Modding uprating the Nissan HR15DE engine!

Car tuning tips:HR15DE Modifications"

HR15DE Modifications Guide

How to modify and upgrade the Nissan HR15DE

"Comprehensive guide to tuning the Nissan HR15DE engine!"

Forums like the one at TorqueCars are regularly getting messages about how to improve the HR15DE from people inquiring about getting more power from the HR15DE and wanting to know what are the best tips on HR15DE upgrades. So let us look into Nissan HR15DE parts and outline the best modifications on this great engine and point out some problems along the way.

Car Tuning Tips will review HR15DE tuning and outline the best modifications. Nissan HR15DE really good project engines and with carefully chosen motorsport upgrades like remapping, turbo upgrades and camshafts you will definitely increase your driving pleasure.

Just because particular parts are appear in lots of HR15DE projects it doesn't mean you should fit it, we shall concentrate on the best parts that will give your HR15DE the best power gain for you spend.

Without us subscribing to the popular myth 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'.

HR15DE induction kits

Improving air intake on the HR15DE

You need fuel and air for an engine to work. If there is too little fuel then it will run lean, if there is too little air it runs rich losing power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the whole point to any engine tuning project to shove more air and fuel into each cylinder but this has a knock on effect with the air flow sensor.

It is common that there's a limitation in the air flow sensor MAP/MAF/AFM on the HR15DE when a lot more air is being drawn into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped torque at a much lower level.

Intake headers carry the during the engines suck phase from the air cleaner and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The shape and flow rate of the Intake can make a large effect on to fuel atomisation and engine efficiency on the HR15DE.

On popular production engines intake manifold are improved through aftermarket tuning parts, although a few OEM provide reasonably good intake manifold.

Fitting big valve kits, carrying out port matching and head flowing will also improve performance, this will afford you a greater performance increase on other upgrades.

HR15DE performance cam tips.

Different HR15DE engines respond better to extreme camshaft durations than others.

The map and injectors and fuel pump also will say much on the power gains you'll achieve.

Extending exhaust or intake durations 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 camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake and exhaust durations will alter depending on the chosen camshaft profile, so large bhp gains are on offer for camshaft upgrades.

NB: Fast road camshafts tend to boost the power throughout the rpm range, you could sacrifice a little low end torque but the high end rpm power will be lifted.

Motorsport and race camshafts, boost the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

For a daily driver you must carefully try to optimize your torque band to your cars usage.

You'll never have found a HR15DE Motorsport cam is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the HR15DE

Stage 1 HR15DE parts:

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

Stage 2 HR15DE parts:

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

Stage 3 HR15DE parts:

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

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

ECU flashing allows a tuner to unlock the full potential of all the parts you've done to your HR15DE.

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 usually rely on the parts you've fitted 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 HR15DE

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 HR15DE.

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 motor is fitted with a turbo modifications are going to make more power and most turbocharged engines are built with better components.

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

Discover these limitations and upgrade to stronger pistons, crank and engine components to survive the power.

We see many people spending a a stack of money on turbocharger upgrades on the HR15DE only to have the engine literally blow up just after it's been completed.

Larger upgraded turbochargers will usually experience a bottom end lag, and small turbochargers spool up quickly but do not have the high rpm engines power gains.

Thanks to progress the world of turbochargers is always moving on and we now see variable vane turbochargers, permitting the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbochargers divert the exhaust flow into a couple of channels and flow these at differently angled vanes in the turbo charger. They also improve 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 and torque gains, although more complex to install. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the HR15DE

You will need to ensure that the engine is not starved of fuel so will have to pay attention to the fuelling when you start extending past 20% of a bhp and torque hike. Experienced mechanics will tell you to be generous with your injector capacity.

As a rule of thumb add 15% to the flow rate when fitting an injector, this allows for injector deterioration and provides 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 HR15DE performance exhaust upgrades

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

On most factory exhausts you'll see your flow rate is ok 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.

Sports exhausts increase the flow of air through the engine.

But if your exhaust is too large, ie: it's over two and a half inches diameter, you will lose much of the exhaust flow rate and end up sapping power and torque.

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

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

Faults issues and things to look out for on the HR15DE

Like most engines an HR15DE, 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 HR15DE, failure to do this will exacerbate engine wear, on a tuned HR15DE 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 HR15DE why not pop over to the forums at TorqueCars where you can chat about HR15DE tuning options and read about others projects who may be planning to do similar modifications on their HR15DE.

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