Tuning guide "HR12DE Modifications"

HR12DE Modifications Guide

How to modify and upgrade the Nissan HR12DE

"Comprehensive guide to performance tuning the Nissan HR12DE engine!"

Popular tuning sites like TorqueCars are frequently getting posts requesting information on how to improve the HR12DE from people wanting to know what are the premier HR12DE mods that work. So let us look into Nissan HR12DE mods and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

This pages aim is examine HR12DE tuning and outline the premier modifications. Nissan HR12DE make a good tuning project and with a few sensible sports mods like remapping, turbo improvements and camshafts you will noticeably increase your driving pleasure.

Just because particular modifications are appear in lots of HR12DE projects it doesn't mean its worth having, we shall focus on the ultimate modifications that will give your HR12DE the best power gain for you money.

Without us subscribing to the mentality of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

HR12DE induction kits

Improving air intake on the HR12DE

You need fuel and air for an engine to work. If there is little supply of fuel then it will run lean, if there is little flow of air it runs rich resulting in lost power which risks damage to the HR12DE. 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 aim to any performance tuning job.

It is common that there is a limit in the air flow sensor MAF/MAP on the HR12DE when loads more air is being fed into the engine.

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

Headers take the during the engines suck phase from the intake filter and allow it to be pulled into the engine cylinders.

The shape and flow characteristics of the Plenum can make a substantial improvement to fuel atomisation and engine efficiency on the HR12DE.

Many mass produced engine air intake manifolds are improved through a performance upgrade, although a few car makers provide reasonably well designed air intake manifolds.

Larger HR12DE valves, doing some HR12DE port enlargement and head flowing will also increase power, & importantly will allow you to get an improved power increase on other mods.

HR12DE performance cam tips.

Some HR12DE engines respond better to less aggressive camshaft durations so set your engine up on a rolling road.

The map and fuel pump and injectors also will make differences on the power gains you'll hit.

A longer valve duration can alter the power 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 bhp gains are on offer for cam upgrades.

NB: Fast road camshafts normally increase the bhp and torque throughout the rpm band, you may lose a little bottom end bhp but the higher rpm power will be better.

Competition camshafts, increase the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

On a road car you must carefully try to match your power band to your usage of the car.

You will never have ever thought a HR12DE Race cam is a pleasure to live with when on the daily commute.

Stage 1, 2 and 3 mods for the HR12DE

Stage 1 HR12DE parts:

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

Stage 2 HR12DE parts:

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

Stage 3 HR12DE parts:

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

Review your options and then acquire your upgrades and set yourself a power target to avoid costly mistakes.

Remaps helps unlock the full potential of all the mods you've done to your HR12DE.

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 the end result may vary depending on the mods you've carried out and the condition of your engine.

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

Turbo modifications on the HR12DE

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 HR12DE.

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.

When the engine is turbocharged, tuning mods are more reliable and you will discover turbocharged engines are made using uprated components.

There are tuning limits for every engine, with some being incredibly solid and some only able to handle stock power

See where you'll find these limitations and fit higher quality crank and pistons to handle the power.

We see many tuners spending a loads of money on turbo upgrades on the HR12DE only to have the whole thing throw a rod when it's been completed.

Larger upgraded turbochargers tend to experience no power at low rpm, and small turbochargers spool up much more quickly but don't have the high rpm bhp gains.

Over the last 20 years the market of turbo chargers is always moving on and we commonly find variable vane turbo chargers, where the vane profile is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo chargers divert the exhaust gases into 2 channels and feed these at differently angled vanes in the turbo charger. They also boost the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large power gains, although more difficult to configure. We have this article on twincharging if you want to read more.

Tips about fuel supply on the HR12DE

Don't miss you'll need to raise the fuel delivery when you are increasing the performance - it makes the car more thirsty. At this point we flag up the need to over specify your injector capacity.

As a rule of thumb add 20% to the flow rate when buying an injector, which takes into account injector deterioration and affords a little 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 HR12DE performance exhaust upgrades

You only need to to uprate your exhaust system with an upgraded one is if your exhaust is creating a restriction in flow.

On most factory exhausts you'll find the flow rate is still fine 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.

Do not go with the largest exhaust you can find this will 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.

Typically exhaust restrictions are traced to the catalyst and filters installed, so adding a better flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the HR12DE

Like most engines an HR12DE, 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 HR12DE, failure to do this will exacerbate engine wear, on a tuned HR12DE 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 HR12DE why not pop over to the forums at TorqueCars where you can chat about HR12DE tuning options and read about others projects who may be planning to do similar modifications on their HR12DE.

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