Modding and performance tuning parts for the Vauxhall C20XE engine!

All you need to know about "C20XE Modifications"

C20XE Modifications Guide

How to modify and upgrade the Vauxhall C20XE

"Comprehensive guide to tuning the Vauxhall C20XE engine!"

Our friends at TorqueCars are always getting messages about how to improve the C20XE from people inquiring about getting more power from the C20XE and wanting to know what are the best C20XE 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.

The Vauxhall C20XE offer good returns when tuned and with the optimum performance tuning mods like remaps, turbo improvements and camshafts you will really enhance your driving opportunities.

Let us review and look at C20XE tuning and show the optimum modifications.

The best C20XE upgrades on an engine are as we have found the ones that give the best power gain for your hard earned cash.

We won't be swayed by popular C20XE upgrades, they need to be cost effective.

C20XE induction kits

Improving air intake on the C20XE

You need air and fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is a lack of air it runs rich resulting in lost power and potentially damaging the engine. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the aim to any engine upgrade task to pull fuel and air into your C20XE but this has a knock on effect with the air flow sensor.

You'll commonly see there is a limit in the air flow sensor AFM/MAF on the C20XE when loads more air is being drawn into the engine.

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

Engines intake headers flow the air during the suck phase from the air filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

Design and rate of flow of the Intake headers can make a substantial difference to to fuel engine efficiency on the C20XE.

Most headers are in dire need of aftermarket parts, although a few makers provide well optimised headers.

Larger C20XE valves, getting port matching and head flowing will also lift torque, and importantly will make space for a greater torque increase on other parts.

C20XE performance cam tips.

Different C20XE engines respond better to less aggressive cam durations check your engine on a rolling road.

The map and fuel pump and injectors also have a large bearing on the bhp gains you'll get.

Altering valve durations can alter the bhp 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 C20XE can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road camshafts usually increase the bhp through the rpm range, you might lose a little low down power but your top end will be lifted.

Motorsport camshafts, increase 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 will just annoy you whilst on the daily commute.

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

Stage 1, 2 and 3 mods for the C20XE

Stage 1 C20XE parts:

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

Stage 2 C20XE parts:

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

Stage 3 C20XE parts:

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

Carefully think through your options and then buy your parts and set yourself a power target to avoid disappointment.

Remapping allows a tuner to release the full potential of all the modifications you've done to your C20XE.

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

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 figures achieved usually depend much on the modifications you've fitted and the condition of your engine.

Turbo modifications on the C20XE

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 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 significant power gains.

When your car has a turbocharger parts are relatively easy and turbo charged engines are made using many forged and stronger components.

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

We recommend you find these limits and upgrade to higher quality crank and pistons to utilize the power.

We've seen mechanics spending a loads of money on turbo upgrades on the C20XE only to have the motor throw a rod on it's first outing after it's been completed.

Big turbo chargers commonly suffer a bottom end lag, and small turbo chargers spool up really quickly but won't have the top end torque gains.

We are pleased that the market of turbo chargers is always developing and we commonly find variable vane turbo chargers, where 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 a couple of channels and flow these at differently profiled vanes in the turbocharger. They also boost the scavenging effect of the engine.

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large torque gains, although more complex to install. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the C20XE

When you increase the power you will need to pay attention to to the fuel system.

More power needs more fuel. Don't forget to over specify your injector capacity.

The accepted safe increase is to add 15% capacity when buying an injector, which takes into account injector deterioration and gives 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 C20XE performance exhaust upgrades

Only look to upgrade your exhaust system with an upgraded one is if the existing exhaust is actually causing a flow problem.

On most factory exhausts you'll see the flow rate is still ok 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 help equal out the flow of gases through the engine.

But if the exhaust is too large, ie: it's over two and a half inches diameter, you will lose much of the exhaust flow rate and end up sapping power and torque.

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

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

Faults issues and things to look out for on the C20XE

Like most engines an C20XE, 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 C20XE, failure to do this will exacerbate engine wear, on a tuned C20XE 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 C20XE why not pop over to the forums at TorqueCars where you can chat about C20XE tuning options and read about others projects who may be planning to do similar modifications on their C20XE.

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