Tuning the Vauxhall C20XE

"Comprehensive guide to tuning the Vauxhall C20XE engine!"

We are frequently seeing threads asking about the optimum C20XE power upgrades. So let us look into Vauxhall C20XE mods and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

Now we will provide a guide to C20XE tuning and outline the optimum modifications for your car. Vauxhall C20XE are popular tuning projects and with carefully picked motorsport upgrades like remapping, turbo improvements and camshafts you will really increase your driving pleasure.

When talking about the best parts for your C20XE engine, we are going to focus on the tuning parts that give the best power gain for you spend.

Altering your C20XE camshaft will make a dramatic difference to the engine torque. Choosing a higher performance camshaft profile raises the torque accordingly.

NB: Fast road cams tend to boost the power through the rpm band, you might lose a little low down power but the top end will be better.

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

A Competition camshaft won't do well if driving in heavy traffic.

You should ideally optimize your engines power to your typical driving style so for a car driven daily stick with a fast road C20XE camshaft

Each engine responds better to different camshaft durations check your engine on a rolling road.

The map and fuel pump and injectors also will say much 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.

Please watch TorqueCars Video tutorial on car tuning. And be sure to subscribe and support our new channel.

C20XE Tuning Stages

Stage 1 C20XE modifications: Intake headers, Panel air filters, Drilled & smoothed airbox, Sports exhaust manifold, Fast road camshaft, Remaps/piggy back ECU.

Stage 2 C20XE modifications: Fast road cam, high flow fuel injectors, Ported and polished head, induction kit, Sports catalyst & performance exhaust, fuel pump upgrades.

Stage 3 C20XE modifications: Adding or Upgrading forced induction (turbo/supercharger), Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Competition cam, Internal engine upgrades (head flowing porting/bigger valves), Twin charging conversions.

Remaps helps release the full potential of all the modifications you've done to your C20XE.

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

Shoving more fuel and air into the C20XE engine is vital to any engine tuning job.

Air Intake manifolds transmit the air during the suck phase from the intake filter and allow it to be drawn into the engine and mixed with fuel.

The shape and flow characteristics of the Intake can make a substantial change to fuel atomisation and engine efficiency on the C20XE.

Most air intake manifolds are improved through aftermarket parts, although a few OEM provide fairly well optimized air intake manifolds.

Fitting big valve kits, getting port matching and head flowing will also improve performance, this will allow you to get raising the performance increase on other upgrades.

Turbo upgrades for the C20XE

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 C20XE

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.

When a car is fitted with a turbo mods are going to make more power and turbo engines use harder and stronger components.

There are weak spots for every engine, with some being over specified and some just sufficiently able to handle stock power

It is important to find these limits and fit more solid crank and pistons to survive the power.

It's not unheard of tuners spending a lots of money on turbo charger upgrades on the C20XE only to watch the C20XE explode just after it's first rolling road session.

Big upgraded turbochargers will usually experience no power at low rpm, and little turbochargers spool up more quickly but do not have the top end power band gains.

Thanks to progress the market of turbochargers is always improving and we commonly find variable vane turbochargers, where the vane angle is altered according to speed to lower lag and increase top end torque.

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

It is not unusual that there's a limitation in the air flow sensor AFM/MAF on the C20XE when a lot more air is being pulled into the engine.

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

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

Uprating C20XE fuel injectors

You will need to ensure that the engine is not starved of fuel so need to increase the fuelling when you start going beyond 20% of a performance increase.We strongly recommend you to over specify your injectors flow rate.

The accepted safe increase is to add 20% to the flow rate when specifying an injector, this takes into account injector deterioration and provides 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 C20XE performance exhausts

You may need to uprate your exhaust if your exhaust is actually causing a restriction.

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

Sports exhausts generally help improve air flow out of the engine but avoid an exhaust that is too big or you may end up will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Common exhaust restrictions can be traced to the emissions filters installed, so adding a better flowing performance alternative will help avoid this restriction.

Problems and issues to look out for on the C20XE

The C20XE engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the C20XE, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your C20XE engine please join us in our friendly forum where you can discuss tuning options in more detail with our C20XE 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 tuning parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our C20XE guides and tips are kept up to date.

Please Check out my YouTube channel, we're regularly adding new content...

Click to accept YouTube Cookies & Play.

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 Vauxhall. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.