Tuning Feature: Nissan PR25DD Modified

"Comprehensive guide to tuning the Nissan PR25DD engine!"

We are frequently seeing threads requesting information on the optimum PR25DD modifications. So let us look into Nissan PR25DD upgrades and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

Now we will review and look at PR25DD tuning and highlight the best modifications. Nissan PR25DD are good project engines and with the ultimate tuning enhancements like a remap, turbo upgrades and camshafts you will certainly improve the drivers experience of your car.

Just because particular tuning mods are are common on PR25DD it doesn't mean its worth having, instead we will concentrate on the best tuning mods to provide your PR25DD with the best power gain for you money.

Significant power gains can be made on engines, and the PR25DD is no exception, through camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road camshafts usually boost the bhp and torque across the rev band, you may lose a little bottom end torque but the top end will be higher.

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

For a typical daily driver one, ideally, must carefully try to optimize your power band to your cars usage.

I'd be gobsmaked if you have ever thought a PR25DD Motorsport and race camshaft is a pleasure to live with when in heavy traffic.

Some PR25DD engines respond better to more or less aggressive camshaft durations so view each engine as unique.

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

Altering 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.

Best PR25DD Tuning Mods & Upgrades

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PR25DD Tuning Stages

Stage 1 PR25DD modifications: Panel air filters, Drilled & smoothed airbox, Sports exhaust manifold, Remaps/piggy back ECU, Intake headers, Fast road camshaft.

Stage 2 PR25DD modifications: Sports catalyst & performance exhaust, Ported and polished head, high flow fuel injectors, Fast road cam, induction kit, fuel pump upgrades.

Stage 3 PR25DD modifications: Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Twin charging conversions, Crank and Piston upgrades to alter compression, Competition cam, Internal engine upgrades (head flowing porting/bigger valves).

Remaps helps unlock the full potential of all the upgrades you've done to your PR25DD.

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

It is the aim to any car tuning job to force more air and fuel into your PR25DD

The intake plenum flow the air during the suck phase from the filter and allow it to be pulled into the engine cylinders.

Structure and flow rate of the Air Intake manifolds can make a big change to fuel atomisation and engine efficiency on the PR25DD.

We often see headers are improved through aftermarket parts, although some OEM provide well optimised headers.

Increasing the PR25DD valve size, getting PR25DD port enlargement and head flowing will also raise power, & importantly will make space for a greater power increase on other mods.

Turbo upgrades for the PR25DD

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 PR25DD

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

When the engine is fitted with a turbocharger parts are relatively easy and turbocharged engines are built using stronger 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 upgrade to forged components to cope with the power.

It's not unheard of guys spending a lots of money on turbocharger upgrades on the PR25DD only to watch the whole thing catastrophically fail when it's used on the roads.

Bigger upgraded turbo units often experience a bottom end lag, and smaller turbo units spool up more quickly but do not have the high rpm engines power gains.

Thanks to new tech the range of turbos is always increasing and we are seeing variable vane turbos, where the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

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

It is common that there's a limitation in the air flow sensor MAP/MAF/AFM on the PR25DD when a lot 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 power at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although more complex to install. We have this feature on twinchargers if you want to read more.

Uprating PR25DD fuel injectors

When you boost the bhp and torque you will need to pay attention to to the fuelling.

More bhp and torque needs more fuel. It makes sense to be generous with your flow rate on the injectors.

The rule of thumb is to add another 20% when specifying an injector, which takes into account 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 PR25DD performance exhausts

You only need to to improve your exhaust if the existing exhaust is creating a restriction in flow.

On most factory exhausts you should find that the exhaust flow rate is ok even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Don't go with the biggest exhaust you can buy you'll slow up the exhaust flow rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Common exhaust restrictions are in the catalysts installed, so adding a better flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the PR25DD

The PR25DD 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 PR25DD, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your PR25DD engine please join us in our friendly forum where you can discuss tuning options in more detail with our PR25DD 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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We really like hearing from our readers, and hearing about which tuning parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our PR25DD guides and tips are kept up to date.

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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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