Tuning guide "QR20DE Modifications"

How to modify and upgrade the Nissan QR20DE

"Comprehensive guide to performance tuning the Nissan QR20DE engine!"

Sites like TorqueCars often are getting messages requesting information on how to improve the QR20DE from people wanting to know what are the best tips on QR20DE power upgrades. So let us look into Nissan QR20DE tuning mods and outline the best mods that work on this great engine and point out some problems along the way.

Now we will provide a guide to QR20DE tuning and highlight the best modifications. Nissan QR20DE are good project engines and with the ultimate enhancements like remapping, turbo improvements and camshafts you will greatly maximize your driving fun.

The best QR20DE tuning parts on an engine are sensibly the ones that give the best gains for your money.

We won't be swayed by popular QR20DE tuning parts, they need to be cost effective.

Improving air intake on the QR20DE

You need air matched to fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is too little air it runs rich resulting in lost power which risks damage to the QR20DE. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pulling air into each cylinder is the main goal to any engine upgrade job.

You'll commonly see there is a limit in the air flow sensor MAF/MAP on the QR20DE when a lot more air is being drawn into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Air Intake manifolds carry the during the engines suck phase from the intake filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

Shape and rate of flow of the air Intake manifold can make a large change to fuel engine efficiency on the QR20DE.

We often see headers are needing aftermarket parts, although a few makers provide well optimised headers.

Adding a QR20DE larger valve kit, getting QR20DE port enlargement and head flowing will also raise bhp, & importantly will afford you an improved bhp increase on other parts.

QR20DE performance cam tips.

Some QR20DE engines respond better to more or less aggressive cam durations check your engine on a rolling road.

The ECU mapping and fuelling also will make differences on the power gains you'll get.

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.

Altering your QR20DE camshaft will make a dramatic difference to the engine torque. Choosing a higher performance camshaft profile raises the torque accordingly.

NB: Fast road cams normally raise the bhp through the rpm band, you might lose a little low down power but top end will improve.

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

For a daily driver you should ideally to match your torque band to your typical driving style.

I'd be shocked if you find a QR20DE Motorsport and race camshaft is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the QR20DE

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

1. Suspension Upgrades - always improve your cars handling
2. Brake Upgrades - Even before adding power improve those brakes
3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
6. Fuelling - when you've increased power you'll need to match this with more fuel
7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 QR20DE parts:

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

Stage 2 QR20DE parts:

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

Stage 3 QR20DE parts:

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

Remapping should help to to establish the full potential of all the parts you've done to your QR20DE.

You will typically expect to see gains of approximately 20-30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the end result often depend much on the parts you've fitted and the condition of your engine.

Turbo modifications on the QR20DE

To get a turbo working on a NASP engine there is a lot involved, from lowering compression ratio to improved fuel supply and mapping, so we have found a great guide to helpavoid the common pitfalls or end up with an unfinished project because you were not told what you were getting into by doing this on the 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 massive power gains.

If an engine has a turbocharger tuning mods are going to make more power and you'll see that turbo charged engines are made using harder and stronger components.

There are weak spots for every engine, with some being very over engineered and some only just able to handle stock power

We recommend you find these restrictions and fit forged components to cope with the power.

There are many tuners spending a fortune on turbocharger upgrades on the QR20DE only to have the car literally blow up on it's first outing after it's first rolling road session.

Larger turbos will usually experience a bottom end lag, and smaller turbos spool up really quickly but don't have the peak rpm bhp gains.

We are pleased that the world of turbochargers is always improving and we are seeing variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbochargers divert the exhaust gases into 2 channels and feed these at differently profiled vanes in the turbo. They also boost the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp and torque gains, although more complex to get working. We have this article on twincharging if you want to read more.

Tips about fuel supply on the QR20DE

You will need to ensure that the engine is not starved of fuel so will have to ramp up the fuelling when you start going beyond 20% of a bhp and torque hike. At this point we flag up the need to be generous with your injector capacity.

The accepted safe increase is to add another 20% when buying an injector, this allows for injector deterioration and affords a little spare capacity should the engine require more fuel.

Don't forget that different fuel grades will usually require different settings, a high octane fuel will burn more efficiently than lower octane fuel for example. A car will trim fuel supply to keep within the ideal air fuel mix but at the extreme ends you may need to adjust your injector capacity, or the mapping or you'll get flat spots and potential lean or rich fuel issues..

Recommended QR20DE performance exhaust upgrades

The only time you should look to uprate your exhaust system with an upgraded one is if your current exhaust is creating a flow problem.

On most factory exhausts you'll see the flow rate is still good even on modest power gains, but on a serious tuning project with a big boost in power you will certainly need to get a better flowing exhaust.

Sports exhausts will certainly help air flow out of the engine but do not go too large or you may end up will reduce the flow rate. Stick to one and a half to two and half inches for best results.

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

Catalyst removal (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the QR20DE

Like most engines an QR20DE, should have few issues if it gets properly serviced and looked after.

We cannot stress enough the need for oil changes with the correct grade of oil on the QR20DE, failure to do this will exacerbate engine wear, on a tuned QR20DE this is more important than ever and close attention should be paid to your maintenance schedule.

If you are interested in learning more or getting impartial tuning advice for your QR20DE why not pop over to the forums at TorqueCars where you can chat about QR20DE tuning options and read about others projects who may be planning to do similar modifications on their QR20DE.

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This entry was posted under Makes and Models. Tags: engine, nissan
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