Tuning Feature: Nissan VQ40DE Modified

"Comprehensive guide to tuning the Nissan VQ40DE engine!"

We are frequently getting messages requesting info on the best tips on VQ40DE mods that work. So let us look into Nissan VQ40DE tuning mods and outline the best modifications on this great engine and point out some common pitfalls along the way.

This six cylinder V block came in many different setups over it's production run and cc ranged from two to four litres. Nissan produced a motorsport version badged as the VQ30DETT showing what this platform is capable of. Some of the 3.5 liter engines have pretty strong internals and can withstand up to 1000hp in ideal conditions, and parts from these high spec engines are often sourced and fitted into others accross the range.

Now we shall review and look at VQ40DE tuning and show the optimum upgrades. Nissan VQ40DE make awesome project engines and with the ultimate tuning tuning mods like a remap, turbo improvements and camshafts you will greatly enhance the drivers pleasure of your car.

Just because particular upgrades are appear in lots of VQ40DE projects it doesn't mean you should fit it, we will focus on the greatest upgrades to provide your VQ40DE with the best power gain for you money.

Altering your VQ40DE camshaft will make a dramatic difference to your engines power band. Choosing a higher performance camshaft profile raises the power band especially at the top end.

NB: Fast road cams tend to boost the torque throughout the rpm band, you may sacrifice a little low end power but the higher rpm power will be lifted.

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

In a car used daily one, ideally, must carefully try to match your engines power to your driving style.

I'd be shocked if you find a VQ40DE Competition cam is a pleasure to live with when driving around busy urban areas.

Each engine responds better to more or less aggressive cam durations so set your engine up on a rolling road.

The ecu map and injectors and fuel pump also have an effect on the torque gains you'll make.

Extending exhaust or intake durations 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.

VQ40DE Tuning Stages

Stage 1 VQ40DE modifications: Fast road camshaft, Panel air filters, Intake headers, Remaps/piggy back ECU, Sports exhaust manifold, Drilled & smoothed airbox.

Stage 2 VQ40DE modifications: Fast road cam, high flow fuel injectors, Ported and polished head, induction kit, fuel pump upgrades, Sports catalyst & performance exhaust.

Stage 3 VQ40DE modifications: Crank and Piston upgrades to alter compression, Twin charging conversions, Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Competition cam.

Mapping will help to establish the full potential of all the tuning mods you've done to your VQ40DE.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output may rely on the tuning mods you've fitted and the condition of your engine.

Pushing fuel and air into the VQ40DE engine is the main goal to any engine upgrade task.

Intake headers transmit the air during the suck phase from the filter and allow it to be sucked into the engine cylinders with fuel for the squish phase.

Shape and flow characteristics of the Air Intake manifolds can make a large change to fuel delivery on the VQ40DE.

On popular production engines intake manifold are begging for aftermarket tuning parts, although some makers provide reasonably well designed intake manifold.

Big valve conversions on the VQ40DE, doing a bit of port work and head flowing will also improve power, and as an added benefit will raise potential for raising the power increase on other modifications.

Turbo upgrades for the VQ40DE

NASP 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 VQ40DE

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

If an engine has forced induction parts are simpler to install and you will discover turbo charged engines are made using uprated components.

However you'll find engines will need better parts at higher power limits

It is important to find these limits and upgrade to better quality crank and pistons to survive the power.

We've seen people spending a loads of money on turbo charger upgrades on the VQ40DE only to experience the motor throw a rod soon after it's first rolling road session.

Big upgraded turbos often suffer a bottom end lag, and little turbos spool up quickly but do not have the high rpm power band gains.

Over the last 20 years the selection of turbochargers is always improving and we now see variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end performance.

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

You'll commonly see there is a limit in the air flow sensor MAP/MAF/AFM on the VQ40DE when considerably more air is being drawn into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting torque at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although more difficult to configure. We have this article covering twinchargers if you want to read more.

Uprating VQ40DE fuel injectors

When you boost the torque you will need to look at to the fuelling.

More torque needs more fuel. Don't forget to over specify your injector capacity.

The rule of thumb is to add 20% to the flow rate when fitting an injector, this accounts for injector deterioration and gives you some spare capacity should the engine need 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.

Best VQ40DE performance exhausts

You only need to to improve your exhaust if your current exhaust is actually causing a restriction.

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.

Sports exhausts will certainly help air flow out of the engine but avoid an exhaust that is too large or you may end up reduce the flow rate. Stick to 1.5 to 2.5 inches for best results.

Common exhaust restrictions can be traced to the catalysts installed, so adding a higher flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the VQ40DE

The VQ40DE engines, if regularly serviced and maintained, are generally very reliable and have few issues. {But if neglected they can cost a small fortune|When neglected they get very expensive to run|They can however be quite expensive if neglected| }

Regular oil changes are vital on the VQ40DE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your VQ40DE engine please join us in our friendly forum where you can discuss tuning options in more detail with our VQ40DE owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our VQ40DE guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

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.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.