Tuning the Vauxhall X20XER

"Comprehensive guide to tuning the Vauxhall X20XER engine!"

We often are getting posts asking how to improve the X20XER from people wanting to know what are the optimum X20XER power upgrades. So let us look into Vauxhall X20XER modifications and outline the best modifications on this great engine and point out some common pitfalls along the way.

The Vauxhall X20XER are awesome to work on and with carefully chosen tuning parts like ECU maps, turbo improvements and camshafts you will really enhance your driving experience.

TorqueCars will outline options for your X20XER tuning and point out the best upgrades.

When talking about the ultimate parts for your X20XER engine, we are going to concentrate on the parts that give the best value for money.

Altering your X20XER cam will make a dramatic difference to the engine power band. Choosing a higher performance cam profile raises the power band accordingly.

NB: Fast road cams tend to raise the bhp through the rpm band, you could drop a little bottom end bhp but top end will be better.

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

A Competition cam will just annoy you whilst driving around busy urban areas.

You should ideally optimize your bhp range to your typical driving style so for a daily driver stick with a fast road X20XER cam

Some X20XER engines respond better to less aggressive camshaft durations than others.

The map and fuel pump and injectors also will say much on the power gains you'll get.

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.

X20XER Tuning Stages

Stage 1 X20XER modifications: Sports exhaust manifold, Drilled & smoothed airbox, Panel air filters, Fast road camshaft, Intake headers, Remaps/piggy back ECU.

Stage 2 X20XER modifications: Sports catalyst & performance exhaust, fuel pump upgrades, high flow fuel injectors, Fast road cam, induction kit, Ported and polished head.

Stage 3 X20XER modifications: Internal engine upgrades (head flowing porting/bigger valves), Adding or Upgrading forced induction (turbo/supercharger), Crank and Piston upgrades to alter compression, Twin charging conversions, Competition cam, Engine balancing & blueprinting.

Review your options and then find your modifications and set yourself a power target to save yourself from expensive mistakes.

Mapping should help to unlock the full potential of all the parts you've done to your X20XER.

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 may depend much on the parts you've applied and the condition of your engine.

It is the main goal to any performance tuning job to feed fuel and air into the X20XER engine

The intake plenum flow the air during the suck phase from the filter and allow it to be drawn into the engine cylinders.

Shape and rate of flow of the Intake can make a big improvement to fuel atomisation and engine efficiency on the X20XER.

Commonly we find the intake are crying out for motorsport parts, although a few OEM provide reasonably well designed intake.

Increasing the X20XER valve size, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also boost bhp and torque, and importantly will raise potential for raising the bhp and torque increase on other modifications.

Turbo upgrades for the X20XER

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 X20XER

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

If the engine has a turbo already fitted parts are relatively easy and you will discover turbo charged engines are built using strengthened components.

There are weak spots for every engine, with some being extremely strong and some only just able to handle stock power

See where you'll find these restrictions and fit better quality components to cope with the power.

There are many people spending a fortune on turbo upgrades on the X20XER only to experience the car explode on it's first outing after it's been completed.

Large turbos often suffer low end lag, and smaller turbos spool up really quickly but don't have the top end power band gains.

In the last 10 years the choice of turbo units is always moving on and we now see variable vane turbo units, allowing the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo units divert the exhaust flow into a couple of channels and direct these at differently angled vanes in the turbocharger. They also help the scavenging effect of the engine.

You'll commonly see there is a limitation in the air flow sensor AFM/MAP on the X20XER when a lot more air is being pulled into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp at a much lower level.

Adding a supercharger or additional turbo will make large performance gains, although more challenging to configure. We have this feature on twinchargers if you want to read more.

Uprating X20XER fuel injectors

You will need to ensure that the engine is not starved of fuel so must ramp up the fuelling when you start extending past 20% of a bhp and torque increase.Don't forget to be generous with your injectors flow rate.

The accepted safe increase is to add 20% when fitting an injector, this takes into account injector deterioration and allows you some 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 X20XER performance exhausts

You only need to to increase your exhaust if your exhaust is actually creating a restriction in flow.

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

Note that with the largest exhaust you can buy you'll slow up the exhaust flow 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.

Usual exhaust restrictions can be located the catalyst installed, so adding a freer flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the X20XER

The X20XER engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the X20XER, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your X20XER engine please join us in our friendly forum where you can discuss tuning options in more detail with our X20XER 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 X20XER guides and tips are kept up to date.

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