Car tuning tips:QR Modifications"

QR Modifications Guide

How to modify and upgrade the Nissan QR

"Comprehensive guide to tuning the Nissan QR engine!"

Popular tuning sites like TorqueCars often are getting posts about how to improve the QR from people inquiring about getting more power from the QR and wanting to know what are the optimum QR power upgrades. So let us look into Nissan QR tuning mods and outline the best modifications on this great engine and point out some common pitfalls along the way.

The Nissan QR are good project engines and with the right modified parts like remapping, turbo upgrades and camshafts you will definitely maximise your driving fun.

This pages aim is examine QR tuning and summarise the best upgrades.

Just because particular parts are appear in lots of QR projects it doesn't mean it is good, instead we'll focus on the best parts that will give your QR the best power gain for you spend.

Without us subscribing to the common myth of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

QR induction kits

Improving air intake on the QR

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

So Getting fuel and air into your QR is the main goal to any engine performance tuning job.

You'll commonly see there's a limit in the air flow sensor (AFM/MAF/MAP) on the QR when loads more air is being fed 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 limited bhp at a much lower level.

Intake carry the during the engines suck phase from the filter and allow it to be pulled into the engine and mixed with fuel.

Shape and flow characteristics of the Intake headers can make a large change to fuel atomisation and engine efficiency on the QR.

We often see intake are needing performance upgrades, although some car makers provide reasonably good intake.

Larger QR valves, doing some port work and head flowing will also raise torque, & importantly will permit a better torque increase on other parts.

QR performance cam tips.

Different QR engines respond better to mild cam durations than others.

The ecu map and injectors and fuel pump also will make differences on the power gains you'll achieve.

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.

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

NB: Fast road camshafts tend to increase the power through the rev range, you may lose a little low down torque but your higher rpm power will improve.

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

For a road car you must carefully try to match your engines power to your driving style.

I'd be shocked if you have found a QR Race cam is a pleasure to live with when driving in heavy traffic.

Stage 1, 2 and 3 mods for the QR

Stage 1 QR parts:

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

Stage 2 QR parts:

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

Stage 3 QR parts:

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

The QR engine blocks are fantastic to work on and we see that there are plenty of upgrades and tuning parts about.

ECU flashing will help unlock the full potential of all the tuning mods you've done to your QR.

Tuning tips and articles Engine tuning Transmission tuning Care care Intake & exhaust mods Improve handling Forums

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 will differs on the tuning mods you've fitted and the condition of your engine.

Turbo modifications on the QR

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 QR.

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

When your motor is fitted with a turbo upgrades are relatively easy and we find turbo charged engines are built using more solid components.

However you'll find engines will have power limits

Research these restrictions and upgrade to better quality crank and pistons to survive the power.

We've seen guys spending a lot of money on turbo upgrades on the QR only to suffer the indignity of watching the engine block literally blow up soon after it's been enthusiastically driven.

Large capacity turbo chargers commonly experience low end lag, and low capacity turbo chargers spool up much more quickly but don't have the peak end torque gains.

In the last 10 years the market of turbochargers is always increasing and we now see 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 flow these at differently angled vanes in the turbo. They also increase the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large torque gains, although more challenging to install. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the QR

When you increase the performance you will need to increase to the fuelling.

More performance needs more fuel. Don't forget to over specify your injectors flow rate.

As a rule of thumb add 15% when buying an injector, this takes into account injector deterioration and allows you some 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 QR performance exhaust upgrades

We'd only recommend you look to increase your exhaust system with an upgraded one is if your current exhaust is actually creating a restriction.

On most factory exhausts you'll see the flow rate is ok 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.

Note that with the largest exhaust you can get this will slow up the exhaust flow rate - the best exhausts for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

Typically exhaust restrictions are traced to the filters installed, so adding a freer flowing high performance 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 QR

Like most engines an QR, 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 QR, failure to do this will exacerbate engine wear, on a tuned QR 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 QR why not pop over to the forums at TorqueCars where you can chat about QR tuning options and read about others projects who may be planning to do similar modifications on their QR.

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