Modifying and improving: "QG16DE Modifications"

QG16DE Modifications Guide

How to modify and upgrade the Nissan QG16DE

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

Popular tuning sites like TorqueCars are regularly getting emails asking about how to improve the QG16DE from people inquiring about getting more power from the QG16DE and wanting to know what are the optimum QG16DE upgrades. So let us look into Nissan QG16DE mods and outline the best modifications on this great engine and point out some problems along the way.

The Nissan QG16DE are popular tuning projects and with carefully picked motorsport modifications like a remap, turbo kits and camshafts you will greatly increase your driving opportunities.

This pages aim is detail the best approach to QG16DE tuning and highlight the optimum mods that work.

When talking about the top parts for your QG16DE engine, we are going to focus on the upgrades that give the biggest return for your cash.

QG16DE induction kits

Improving air intake on the QG16DE

You need fuel and air for an engine to work. If there is not enough fuel then it will run lean, if there is not enough 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 Getting air into each cylinder is the main goal to any engine modification project.

You'll commonly see there's a limit in the air flow sensor MAP/MAF/AFM on the QG16DE when loads more air is being fed into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited bhp and torque at a much lower level.

Intake manifolds transmit the during the engines suck phase from the filter and allow it to be fed into the engine cylinders.

The shape and flow characteristics of the Headers can make a big improvement to fuel atomisation and engine efficiency on the QG16DE.

Commonly we find the intake headers are in dire need of motorsport parts, although some makers provide reasonably well designed intake headers.

Increasing the QG16DE valve size, doing a bit of port matching and head flowing will also improve bhp and torque, & importantly will give you a better bhp and torque increase on other upgrades.

QG16DE performance cam tips.

Each engine responds better to different cam durations than others.

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

A longer valve duration 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 QG16DE cam will make a dramatic difference to the engine bhp. Choosing a higher performance cam profile raises the bhp accordingly.

NB: Fast road camshafts usually increase the bhp over the rev band, you might lose a little bottom end bhp but your high end rpm power will be lifted.

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

A Motorsport and race camshaft won't do well if in heavy traffic.

You should ideally optimize your torque band to your driving style so for a daily driver stick with a mild fast road QG16DE camshaft

Stage 1, 2 and 3 mods for the QG16DE

Stage 1 QG16DE parts:

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

Stage 2 QG16DE parts:

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

Stage 3 QG16DE parts:

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

Plan your options and then acquire your tuning mods and set yourself a power target to save yourself from expensive mistakes.

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

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 your results will rely on the mods you've fitted and the condition of your engine.

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 massive power gains.

If your car has a turbocharger parts are more reliable and most turbo engines are made using strengthened components.

However you'll find engines have limits

We recommend you find these restrictions and upgrade to higher quality crank and pistons to survive the power.

We see many people spending a loads on turbo upgrades on the QG16DE only to see the engine literally blow up on it's first outing after it's been completed.

Big upgraded turbo units will usually experience a bottom end lag, and smaller turbo units spool up quickly but do not have the top end bhp gains.

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

Twin scroll turbos divert the exhaust flow into 2 channels and push these at differently profiled vanes in the turbo. 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 bhp gains, although more challenging to get working. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the QG16DE

When you improve the performance you will need to uprate to the fuelling.

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

The rule of thumb is to add 20% when fitting an injector, this allows for injector deterioration and gives 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 QG16DE performance exhaust upgrades

Only look to upgrade your exhaust system with an upgraded one is if the existing exhaust is actually creating a flow problem.

On most factory exhausts you'll see your 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.

Sports exhausts equal out the flow of gases through the engine.

But if the exhaust pipe is too big, ie: over two and a half inches diameter, you will lose a lot of your flow rate and end up sapping power and torque.

Usual exhaust restrictions are traced to the catalyst and filters installed, so adding a faster flowing race alternative will help avoid this restriction.

Decat pipes (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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