Modding uprating the Nissan VQ20DE engine!

Explore VQ20DE Modifications"

How to modify and upgrade the Nissan VQ20DE

"Comprehensive guide to tuning the Nissan VQ20DE engine!"

Popular tuning sites like TorqueCars often are getting messages asking about how to improve the VQ20DE from people wanting to know what are the best tips for VQ20DE mods that work. So let us look into Nissan VQ20DE mods and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

The Nissan VQ20DE provide a fun base for your project and with carefully chosen performance parts like remaps, turbo upgrades and camshafts you will positively maximise your driving pleasure.

This pages aim is examine the options for your VQ20DE tuning and point out the ultimate upgrades.

The best VQ20DE parts on an engine are usually the ones that give the biggest return for your money.

We won't be swayed by popular VQ20DE parts, they need to be cost effective.

VQ20DE induction kits

Improving air intake on the VQ20DE

You need air and fuel 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 and potentially damaging the engine. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Forcing fuel and air into the VQ20DE engine is the aim to any tuning project.

You'll commonly see there is a limitation in the air flow sensor MAF/MAP on the VQ20DE when considerably more air is being fed into the engine.

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

Intake headers flow the during the engines suck phase from the filter and allow it to be drawn into the engine cylinders.

The size of bore and shape and rate of flow of the Headers can make a big difference to to fuel delivery on the VQ20DE.

We often see intake manifold are ripe for performance upgrades, although a few manufacturers provide well optimised intake manifold.

Big valve conversions on the VQ20DE, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also increase bhp and torque, and as an added benefit will allow you to get a greater bhp and torque increase on other tuning mods.

VQ20DE performance cam tips.

Each engine responds better to less aggressive camshaft durations than others.

The map and injectors and fuel pump also will say much on the bhp gains you'll hit.

Altering valve durations 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.

Significant air intake, and exhaust improvements on the VQ20DE can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

NB: Fast road cams tend to boost the power across the rev range, you may sacrifice a little bottom end power but high end rpm power will be lifted.

Motorsport and race cams, boost 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 engines power to your usage of the car.

You'll never find a VQ20DE Race cam is a pleasure to live with when driving in heavy traffic.

Stage 1, 2 and 3 mods for the VQ20DE

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

  1. Suspension Upgrades - always improve your cars handling
  2. Brake Upgrades - Even before adding power improve those brakes
  3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
  4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
  5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
  6. Fuelling - when you've increased power you'll need to match this with more fuel
  7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 VQ20DE parts:

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

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

Stage 2 VQ20DE parts:

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

Stage 3 VQ20DE parts:

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

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

Remaps allows a tuner to release the full potential of all the upgrades you've done to your VQ20DE.

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 mileage may rely on the upgrades you've carried out and the condition of your engine.

Turbo modifications on the VQ20DE

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 VQ20DE.

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

If an engine is fitted with a turbocharger modifications are relatively easy and most turbo charged engines are built with stronger components.

However engines will need better parts at higher power limits

Research these limits and upgrade to more solid crank and pistons to survive the power.

We've seen car owners spending a a stack of money on turbo charger upgrades on the VQ20DE only to watch the motor explode soon after it's finished.

Big upgraded turbo units will usually experience no power at low rpm, and smaller turbo units spool up really quickly but do not have the high rpm bhp gains.

We are pleased that the selection of turbo chargers is always increasing and we commonly find variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end performance.

Twin scroll turbo chargers divert the exhaust gases into 2 channels and feed 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 difficult to install. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the VQ20DE

When you improve the performance you will need to uprate to the fuel delivery.

More performance needs more fuel. Experienced tuners recommend to over specify your flow rate on the injectors.

As a rule of thumb add another 15% when fitting an injector, helps cope with injector deterioration and provides 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 VQ20DE performance exhaust upgrades

Only look to increase your exhaust system with an upgraded one is if your exhaust is creating a flow problem.

On most factory exhausts you'll see the 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 do not go too wide or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

The usual suspects causing problems in your exhaust flow rate can be located the catalysts installed, so adding a higher flowing race 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 VQ20DE

Like most engines an VQ20DE, 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 VQ20DE, failure to do this will exacerbate engine wear, on a tuned VQ20DE 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 VQ20DE why not pop over to the forums at TorqueCars where you can chat about VQ20DE tuning options and read about others projects who may be planning to do similar modifications on their VQ20DE.

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