Car tuning tips:VG20E Modifications"

How to modify and upgrade the Nissan VG20E

"Comprehensive guide to tuning the Nissan VG20E engine!"

Popular tuning sites like TorqueCars are regularly getting emails asking about how to improve the VG20E from people wanting to know what are the best tips on VG20E mods that work. So let us look into Nissan VG20E upgrades and outline the best mods that work on this great engine and point out some common pitfalls along the way.

The Nissan VG20E make awesome project engines and with the optimum uprated upgrades like remaps, turbo upgrades and camshafts you will certainly maximize your driving enjoyment.

Car Tuning Tips will review VG20E tuning and highlight the premier modifications.

Just because particular upgrades are are common on VG20E it doesn't mean you should fit it, instead we'll concentrate on the best upgrades that will give your VG20E the biggest power gain return for your cash.

Without us subscribing to the mentality of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

Improving air intake on the VG20E

You need air and fuel for an engine to work. If there is insufficient 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 the aim to any engine modification project to force fuel and air into each cylinder but this has a knock on effect with the air flow sensor.

It is common that there is a limit in the air flow sensor AFM/MAP on the VG20E when considerably more air is being fed 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 torque at a much lower level.

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

The shape and flow rate of the Air Intake manifolds can make a large difference to to fuel engine efficiency on the VG20E.

It's not uncommon that headers are ripe for a performance upgrade, although a few car makers provide decently flowing headers.

Increasing the VG20E valve size, carrying out VG20E port enlargement and head flowing will also lift bhp, the fantastic side effect is it will permit raising the bhp increase on other parts.

VG20E performance cam tips.

Some VG20E engines respond better to different camshaft durations so view each engine as unique.

The engine timing and fuel pump and injectors also will make differences on the power gains you'll achieve.

Extending exhaust or intake durations 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.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen cam profile, so large bhp gains are on offer for cam upgrades.

NB: Fast road cams commonly push up the performance over the rpm band, you may lose a little low down torque but top end will be better.

Competition cams, push up the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

A Competition cam makes it harder when in heavy traffic.

You should ideally match your engines power to your usage of the car so for a road car stick with a mild fast road VG20E cam

Stage 1, 2 and 3 mods for the VG20E

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 VG20E parts:

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

Stage 2 VG20E parts:

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

Stage 3 VG20E parts:

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

ECU mapping will help release the full potential of all the modifications you've done to your VG20E.

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 usually depend much on the modifications you've carried out and the condition of your engine.

Turbo modifications on the VG20E

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 VG20E.

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 your motor is turbocharged, parts are relatively easy and you'll see that turbocharged engines will have uprated components.

However you will find an engines will have power limits

Research these restrictions and install higher quality crank and pistons to cope with the power.

There are many people spending a a stack of money on turbocharger upgrades on the VG20E only to suffer the humiliation of seeing the engine block catastrophically fail just after it's been completed.

Larger turbos often experience a bottom end lag, and low capacity turbos spool up quickly but do not have the peak rpm engines power gains.

In the last 10 years the world of turbos is always moving on and we are seeing variable vane turbos, allowing the vane profile is altered according to speed to lower lag and increase top end torque.

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

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

Tips about fuel supply on the VG20E

Don't miss you'll need to boost the fuel delivery when you are increasing the bhp - it makes the car more thirsty. At this point we flag up the need to over specify your flow rate on the injectors.

The rule of thumb is to add 15% to the flow rate when fitting an injector, this allows for injector deterioration and allows 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 VG20E performance exhaust upgrades

Only look to improve your exhaust system with an upgraded one is if your current exhaust is actually causing a restriction.

On most factory exhausts you'll find the flow rate is fine 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 help balance the flow of air through the engine.

But if the exhaust pipe is too large, ie: it's over two and a half inches diameter, you will lose a great deal of the exhaust flow rate and end up sapping power and torque.

The usual suspects causing problems in your exhaust flow rate can be traced to the filters installed, so adding a better flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the VG20E

Like most engines an VG20E, 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 VG20E, failure to do this will exacerbate engine wear, on a tuned VG20E 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 VG20E why not pop over to the forums at TorqueCars where you can chat about VG20E tuning options and read about others projects who may be planning to do similar modifications on their VG20E.

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This entry was posted under Makes and Models. Tags: engine, nissan
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