the PDI intercooler pairs so cleanly here, as comes with piping to suit the UFI turbo, meaning you have a bolt on ugprade package.
Airbox upgrade: The factory airbox becomes a restriction at around 250HP and above. Beyond that, the HD Auto high-flow airbox provides a much clearer path of cold air to the turbo. Even below 250HP it’s worthwhile — the turbo runs cooler and spools faster. Fits UFI and GTurbo inlet sizing only — does not fit the standard CT20b or GMT turbo.
High Flow Injectors – 300HP and Beyond
300HP – 330HP+
1HD-FTE 330HP Performance Package – HDJ79 / HDJ78
~330HP
The full performance package. Transform your HDJ79 into a beast with the UFI 21L + high flow injectors + PDI intercooler + HD Auto airbox + Manta exhaust + custom Unichip tune. This entire package can still be supplied pre-tuned and shipped together.
- UFI 21L Turbocharger
- +30 High Flow Injectors
- PDI Front Mount Intercooler
- HD Auto High Flow Airbox
- Manta 3″ Turbo-Back Exhaust
- Pre-Tuned Unichip – tuned specifically for this combination
Standard injectors cap at around 220HP regardless of turbo or tune – they simply can’t deliver enough fuel beyond that point. The +30 injectors unlock the full potential of the UFI 21L and a custom Unichip tune, delivering 300–330HP and 700–800Nm.
For those wanting even more – the injector range extends to +50 (330–360HP, UFI 23L) and +70/+90 (350–440HP, purpose-built territory where engine internals become part of the conversation).
Engine Reliability at High Power
The 1HD-FTE is a genuinely tough engine. Even at 300HP+ with high flow injectors, we don’t experience internal problems – not even at high kilometers. We’ve torn apart motors with half a million kilometers on them and found barely any wear to the pistons or rotating assembly when they’ve been looked after and modified with quality parts.
What we do recommend before any serious power upgrade is a fuel system service. The factory injector pump is capable of supporting over 400HP when healthy. If it’s old and worn, replace it with a genuine new unit. If yours is healthy, leave it alone. Same goes for injector lines – if they’re looking old or crusty, replace them while you’re in there.
See our full 1HD-FTE Recommended Maintenance Guide for everything to check before you start modifying.
Frequently Asked Questions
Can I bolt on an upgraded turbo without a Unichip?
No – this is a very common mistake. The factory ECU has a boost cut at 14psi (Triggered by maxing out the 5V MAP Sensor where 5V = 14PSI). An upgraded turbo will spike past that on its own wastegate pressure and the ECU cuts power immediately. The Unichip clamps the MAP sensor voltage and takes control of the fuel delivery – it’s essential with any turbo upgrade.
My factory turbo just blew – should I upgrade at the same time?
Yes, absolutely it’s the ideal time. If the budget allows for it we would highly recommend fitting the UFI Turbo with a Unichip and PDI intercooler at minimum. It’s a great opportunity to step the whole vehicle up in one go.
Do I need a bigger exhaust for 300HP+?
A 3″ Manta exhaust has enough flow for any power level you can realistically make on a 1HD-FTE, including 300HP+. 3.5″ and 4″ systems exist but are not necessary for any street or towing build at these power levels.
Why should I upgrade the Airbox/Snorkel?
The Factory airbox starts to become restrictive above 250hp+ and becomes a necessity above 300HP. However it is absolutely worth upgrading your intake at any stage of performance, providing a clear path of air to your Turbocharger allows it to make the power while working less hard and with lower wheel speed. There is literally no downside to providing better airflow to your Diesel engine.
Do I need an injector pump upgrade?
For the vast majority of customers, no. The factory pump supports 400HP+ when healthy. If it’s genuinely worn, replace with a genuine new unit. Don’t recondition.
Any Questions?
Text our HD Auto text line anytime: 0483 906 923. We build these packages in our Brisbane workshop every week and are happy to walk you through the right gear for your Cruiser before you buy.
Related reading:
1HD-FTE Recommended Maintenance Guide (High KM)
Complete 1HD-FTE Performance & Tuning Guide
