Tuning the Vauxhall X20XEV

"Comprehensive guide to tuning the Vauxhall X20XEV engine!"

We often are getting emails requesting info on the optimum X20XEV upgrades. So let us look into Vauxhall X20XEV upgrades and outline the best modifications on this great engine and point out some problems along the way.

The Vauxhall X20XEV are popular tuning projects and with the right mods like remapping, turbo improvements and camshafts you will definitely maximize your driving pleasure.

This pages aim is review and look at X20XEV tuning and report on the best mods that work.

Just because particular modifications are appear in lots of X20XEV projects it doesn't mean it is good, so we'll focus on the modifications that will give your X20XEV the best power gain for you spend.

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 torque gains are on offer for cam upgrades.

NB: Fast road camshafts commonly push up the performance throughout the rpm range, you could sacrifice a little low down torque but your higher rpm power will be better.

Motorsport 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.

On a typical daily driver must carefully try to match your engines power to your preferences.

I'd be amazed if you find a X20XEV Competition cam is a pleasure to live with when in heavy traffic.

Each engine responds better to more aggressive cam durations than others.

The ECU mapping and fuel pump and injectors also have a large bearing on the power gains you'll hit.

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.

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Guide to the best X20XEV tuning mods & Upgrades

  1. ECU Map Tuning & Remaps

    Some cars may require a piggyback ECU's or aftermarket ECU's to change the OEM map, but remapping is the most vital step of your tuning project to fully maximise your mods. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  2. Strengthen Your Engine

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  3. Mods that Remove a Restriction

    A restricted intake or exhaust will have an impact on your performance, so use a better flowing air filter/induction kit and better flowing exhaust (sports cats where legal are a good option) whenever your tuning creates a flow restriction. Turbo engines also benefit from intercooler upgrades as these resist heat soak for longer periods of time.

  4. Mods that Improve Fuelling

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise,  a fuel pump and injector upgrade are usual mods, but also in many cases the fuel regulator will need improvement.

  5. Mods to Provide better Airflow

    Increasing the air supply is just as essential as improving fuelling, we suggest you look at head mods (flowing and porting, 5 angle valve jobs), fit bigger valves, fast road cams and forced induction upgrades (adding a better flowing turbo) to improve air intake.

X20XEV Tuning Stages

Stage 1 X20XEV modifications: Drilled & smoothed airbox, Fast road camshaft, Sports exhaust manifold, Panel air filters, Intake headers, Remaps/piggy back ECU.

Stage 2 X20XEV modifications: Sports catalyst & performance exhaust, Ported and polished head, fuel pump upgrades, induction kit, Fast road cam, high flow fuel injectors.

Stage 3 X20XEV modifications: Twin charging conversions, Internal engine upgrades (head flowing porting/bigger valves), Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Competition cam.

The X20XEV units respond well to mods and we note that there are plenty of parts and performance parts out there.

Remaps will help to establish the full potential of all the tuning parts you've done to your X20XEV.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but the end result may depend much on the tuning parts you've done and the condition of your engine.

It is the whole point to any tuning job to feed air and fuel into the X20XEV engine

Intake take the air during the suck phase from the filter and allow it to be drawn into the engine cylinders.

The bore size, shape and flow rate of the Headers can make a noticeable effect on to fuel mixing and power on the X20XEV.

Many mass produced engine air intake manifolds are improved through motorsport parts, although a few OEM provide reasonably well designed air intake manifolds.

Big valve conversions on the X20XEV, carrying out port work and head flowing will also raise power, and as an added benefit will permit an improved power increase on other mods.

Turbo upgrades for the X20XEV

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 X20XEV

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.

When the engine is fitted with a turbocharger tuning mods are giving better power gains and you'll see that turbocharged engines are made using stronger components.

There are common areas of failure for every engine, with some being extremely strong and some just sufficiently able to handle stock power

We recommend you find these limits and install higher quality components to survive the power.

There are many people spending a a stack of money on turbo charger upgrades on the X20XEV only to experience the car catastrophically fail soon after it's been completed.

Bigger turbo chargers will usually suffer no power at low rpm, and little turbo chargers spool up much more quickly but don't have the peak end torque gains.

Over the last 20 years the selection of turbo chargers is always evolving and we commonly find variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbo chargers divert the exhaust gases into 2 channels and flow these at differently designed vanes in the turbo charger. They also boost the scavenging effect of the engine.

It is common that there is a limitation in the air flow sensor AFM/MAP on the X20XEV when a lot more air is being sucked into the engine.

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

Adding a supercharger or additional turbo will make large power gains, although more complex to install. We have this article covering twinchargers if you want to read more.

Uprating X20XEV fuel injectors

You will need to ensure that the engine is not starved of fuel so must ramp up the fuelling when you start going beyond 20% of a bhp and torque increase.We would recommend you to be generous with your injector capacity.

The accepted safe increase is to add 20% to the flow rate when buying an injector, this accounts for injector deterioration and provides a bit of spare capacity should the engine require 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 X20XEV performance exhausts

You should look to increase your exhaust if the existing exhaust is creating a restriction.

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

Please dont run with the widest exhaust you can get you'll 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 come around the catalysts installed, so adding a better flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the X20XEV

The X20XEV engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the X20XEV, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your X20XEV engine please join us in our friendly forum where you can discuss tuning options in more detail with our X20XEV owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

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 X20XEV guides and tips are kept up to date.

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