Modding uprating the Nissan VG30i engine!

Modifying and improving: "VG30i Modifications"

VG30i Modifications Guide

How to modify and upgrade the Nissan VG30i

"Comprehensive guide to performance tuning the Nissan VG30i engine!"

Popular tuning sites like TorqueCars are frequently getting emails asking about how to improve the VG30i from people wanting to know what are the best VG30i upgrades. So let us look into Nissan VG30i modifications and outline the best mods that work on this great engine and point out some potential pitfalls along the way.

The Nissan VG30i provide a fun base for your project and with the optimum uprated enhancements like remaps, turbo upgrades and camshafts you will substantially increase your driving experience.

Let us examine the options for your VG30i tuning and show the best mods that work.

Just because particular upgrades are are common on VG30i it doesn't mean it is good, so we'll concentrate on the optimum upgrades that will give your VG30i the best power gain for you money.

Without us subscribing to the popular 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'.

VG30i induction kits

Improving air intake on the VG30i

You need air matched to fuel for an engine to work. If there is too little fuel then it will run lean, if there is a lack of air it runs rich resulting in lost power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the goal to any tuning project to push air into the VG30i engine but this has a knock on effect with the air flow sensor.

You'll commonly see there's a limit in the air flow sensor MAP/MAF/AFM on the VG30i when loads more air is being pulled into the engine.

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

Air Intake manifolds transmit the on the suck phase from the air filter and allow it to be drawn into the engine cylinders.

The size of bore and shape and flow characteristics of the Plenum can make a substantial effect on to fuel atomisation and engine efficiency on the VG30i.

Many mass produced engine intake manifold are in dire need of an upgrade, although some makers provide fairly well optimized intake manifold.

Larger VG30i valves, doing some VG30i port enlargement and head flowing will also lift performance, and importantly will allow you to get an improved performance increase on other modifications.

VG30i performance cam tips.

Each engine responds better to extreme cam durations so set your engine up on a rolling road.

The map and fuelling also will say much on the bhp gains you'll get.

Extending exhaust or intake 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.

Altering your VG30i camshaft will make a dramatic difference to the engine power band. Choosing a higher performance camshaft profile raises the power band accordingly.

NB: Fast road camshafts normally boost the performance throughout the rpm range, you could sacrifice a little bottom end power but your top end will be lifted.

Race camshafts, boost the top end band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a typical daily driver you need to match your power band to your usage of the car.

You'll never find a VG30i Competition cam is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the VG30i

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 VG30i parts:

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

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

Stage 2 VG30i parts:

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

Stage 3 VG30i parts:

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

Carefully think through your options and then find your tuning parts and set yourself a power target to avoid disappointment.

ECU mapping allows a tuner to fully realize the full potential of all the tuning mods you've done to your VG30i.

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 the outcome often depend much on the tuning mods you've fitted and the condition of your engine.

Turbo modifications on the VG30i

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 VG30i.

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 an engine is fitted with a turbo modifications are going to net you a larger power gain and turbo engines will have stronger components.

There are practical limits for every engine, with some being incredibly solid and some only just able to handle stock power

Discover these restrictions and upgrade to better quality components to utilize the power.

We see many people spending a lot of money on turbo charger upgrades on the VG30i only to experience the car go up in smoke soon after it's used on the roads.

Bigger turbochargers will usually suffer a bottom end lag, and little turbochargers spool up more quickly but do not have the peak rpm bhp gains.

Over the last 20 years the market of turbo units is always developing and we commonly find variable vane turbo units, allowing the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo units divert the exhaust flow into a couple of channels and feed these at differently angled vanes in the turbo. They also increase 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 complex to get working. We have this article on twincharging if you want to read more.

Tips about fuel supply on the VG30i

Don't forget to raise the fuel system when you are increasing the bhp and torque - it makes the car more thirsty. Don't forget to over specify your flow rate on the injectors.

As a rule of thumb add 20% when fitting an injector, this accounts for injector deterioration and allows 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 VG30i performance exhaust upgrades

You should look to improve your exhaust system with an upgraded one is if your current exhaust is creating a restriction.

On most factory exhausts you'll see your 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.

Note that with the largest exhaust you can get this will slow up the exhaust flow rate - the best for power gains are usually between one and a half to two and half inches. Your exhaust design, the bend angles and construction are what have more effect on flow rates than your pipe width to a certain extent. So the exhaust design is a big factor.

The usual suspects causing problems in your exhaust flow rate come around the catalyst installed, so adding a higher flowing high 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 VG30i

Like most engines an VG30i, 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 VG30i, failure to do this will exacerbate engine wear, on a tuned VG30i 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 VG30i why not pop over to the forums at TorqueCars where you can chat about VG30i tuning options and read about others projects who may be planning to do similar modifications on their VG30i.

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