Tuning Feature: Nissan MR18DE Modified

"Comprehensive guide to performance tuning the Nissan MR18DE engine!"

We are frequently getting messages requesting info on the best tips for MR18DE upgrades. So let us look into Nissan MR18DE parts and outline the best modifications on this great engine and point out some common pitfalls along the way.

Now we shall outline options for your MR18DE tuning and outline the best modifications. Nissan MR18DE great bases for a tuning project and with the ultimate tuning modifications like ECU maps, turbo kits and camshafts you will noticeably improve the drivers pleasure of your car.

The optimum MR18DE mods on an engine are in our opinion the ones that give the best value for money.

We won't be swayed by popular MR18DE mods, they need to be cost effective.

Altering your MR18DE camshaft will make a dramatic difference to your engines engines power. Choosing a higher performance camshaft profile raises the engines power .

NB: Fast road cams usually boost the performance through the rpm range, you could drop a little low end torque but the higher rpm power will improve.

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

For a daily driver one, ideally, must carefully try to match your bhp range to your driving style.

I'd never find a MR18DE Motorsport and race cam is a pleasure to live with when driving in heavy traffic.

Some MR18DE engines respond better to extreme camshaft durations so set your engine up on a rolling road.

The ecu map and fuelling also have a large bearing on the power gains you'll get.

Longer valve 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.

MR18DE Tuning Stages

Stage 1 MR18DE modifications: Panel air filters, Remaps/piggy back ECU, Intake headers, Sports exhaust manifold, Drilled & smoothed airbox, Fast road camshaft.

Stage 2 MR18DE modifications: Sports catalyst & performance exhaust, high flow fuel injectors, induction kit, Ported and polished head, fuel pump upgrades, Fast road cam.

Stage 3 MR18DE modifications: Internal engine upgrades (head flowing porting/bigger valves), Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions, Engine balancing & blueprinting, Competition cam.

ECU flashing should help to to establish the full potential of all the upgrades you've done to your MR18DE.

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

Getting air into each cylinder is the main goal to any car tuning project.

Intake manifold transmit the air during the suck phase from the intake filter and allow it to be pulled into the engine and mixed with fuel.

The bore size, shape and rate of flow of the Intake headers can make a noticeable change to fuel delivery on the MR18DE.

It's not uncommon that air intake manifolds are begging for aftermarket parts, although some manufacturers provide decently flowing air intake manifolds.

Fitting big valve kits, getting port matching and head flowing will also increase bhp and torque, and more importantly will give you a better bhp and torque increase on other upgrades.

Turbo upgrades for the MR18DE

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 MR18DE

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

If an engine is turbo charged mods are going to net you a larger power gain and we find turbocharged engines already contain better components.

There are common areas of failure for every engine, with some being over specified and some just sufficiently able to handle stock power

We recommend you find these limitations and fit better pistons and crank to utilize the power.

It's not unheard of people spending a lots of money on turbo upgrades on the MR18DE only to have the engine block catastrophically fail just after it's been finished.

Big capacity turbo chargers tend to experience no power at low rpm, and low capacity turbo chargers spool up more quickly but don't have the high rpm bhp gains.

Thankfully the market of turbos is always evolving and we now see variable vane turbos, allowing the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbos divert the exhaust flow into 2 channels and feed these at differently angled vanes in the turbocharger. They also improve the scavenging effect of the engine.

You'll commonly see there is a limitation in the air flow sensor (AFM/MAF/MAP) on the MR18DE when loads more air is being drawn into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped performance at a much lower level.

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

Uprating MR18DE fuel injectors

You will need to ensure that the engine is not starved of fuel so must ramp up the fuelling when you start exceeding 20% of a bhp and torque increase.We strongly recommend you to be generous with your flow rate on the injectors.

The accepted safe increase is to add 20% when buying an injector, this allows for injector deterioration and affords you some spare capacity should the engine require 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 MR18DE performance exhausts

You should look to increase your exhaust if your exhaust is actually causing a restriction in flow.

On most factory exhausts you'll find the exhaust flow rate is still fine 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 can help balance the flow of gases through the engine.

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

Usual exhaust restrictions come around the filters installed, so adding a freer flowing sports alternative will help avoid this restriction.

Problems and issues to look out for on the MR18DE

The MR18DE 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 MR18DE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your MR18DE engine please join us in our friendly forum where you can discuss tuning options in more detail with our MR18DE 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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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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