Nissan QG15DE Tuning

"All you need to know about tuning the Nissan QG15DE engine!"

The Nissan QG15DE is a smaller displacement member of the QG engine family, introduced in the late 1990s and early 2000s. This 1.5-liter inline-four engine is celebrated for its balance of efficiency and performance, particularly in compact and subcompact vehicles where engine weight to power output is a factor.

The QG15DE illustrates Nissan's commitment to providing reliable and economical engine options for a global market.

We shall detail the best approach to QG15DE tuning and show the optimum mods that work. Nissan QG15DE are popular engines and as this was fitted to lighter small cars, it proved quite popular. So let's see what tuning options there are for this engine.

We are going to be brutally honest, primarily so we don't raise your hopes too much. I've spent more than I should modifying a car and if I knew what the power gains were I would have done something else.

So this is quite a small engine at 1.5 liters, and was build for reliability rather than performance. Right from the outset I should point out that power gains will be minimal, so you should focus on improving the handling and making the car more fun to drive.

For those that love tuning and tinkering we'll go into the common mods for this engine and see what's possible.

History, Power & Specs of the QG15DE Engine

2000 to 2006 this was fitted to the Almera, and Sunny but also appeared in A Renault model. It replaced the GA15DE

Typically, the QG15DE produces about 90 to 105 horsepower and around 105 to 110 lb-ft of torque. While these figures might not suggest high performance, the engine is optimized for efficiency and reliability, making it well-suited for urban driving and daily commuting.

• 90 hp at 5,600 rpm 128 Nm 94 lbft at 2,800 rpm
• 98 hp at 6,000 rpm 136 Nm 100 lbft at 4,000 rpm
• 105 hp at 6,000 rpm 135 Nm 100 lbft at 4,000 rpm
• 109 hp at 6,000 rpm 143 Nm 105 lbft at 4,000 rpm

Tuning the Nissan QG15DE and best QG15DE performance parts.

Best QG15DE upgrades

When talking about the top modifications for your QG15DE engine, we are going to concentrate on the mods that give the best power gain for your money.

It operates with a DOHC (Dual Overhead Camshaft) design and has four valves per cylinder, which improves the engine's ability to breathe and perform efficiently at various speeds.

Performance camshafts work better at higher RPM, but we've always seen top-end power gains through performance camshafts on most engines.

Useful gains on the QG15DE can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

Fast road cams usually push up the bhp and torque across the rev band, you might in some instances lose a little bottom end bhp but high end rpm power will be better.

Sourcing a cam for this engine is quite a challenge, a few companies will offer a regrind on your stock cam to improve performance, but I really don't feel that the gains are worth it.

Typically a race cams, push up the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

On a car used daily you need to match your engines power to your driving style.

I'd be amazed if you think that a QG15DE Motorsport cam is a pleasure to live with when driving in heavy traffic. The low end idle will be very lumpy and irregular, so something you would notice on a track when you drive in the upper third of the rpm band, but on roads this is a serious issue and we've heard from lots of drivers lamenting their decision to add an extreme competition cam profile to their engine.

Some QG15DE engines respond better to more or less aggressive camshaft durations so view each engine as unique.

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

Bear in mind that to get a tune/remap on this you'll need an aftermarket ECU, Megasquirt and Apexi Power FC are two that our Nissan guys are talking about.

A set of new exhaust headers with a high flow cat will help raise the power as well, and with all the other mods you'll see around 10hp more, not much for your outlay. Bigger gains come from extensive engine work.

A longer valve duration can alter the bhp 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.

Please watch our video which covers the 5 principles of tuning your car. Be sure to keep up with our latest YouTube content and subscribe.

Best Engine Mods for your car

1. 1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
   2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
   3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
   4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
   5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.

Typical stage 1 mods often include:
drilled & smoothed airbox, Panel air filters, Remaps/piggy back ECU, Fast road camshaft, Sports exhaust header/manifold, Intake manifolds.

Typical stage 2 mods often include:
Ported and polished head, Fast road cam, induction kit, high flow fuel injectors, fuel pump upgrades, Sports catalyst & performance exhaust.

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

It is the aim to any engine tuning job to force air into each cylinder

The intake manifolds take the air during the suck phase from the filter and allow it to be sucked into the engine and mixed with fuel.

The design and flow characteristics of the Intake manifold can make a substantial difference to fuel engine efficiency on the QG15DE.

We often see plenum chambers are crying out for a performance upgrade, although some manufacturers provide well optimized plenum chambers.

Increasing the QG15DE valve size, doing a bit of port matching, and head flowing will also lift bhp and torque, and as an added benefit will raise the potential for a greater bhp and torque increase on other parts. Even with these mods you'll only be looking at a few more bhp.

Are QG15DE Turbo upgrades worth it?

NA (naturally aspirated) 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 QG15DE.

We don't recommend you try to add a turbo to this engine, the cost and work involve would be too great, especially considering you could do an engine swap for less money and save yourself a lot of time.

That said it is not impossible, but engine swaps make so much more economic sense here.

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.

When your motor is turbo charged parts are more reliable and we find turbo engines will have many forged and stronger components.

There are practical limits for every engine, with some being very over-engineered and some only able to handle stock power, discover these restrictions and fit better quality components to utilize the power.

We see many tuners spending loads on turbocharger upgrades on engines like the QG15DE only to suffer the indignity of watching the whole thing catastrophically fail just after its first rolling road session.

Adding a supercharger or additional turbo will make large bhp and torque gains, although more complex to configure. We have this guide to twinchargers if you want to read more.

Fuelling

Don't dismiss the need ramp up the fuelling when you are increasing the bhp - it makes the car more thirsty. Don't forget to be generous with your injector capacity.

The accepted safe increase is to add another 20% when specifying an injector, this takes into account injector deterioration and gives a bit of spare capacity should the engine require 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.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58psi of fuel pressure at idle.

4 Cylinder NA (naturally aspirated) engines

1. 1. • 58 PSI 285cc/min 200hp
      • 58 PSI 426cc/min 300hp

QG15DE Performance Exhausts

You may need to improve your exhaust if your exhaust is creating a restriction in flow.

Replacing the exhaust headers will improve the engine note, and give you a little more power, throw in a full exhaust system and you get a nice growl from the QG15DE, but it is questionable if you will notice the extra power, but I'm sure you'll have a lot more fun.

On most factory exhausts you'll see the flow rate is still fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Do not go with the largest exhaust you can find you'll slow up the exhaust flow rate - the best for power gains are usually between 1.3 to 2.0 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions are in the catalyst and filters installed, so adding a higher flowing performance catalyst removes the restriction. We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars.

Weak spots, Issues & problem areas on the QG15DE

The QG15DE engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

High fuel consumption is a common issue, and may indicate problems.

Regular maintenance tasks such as oil changes, spark plug replacement, and timing chain checks are crucial for keeping the engine in good working condition. The timing chain, in particular, should be monitored for any signs of wear or noise, as it drives the camshafts and is critical to the engine's operation.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the QG15DE, especially when tuned, and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your QG15DE engine please join us in our friendly forum where you can discuss with our QG15DE owners.

It would also be worth reading our unbiased articles to get a full grasp of the benefits and drawbacks
of each modification.

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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.

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