Tuning Feature: Nissan MR20DD Modified

"Comprehensive guide to tuning the Nissan MR20DD engine!"

We are always getting messages requesting info on the things we are recommending when it comes to MR20DD modifications. So let us look into Nissan MR20DD parts and outline the best mods that work on this great engine and point out some frequent tuning mistakes along the way.

The Nissan MR20DD great bases for a tuning project and with the right parts like remaps, turbo improvements and camshafts you will enhance your driving fun.

We shall review and look at MR20DD tuning and report on the best modifications for your car.

When talking about the best parts for your MR20DD engine, we are going to focus on the mods that give the best power gain for you spend.

Altering your MR20DD camshaft will make a dramatic difference to your engines power band. Choosing a higher performance camshaft profile raises the power band especially at the top end.

NB: Fast road camshafts commonly push up the performance through the rev range, you may lose a little low end bhp but the top end will be better.

Motorsport camshafts, push up the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a daily driver one, ideally, must carefully try to match your engines power to your preferences.

I'd be amazed if you find a MR20DD Competition cam is a pleasure to live with when driving around busy urban areas.

Different MR20DD engines respond better to less aggressive camshaft durations so view each engine as unique.

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

Altering 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.

MR20DD Tuning Stages

Stage 1 MR20DD modifications: Intake headers, Fast road camshaft, Drilled & smoothed airbox, Panel air filters, Sports exhaust manifold, Remaps/piggy back ECU.

Stage 2 MR20DD modifications: Sports catalyst & performance exhaust, Fast road cam, fuel pump upgrades, Ported and polished head, induction kit, high flow fuel injectors.

Stage 3 MR20DD modifications: Twin charging conversions, Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Competition cam.

Mapping should help to release the full potential of all the modifications you've done to your MR20DD.

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 will rely on the modifications you've fitted and the condition of your engine.

It is the aim to any engine modification job to shove more fuel and air into your MR20DD

Air Intake manifolds transmit the air during the suck phase from the filter and allow it to be sucked into the engine and mixed with fuel.

Structure and flow rate of the Intake headers can make a large effect on to fuel engine efficiency on the MR20DD.

We often see intake headers are ripe for performance upgrades, although some car makers provide fairly well optimized intake headers.

Larger MR20DD valves, doing some 3 or 5 angle valve jobs and porting and head flowing will also lift power, this will give you a better power increase on other upgrades.

Turbo upgrades for the MR20DD

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 MR20DD

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 an engine is fitted with a turbo parts are giving better power gains and you'll see that turbo charged engines use better components.

However engines have weakspots

Discover these limits and fit better pistons and crank to handle the power.

We see many drivers spending a loads of money on turbo upgrades on the MR20DD only to suffer the humiliation of seeing the MR20DD literally blow up when it's completed.

Big turbos will usually experience low end lag, and low capacity turbos spool up really quickly but won't have the peak rpm bhp gains.

Thanks to progress the range of turbo units is always evolving and we commonly find variable vane turbo units, allowing the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

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

It is common that there is a limit in the air flow sensor AFM/MAP on the MR20DD when considerably more air is being drawn into the engine.

Going up you'll find 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 torque gains, although harder to get working. We have this feature on twinchargers if you want to read more.

Uprating MR20DD fuel injectors

You will need to ensure that the engine is not starved of fuel so will need to increase the fuelling when you start exceeding 20% of a bhp increase.Most tuners we speak with say to over specify your injector capacity.

The accepted safe increase is to add 20% capacity when fitting an injector, this takes into account injector deterioration and gives a little 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 MR20DD performance exhausts

You should look to upgrade your exhaust if the current exhaust is actually causing a restriction in flow.

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.

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

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

Problems and issues to look out for on the MR20DD

The MR20DD 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 MR20DD, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your MR20DD engine please join us in our friendly forum where you can discuss tuning options in more detail with our MR20DD 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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