Tuning Feature: Nissan QR20DE Modified

"Comprehensive guide to tuning and performance parts on the Nissan QR20DE engine!"

We often are getting posts asking about the premier QR20DE upgrades. So let us look into Nissan QR20DE mods and outline the best upgrades on this great engine and point out some potential pitfalls along the way.

The Nissan QR20DE are popular tuning projects and with carefully picked performance parts like ECU maps, turbo kits and camshafts you will dramatically maximize your driving fun.

In this article we outline options for your QR20DE tuning and outline the greatest upgrades.

Just because particular upgrades are are common on QR20DE it doesn't mean it is good, instead we will focus on the top upgrades to provide your QR20DE with the best power gain for you spend.

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

NB: Fast road camshafts usually push up the bhp across the rpm band, you could sacrifice a little low end torque but the higher rpm power will be lifted.

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

A Race cam is not great driving around busy urban areas.

You should ideally optimize your bhp range to your preferences so for a road car stick with a fast road QR20DE cam

Some QR20DE engines respond better to mild camshaft durations than others.

The ecu map and fuelling also have an effect on the torque gains you'll hit.

Altering valve durations can alter the torque 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.

QR20DE Tuning Stages

Stage 1 QR20DE modifications: Intake headers, Drilled & smoothed airbox, Fast road camshaft, Panel air filters, Remaps/piggy back ECU, Sports exhaust manifold.

Stage 2 QR20DE modifications: fuel pump upgrades, Fast road cam, Ported and polished head, Sports catalyst & performance exhaust, induction kit, high flow fuel injectors.

Stage 3 QR20DE modifications: Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Competition cam, Twin charging conversions, Internal engine upgrades (head flowing porting/bigger valves).

Mapping should help to unlock the full potential of all the upgrades you've done to your QR20DE.

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 often vary depending on the upgrades you've applied and the condition of your engine.

It is the aim to any engine tuning job to push air and fuel into the QR20DE engine

The intake plenum carry the air from the air cleaner and allow it to be drawn into the engine cylinders.

Shape and rate of flow of the Intake can make a large effect on to fuel atomisation and engine efficiency on the QR20DE.

It's not uncommon that headers are in desperate need of aftermarket parts, although a few manufacturers provide fairly well optimized headers.

Increasing the QR20DE valve size, carrying out port matching and head flowing will also boost performance, and more importantly will permit increasing the performance increase on other modifications.

Turbo upgrades for the QR20DE

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 QR20DE

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.

If the engine is turbo charged upgrades are going to net you a larger power gain and most turbocharged engines are built with uprated components.

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

Discover these limitations and install more solid crank and pistons to handle the power.

We've seen guys spending a loads of money on turbo charger upgrades on the QR20DE only to watch the QR20DE go up in smoke soon after it's used on the roads.

Larger turbos tend to experience a bottom end lag, and low capacity turbos spool up more quickly but won't have the peak end torque gains.

We are pleased that the market of turbo units is always increasing and we now see variable vane turbo units, allowing the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo units divert the exhaust flow into two channels and feed these at differently profiled vanes in the turbo charger. They also help the scavenging effect of the engine.

You'll commonly see there's a limit in the air flow sensor AFM/MAF on the QR20DE 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 power at a much lower level.

Adding a supercharger or additional turbo will make large power gains, although harder to install. We have this guide to twinchargers if you want to read more.

Uprating QR20DE fuel injectors

When you lift the bhp and torque you will need to ramp up to the fuel system.

More bhp and torque needs more fuel. We strongly recommend you to over specify your injector capacity.

The rule of thumb is to add another 20% when buying an injector, which takes into account injector deterioration and allows 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 QR20DE performance exhausts

You may need to boost your exhaust if the current exhaust is actually creating a flow problem.

On most factory exhausts you should find that your 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.

Note that with the largest exhaust you can source this will reduce the exhaust flow 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.

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

Problems and issues to look out for on the QR20DE

The QR20DE 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 QR20DE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your QR20DE engine please join us in our friendly forum where you can discuss tuning options in more detail with our QR20DE 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 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 QR20DE 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.