Tuning Feature: Nissan VH45DE Modified

"Comprehensive guide to tuning the Nissan VH45DE engine!"

We are regularly seeing threads asking about the best VH45DE modifications. So let us look into Nissan VH45DE upgrades and outline the best mods that work on this great engine and point out some common pitfalls along the way.

TorqueCars will consider VH45DE tuning and summarise the best modifications. Nissan VH45DE offer good returns when tuned and with the right sports upgrades like remaps, turbo improvements and camshafts you will noticeably improve the drivers fun of your car.

When talking about the ultimate parts for your VH45DE engine, we are going to focus on the upgrades that give the biggest return for your cash.

Significant power hikes can be made on engines, and the VH45DE is no exception, by means of cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

NB: Fast road camshafts normally push up the torque over the rpm band, you might lose a little low down power but your higher rpm power will improve.

Race camshafts, push up the higher rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a daily driver one, ideally, should ideally to optimize your power band to your preferences.

I would be surprised if you have found a VH45DE Race cam is a pleasure to live with when driving around busy urban areas.

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

The ECU mapping and injectors and fuel pump also have an effect on the power gains you'll achieve.

A longer valve duration 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.

VH45DE Tuning Stages

Stage 1 VH45DE modifications: Intake headers, Drilled & smoothed airbox, Sports exhaust manifold, Fast road camshaft, Panel air filters, Remaps/piggy back ECU.

Stage 2 VH45DE modifications: high flow fuel injectors, Sports catalyst & performance exhaust, Ported and polished head, fuel pump upgrades, Fast road cam, induction kit.

Stage 3 VH45DE modifications: Twin charging conversions, Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Competition cam.

Mapping should help to to establish the full potential of all the parts you've done to your VH45DE.

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

Pushing air and fuel into your VH45DE is the main goal to any engine tuning project.

Intake manifold carry the air during the suck phase from the intake filter and allow it to be drawn into the engine cylinders with fuel for the squish phase.

Design and rate of flow of the Intake can make a substantial effect on to fuel engine efficiency on the VH45DE.

It's not uncommon that intake headers are in desperate need of performance upgrades, although a few makers provide reasonably good intake headers.

Big valve conversions on the VH45DE, doing some port matching and head flowing will also boost bhp, and as an added benefit will raise potential for an improved bhp increase on other tuning mods.

Turbo upgrades for the VH45DE

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 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 superb power gains.

When the engine is turbocharged, parts are relatively easy and you'll see that turbo charged engines are built using many forged and stronger components.

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

It is important to find these limits and fit forged components to utilize the power.

There are many car owners spending a lot of money on turbo charger upgrades on the VH45DE only to have the car explode when it's been completed.

Big capacity turbos commonly experience no power at low rpm, and little turbos spool up quickly but don't have the top end engines power gains.

We are pleased that the range of turbo chargers is always developing and we are seeing variable vane turbo chargers, where the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbo chargers divert the exhaust flow into 2 channels and direct these at differently angled vanes in the turbo. 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 VH45DE when considerably more air is being fed into the engine.

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

Adding a supercharger or additional turbo will make large bhp gains, although more challenging to configure. We have this in depth look at twinchargers if you want to read more.

Uprating VH45DE fuel injectors

Don't overlook the need to increase the fuel delivery when you are increasing the power - it makes the car more thirsty. We would recommend you to be generous with your injector capacity.

The rule of thumb is to add another 20% when buying an injector, which takes into account injector deterioration and gives a bit of 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 VH45DE performance exhausts

You only need to to uprate your exhaust if your current exhaust is creating a flow problem.

On most factory exhausts you'll see the flow rate is still ok even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Don't go with the widest exhaust you can find this will slow the exhaust rate - the best for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

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

Problems and issues to look out for on the VH45DE

The VH45DE 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 VH45DE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your VH45DE engine please join us in our friendly forum where you can discuss tuning options in more detail with our VH45DE owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our VH45DE guides and tips are kept up to date.

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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.

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