Tuning Feature: Nissan HR12DDT Modified

"Comprehensive guide to performance tuning the Nissan HR12DDT engine!"

We are always getting posts about the best HR12DDT upgrades. So let us look into Nissan HR12DDT tuning mods and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

The Nissan HR12DDT provide a fun base for your project and with carefully chosen performance tuning mods like remapping, turbo improvements and camshafts you will substantially maximize your driving opportunities.

Our aim here is to look at HR12DDT tuning and provide tips on the best modifications.

When talking about the best parts for your HR12DDT engine, we are going to concentrate on the tuning parts that give the best power gain for you spend.

Significant power gains can be made on engines, and the HR12DDT is no exception, by means of camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams commonly bump the torque throughout the rev band, you could sacrifice a little low down torque but higher rpm power will be better.

Race cams, bump the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Motorsport and race camshaft is not great on the daily commute.

You should ideally match your bhp range to your preferences so for a typical daily driver stick with a mild fast road HR12DDT camshaft

Some HR12DDT engines respond better to extreme cam durations so view each engine as unique.

The ecu map and fuel pump and injectors also will make differences on the bhp gains you'll get.

Longer valve 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.

HR12DDT Tuning Stages

Stage 1 HR12DDT modifications: Remaps/piggy back ECU, Drilled & smoothed airbox, Sports exhaust manifold, Fast road camshaft, Intake headers, Panel air filters.

Stage 2 HR12DDT modifications: Ported and polished head, Sports catalyst & performance exhaust, high flow fuel injectors, fuel pump upgrades, Fast road cam, induction kit.

Stage 3 HR12DDT modifications: Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Competition cam, Crank and Piston upgrades to alter compression.

Remaps helps release the full potential of all the upgrades you've done to your HR12DDT.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your results often rely on the upgrades you've done and the condition of your engine.

It is the main goal to any performance tuning task to feed more fuel and air into the HR12DDT engine

Air Intake manifolds take the air during the suck phase from the filter and allow it to be pulled into the engine cylinders with fuel for the squish phase.

Design and flow rate of the Air Intake manifolds can make a noticeable improvement to fuel atomisation and engine efficiency on the HR12DDT.

Many mass produced engine plenum chambers are in desperate need of performance upgrades, although a few makers provide fairly well optimized plenum chambers.

Adding a HR12DDT larger valve kit, doing some port work and head flowing will also raise torque, and significantly will permit a better torque increase on other tuning parts.

Turbo upgrades for the HR12DDT

NASP engines need quite a lot of work when you add a turbo, so we have a separate guide to help you take into account the pros and cons of going this route on your HR12DDT

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

If your car is fitted with a turbo modifications are going to make more power and you will discover turbo charged engines are made using harder and stronger components.

However most engines have weakspots

Discover these restrictions and install forged components to handle the power.

There are many drivers spending a lots of money on turbo charger upgrades on the HR12DDT only to experience the engine go up in smoke on it's first outing after it's used on the roads.

Large upgraded turbochargers tend to experience a bottom end lag, and smaller turbochargers spool up much more quickly but don't have the top end power band gains.

Thanks to new tech the world of turbo units is always developing and we are seeing variable vane turbo units, allowing the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo units divert the exhaust flow into two channels and flow these at differently angled vanes in the turbo. They also improve the scavenging effect of the engine.

You'll commonly see there's a limit in the air flow sensor AFM/MAP on the HR12DDT when considerably more air is being sucked into the engine.

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

Adding a supercharger or additional turbo will make large bhp gains, although more difficult to configure. We have this in depth look at twinchargers if you want to read more.

Uprating HR12DDT fuel injectors

When you increase the torque you will need to ramp up to the fuelling.

More torque needs more fuel. We strongly recommend you to over specify your injectors flow rate.

The accepted safe increase is to add 20% capacity when buying an injector, helps cope with injector deterioration and gives a bit of spare capacity should the engine need more fuel.

We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well.

Best HR12DDT performance exhausts

You should look to increase your exhaust if your exhaust is creating a flow problem.

On most factory exhausts you should find that the exhaust flow rate is fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Don't go with the largest exhaust you can find you'll slow the exhaust rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions are in the filters installed, so adding a higher flowing race alternative will help avoid this restriction.

Problems and issues to look out for on the HR12DDT

The HR12DDT engines, if regularly serviced and maintained, are generally very reliable and have few issues. {But if neglected they can cost a small fortune|When neglected they get very expensive to run|They can however be quite expensive if neglected| }

Regular oil changes are vital on the HR12DDT, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your HR12DDT engine please join us in our friendly forum where you can discuss tuning options in more detail with our HR12DDT owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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We really like hearing from our readers, and hearing about which tuning mods were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our HR12DDT guides and tips are kept up to date.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Nissan. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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