Tuning Feature: Nissan HR15DE Modified

"Comprehensive guide to tuning the Nissan HR15DE engine!"

We are always getting posts requesting information on the ultimate HR15DE mods that work. So let us look into Nissan HR15DE parts and outline the best modifications on this great engine and point out some potential pitfalls along the way.

The Nissan HR15DE are popular engines and with the right sports upgrades like remaps, turbo improvements and camshafts you will positively maximize your driving enjoyment.

In this article we review and look at HR15DE tuning and summarise the ultimate modifications.

The greatest HR15DE mods on an engine are usually the ones that give the best power gain for you spend.

We won't be swayed by popular HR15DE mods, they need to be cost effective.

Altering your HR15DE cam often will make a dramatic difference to your engines bhp. Choosing a higher performance cam profile raises the bhp .

NB: Fast road camshafts usually raise the torque across the rpm band, you could drop a little low down torque but your higher rpm power will be lifted.

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

On a car driven daily one, ideally, must carefully try to optimize your bhp range to your cars usage.

I'd be shocked if you have ever thought a HR15DE Motorsport cam is a pleasure to live with when driving around busy urban areas.

Some HR15DE engines respond better to extreme cam durations so set your engine up on a rolling road.

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

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.

Please watch TorqueCars Video tutorial on car tuning. And be sure to subscribe and support our new channel.

HR15DE Tuning Stages

Stage 1 HR15DE modifications: Fast road camshaft, Drilled & smoothed airbox, Sports exhaust manifold, Remaps/piggy back ECU, Intake headers, Panel air filters.

Stage 2 HR15DE modifications: induction kit, high flow fuel injectors, Fast road cam, Sports catalyst & performance exhaust, fuel pump upgrades, Ported and polished head.

Stage 3 HR15DE modifications: Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Competition cam, Crank and Piston upgrades to alter compression, Twin charging conversions.

ECU mapping should help to unlock the full potential of all the tuning parts you've done to your HR15DE.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the end result usually depend much on the tuning parts you've done and the condition of your engine.

Getting fuel and air into each cylinder is the main goal to any engine tuning task.

The intake plenum flow the air from the intake filter and allow it to be fed into the engine cylinders.

The size of bore and shape and rate of flow of the Intake headers can make a noticeable difference to to fuel delivery on the HR15DE.

I usually find intake headers are ripe for performance upgrades, although some OEM provide reasonably well designed intake headers.

Fitting big valve kits, getting 3 or 5 angle valve jobs and porting and head flowing will also lift bhp, & more importantly will permit increasing the bhp increase on other mods.

Turbo upgrades for the HR15DE

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 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 superb power gains.

If an engine has a turbo already fitted modifications are going to net you a larger power gain and turbo engines use uprated components.

However you'll find engines will have power limits

It is important to find these limits and fit better pistons and crank to cope with the power.

There are many people spending a lot of money on turbo upgrades on the HR15DE only to suffer the indignity of watching the whole thing explode just after it's been finished.

Larger capacity turbochargers tend to suffer a bottom end lag, and smaller turbochargers spool up more quickly but do not have the top end power band gains.

In recent times the choice of turbo units is always improving and we are seeing variable vane turbo units, where the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

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

It is common that there's a restriction 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 was restricting power at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although harder to get working. We have this article on twincharging if you want to read more.

Uprating HR15DE fuel injectors

You will need to ensure that the engine is not starved of fuel so need to increase the fuelling when you start going beyond 20% of a performance increase.Most tuners we speak with say to over specify your injectors flow rate.

The accepted safe increase is to add 20% when fitting an injector, this allows for injector deterioration and gives you some 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 HR15DE performance exhausts

You may need to boost your exhaust if your current exhaust is creating a restriction in flow.

On most factory exhausts you'll see the flow rate is still good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Sports exhausts balance the flow of gases through the engine.

But if your exhaust pipe is too big, ie: over 2.5 inches bore, you will lose much of the exhaust flow rate and end up lacking power and torque.

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

Problems and issues to look out for on the HR15DE

The HR15DE 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 HR15DE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your HR15DE engine please join us in our friendly forum where you can discuss tuning options in more detail with our HR15DE owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our HR15DE guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

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.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.