Tuners tips on "TD42T Modifications"

How to modify and upgrade the Nissan TD42T

"Comprehensive guide to tuning the Nissan TD42T engine!"

Let's embark on a journey into the robust world of the Nissan TD42T engine – a stalwart in the realm of reliable and durable diesel powerplants.

The TD42T, introduced in the 1980s, is a six-cylinder, turbocharged diesel engine that has become an iconic workhorse, primarily powering Nissan's rugged off-road vehicles, including the Patrol series.

This engine exemplifies Nissan's commitment to providing dependable performance in demanding conditions.

In terms of specifications, the TD42T features a 4.2-liter displacement, showcasing Nissan's emphasis on torque and durability. Turbocharging enhances the engine's efficiency and power output, making it well-suited for both on-road and off-road applications.

The TD42T proudly features an overhead valve (OHV) design, a configuration known for its simplicity and durability. This design choice aligns with the engine's intended use in challenging environments, where reliability and ease of maintenance are paramount.

What sets the TD42T apart is its reputation for robustness. Constructed with a cast-iron block, this engine is renowned for its durability under heavy loads and in harsh terrains.

The turbocharging adds a punch to its performance, making it a popular choice for those seeking both strength and torque.

As we explore the intricacies of the TD42T, we witness the embodiment of Nissan's dedication to creating engines that stand the test of time. The TD42T remains a favorite among off-road enthusiasts and professionals alike, known for its reliability, longevity, and the unmistakable torque that propels vehicles through challenging landscapes.

The Nissan TD42T engine stands as a testament to the enduring legacy of robust diesel powerplants. Its role in the Nissan Patrol series echoes the brand's commitment to providing vehicles that conquer the toughest terrains with unwavering reliability. The TD42T is not just an engine; it's a symbol of durability that has carved its place in the heart of the off-road community.

TorqueCars are always getting posts requesting info on how to improve the TD42T from people inquiring about getting more power from the TD42T and wanting to know what are the best tips for TD42T power upgrades. So let us look into Nissan TD42T upgrades and outline the best modifications on this great engine and point out some problems along the way.

Now we shall detail the best approach to TD42T tuning and point out the greatest upgrades. Nissan TD42T have loads of potential and with a few sensible motorsport parts like remapping, turbo improvements and camshafts you will definitely increase your driving experience.

When talking about the best parts for your TD42T engine, we are going to focus on the mods that give the best value for money.

Improving air intake on the TD42T

You need air and fuel for an engine to work. If there is a lack of fuel then it will run lean, if there is not enough air it runs rich sapping power and potentially damaging the engine. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pulling more air and fuel into each cylinder is the primary aim to any performance tuning job.

It is not unusual that there is a restriction in the air flow sensor AFM/MAF on the TD42T when considerably more air is being pulled into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp at a much lower level.

Headers transmit the on the suck phase from the filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

Design and flow rate of the Plenum can make a big improvement to fuel mixing and power on the TD42T.

Commonly we find the air intake manifolds are begging for aftermarket tuning parts, although a few car makers provide decently flowing air intake manifolds.

Fitting big valve kits, getting port work and head flowing will also increase bhp, and importantly will make space for an improved bhp increase on other mods.

TD42T performance cam tips.

Each engine responds better to more or less aggressive camshaft durations so set your engine up on a rolling road.

The ECU mapping and fuelling also will say much on the bhp gains you'll hit.

Extending exhaust or intake durations can alter the bhp band and on most engines the exhaust and intake durations do not need to match, although most cams and tuners use matched pairs there are some advantages to extending the intake or exhaust durations.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen cam profile, so large power band gains are on offer for cam upgrades.

NB: Fast road camshafts commonly raise the bhp and torque across the rpm band, you may lose a little low end torque but top end will be better.

Motorsport camshafts, raise the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport cam is not great in heavy traffic.

You should ideally optimize your bhp range to your driving style so for a car used daily stick with a shorter duration TD42T cam

Stage 1, 2 and 3 mods for the TD42T

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

1. Suspension Upgrades - always improve your cars handling
2. Brake Upgrades - Even before adding power improve those brakes
3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
6. Fuelling - when you've increased power you'll need to match this with more fuel
7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 TD42T parts:

Drilled & smoothed airbox, Remaps/piggy back ECU, Sports exhaust manifold, Fast road camshaft, Intake headers, Panel air filters.

Stage 2 TD42T parts:

fuel pump upgrades, induction kit, Ported and polished head, high flow fuel injectors, Fast road cam, Sports catalyst & performance exhaust.

Stage 3 TD42T parts:

Competition cam, Crank and Piston upgrades to alter compression, Engine balancing & blueprinting, Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves).

Remapping should help to release the full potential of all the tuning parts you've done to your TD42T.

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results often vary depending on the tuning parts you've done and the condition of your engine.

Turbo modifications on the TD42T

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have found a great guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the TD42T.

The more air you can get into an engine, the more fuel it can burn and uprating the induction with a turbocharger upgrade makes significant power gains.

When a car has a turbocharger tuning parts are going to make more power and you'll see that turbocharged engines are built with stronger components.

However engines will need better parts at higher power limits

Research these limits and upgrade to better quality components to handle the power.

There are many mechanics spending a loads of money on turbo charger upgrades on the TD42T only to have the TD42T catastrophically fail just after it's first rolling road session.

Larger capacity turbo units will usually experience a bottom end lag, and small turbo units spool up more quickly but won't have the high rpm bhp gains.

Thanks to new tech the world of turbos is always improving and we commonly find variable vane turbos, permitting the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbos divert the exhaust flow into a couple of channels and flow these at differently angled vanes in the turbo. They also help the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp gains, although more challenging to get working. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the TD42T

When you lift the power you will need to look at to the fuel delivery.

More power needs more fuel. It makes sense to over specify your flow rate on the injectors.

The accepted safe increase is to add another 20% when buying an injector, helps cope with injector deterioration and allows you some spare capacity should the engine need more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

Recommended TD42T performance exhaust upgrades

Only look to uprate your exhaust system with an upgraded one is if your exhaust is actually creating a flow problem.

On most factory exhausts you should find that your flow rate is still good even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Don't go with the biggest exhaust you can buy you'll reduce the exhaust flow rate - the best for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

Usual exhaust restrictions can be located the emissions filters installed, so adding a higher flowing race alternative will help avoid this restriction.

Decatting (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the TD42T

Like most engines an TD42T, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the TD42T, failure to do this will exacerbate engine wear, on a tuned TD42T this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your TD42T why not pop over to the forums at TorqueCars where you can chat about TD42T tuning options and read about others projects who may be planning to do similar modifications on their TD42T.

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This entry was posted under Makes and Models. Tags: engine, nissan
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