Tuners tips on "VH45DE Modifications"

VH45DE Modifications Guide

How to modify and upgrade the Nissan VH45DE

"Comprehensive guide to tuning the Nissan VH45DE engine!"

Sites like TorqueCars are always seeing threads about how to improve the VH45DE from people wanting to know what are the optimum VH45DE mods that work. So let us look into Nissan VH45DE parts and outline the best upgrades on this great engine and point out some problems along the way.

Now we shall examine the options for your VH45DE tuning and point out the best modifications for your car. Nissan VH45DE great bases for a tuning project and with carefully chosen motorsport upgrades like remapping, turbo kits and camshafts you will really enhance your driving experience.

When talking about the best parts for your VH45DE engine, we are going to focus on the upgrades that give the best power gain for you money.

VH45DE induction kits

Improving air intake on the VH45DE

You need air matched to fuel for an engine to work. If there is a lack of fuel then it will run lean, if there is not enough air it runs rich sapping power . 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 each cylinder is the whole point to any performance tuning job.

It is common that there is a limit in the air flow sensor MAF/MAP on the VH45DE when a lot more air is being sucked into the engine.

We see 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 flow the during the engines suck phase from the air cleaner and allow it to be sucked into the engine cylinders with fuel for the squish phase.

The shape and flow rate of the Air Intake manifolds can make a big change to fuel engine efficiency on the VH45DE.

I usually find air intake manifolds are in desperate need of aftermarket tuning parts, although a few OEM provide fairly well optimized air intake manifolds.

Increasing the VH45DE valve size, doing a bit of port matching and head flowing will also boost bhp, & importantly will give you an improved bhp increase on other mods.

VH45DE performance cam tips.

Different VH45DE engines respond better to extreme cam durations than others.

The engine timing and fuelling also have a large bearing on the torque gains you'll get.

Altering valve 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.

Significant air intake, and exhaust improvements on the VH45DE 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 bump the performance over the rpm band, you could drop a little bottom end bhp but the top end will be better.

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

A Motorsport and race cam won't do well if on the daily commute.

You should ideally optimize your bhp range to your preferences so for a car driven daily stick with a shorter duration VH45DE cam

Stage 1, 2 and 3 mods for the VH45DE

Stage 1 VH45DE parts:

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

Stage 2 VH45DE parts:

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

Stage 3 VH45DE parts:

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

The VH45DE power trains are fantastic to work on and we're pleased to see that there are quite a few choices of parts and performance parts out there.

A remap will help release the full potential of all the upgrades you've done to your VH45DE.

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 rely on the upgrades you've applied and the condition of your engine.

Turbo modifications on the VH45DE

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

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 VH45DE.

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

When your car is fitted with a turbocharger parts are simpler to install and most turbocharged engines already contain harder and stronger components.

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

We recommend you find these limitations and fit higher quality crank and pistons to cope with the power.

There are many guys spending a lots of money on turbo upgrades on the VH45DE only to suffer the humiliation of seeing the engine literally blow up on it's first outing after it's finished.

Bigger turbo chargers will usually experience a bottom end lag, and low capacity turbo chargers spool up more quickly but don't have the peak rpm bhp gains.

Over the last 20 years the choice of turbo chargers is always improving and we commonly find variable vane turbo chargers, where the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbo chargers divert the exhaust gases into a couple of channels and push these at differently angled vanes in the turbocharger. 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 performance gains, although more complex to get working. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the VH45DE

You will need to ensure that the engine is not starved of fuel so will need to increase the fuelling when you start exceeding 20% of a performance hike. It makes sense to be generous with your injectors flow rate.

The accepted safe increase is to add 20% to the flow rate when specifying an injector, helps cope with injector deterioration and allows 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 VH45DE performance exhaust upgrades

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

On most factory exhausts you'll see the flow rate is still 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 usually air flow from the engine but avoid an exhaust that is too wide or you could will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Typically exhaust restrictions are in the catalyst and filters installed, so adding a better flowing race alternative will help avoid this restriction.

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

Faults issues and things to look out for on the VH45DE

Like most engines an VH45DE, 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 VH45DE, failure to do this will exacerbate engine wear, on a tuned VH45DE 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 VH45DE why not pop over to the forums at TorqueCars where you can chat about VH45DE tuning options and read about others projects who may be planning to do similar modifications on their VH45DE.

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