Modding uprating the Nissan QG16DE engine!

Modifying and improving: "QG16DE Modifications"

QG16DE Modifications Guide

How to modify and upgrade the Nissan QG16DE

"Comprehensive guide to performance parts and tuning the Nissan QG16DE engine!"

Forums like the one at TorqueCars are always getting messages about how to improve the QG16DE from people inquiring about getting more power from the QG16DE and wanting to know what are the best QG16DE mods that work. So let us look into Nissan QG16DE parts and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

The Nissan QG16DE are fantastic to work on and with the right sports parts like ECU maps, turbo improvements and camshafts you will really maximize your driving opportunities.

Our aim here is to examine the options for your QG16DE tuning and highlight the best upgrades.

The best QG16DE parts on an engine are as we have found the ones that give the best gains for your money.

We won't be swayed by popular QG16DE parts, they need to be cost effective.

QG16DE induction kits

Improving air intake on the QG16DE

You need fuel and air for an engine to work. If there is a lack of fuel then it will run lean, if there is a lack of air it runs rich losing power which risks damage to the QG16DE. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pulling fuel and air into each cylinder is the aim to any engine tuning task.

You'll commonly see there is a limit in the air flow sensor (AFM/MAF/MAP) on the QG16DE when loads 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.

Engines intake headers carry the during the engines suck phase from the air filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

The bore size, shape and flow rate of the Intake headers can make a substantial improvement to fuel atomisation and engine efficiency on the QG16DE.

Commonly we find the headers are in dire need of performance upgrades, although a few manufacturers provide well optimised headers.

Fitting big valve kits, carrying out 3 or 5 angle valve jobs and porting and head flowing will also boost power, and as an added benefit will afford you a better power increase on other parts.

QG16DE performance cam tips.

Different QG16DE engines respond better to less aggressive cam durations so view each engine as unique.

The map and injectors and fuel pump also have a large bearing on the torque gains you'll make.

A longer valve duration 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.

Altering your QG16DE cam will make a dramatic difference to the engine torque. Choosing a higher performance cam profile raises the torque accordingly.

NB: Fast road camshafts normally bump the power through the rpm range, you may lose a little low down bhp but your high end rpm power will be lifted.

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

For a car used daily you should ideally to optimize your bhp range to your driving style.

I'd be surprised if you find a QG16DE Competition cam is a pleasure to live with when driving in heavy traffic.

Stage 1, 2 and 3 mods for the QG16DE

Stage 1 QG16DE parts:

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

Stage 2 QG16DE parts:

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

Stage 3 QG16DE parts:

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

Carefully think through your options and then find your mods and set yourself a power target to avoid wasting your time and money.

Remapping will help fully realize the full potential of all the upgrades you've done to your QG16DE.

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 power output will depend much on the upgrades you've fitted and the condition of your engine.

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

Turbo modifications on the QG16DE

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 QG16DE.

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 an engine has a turbo already fitted tuning mods are more reliable and most turbocharged engines already contain uprated components.

There are practical limits for every engine, with some being extremely strong and some only just able to handle stock power

Research these limits and install higher quality components to cope with the power.

We see many car owners spending a fortune on turbo charger upgrades on the QG16DE only to experience the engine go up in smoke on it's first outing after it's been finished.

Larger turbos tend to suffer no power at low rpm, and low capacity turbos spool up really quickly but don't have the high rpm engines power gains.

Over the last 20 years the world of turbo chargers is always evolving and we are seeing variable vane turbo chargers, where the vane profile is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo chargers divert the exhaust gases into two channels and direct these at differently designed vanes in the turbocharger. They also improve the scavenging effect of the engine.

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

Tips about fuel supply on the QG16DE

Don't dismiss the need look at the fuel system when you are increasing the bhp and torque - it makes the car more thirsty. Care modifiers usually say to be generous with your injector capacity.

The accepted safe increase is to add another 15% when specifying an injector, this takes into account injector deterioration and gives 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 QG16DE performance exhaust upgrades

The only time you should look to increase your exhaust system with an upgraded one is if your current exhaust is actually creating a restriction in flow.

On most factory exhausts you should find that the exhaust 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 can usually air flow from the engine but avoid an exhaust that is too big or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Typically exhaust restrictions can be located the catalyst and filters installed, so adding a higher flowing high performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the QG16DE

Like most engines an QG16DE, 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 QG16DE, failure to do this will exacerbate engine wear, on a tuned QG16DE 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 QG16DE why not pop over to the forums at TorqueCars where you can chat about QG16DE tuning options and read about others projects who may be planning to do similar modifications on their QG16DE.

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