Tuning guide "X20SED Modifications"

How to modify and upgrade the Vauxhall X20SED

"Comprehensive guide to tuning the Vauxhall X20SED engine!"

Popular tuning sites like TorqueCars are always getting posts about how to improve the X20SED from people inquiring about getting more power from the X20SED and wanting to know what are the ultimate X20SED mods that work. So let us look into Vauxhall X20SED mods and outline the best modifications on this great engine and point out some frequent tuning mistakes along the way.

The Vauxhall X20SED really good project engines and with the ultimate enhancements like ECU maps, turbo upgrades and camshafts you will definitely enhance your driving fun.

Car Tuning Tips will provide a guide to X20SED tuning and highlight the ultimate mods that work.

When talking about the best parts for your X20SED engine, we are going to concentrate on the modifications that give the best power gain for you spend.

Improving air intake on the X20SED

You need air matched to fuel for an engine to work. If there is insufficient fuel then it will run lean, if there is too little air it runs rich losing power which risks damage to the X20SED. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the goal to any performance tuning job to push fuel and air into each cylinder but this has a knock on effect with the air flow sensor.

It is common that there is a restriction in the air flow sensor MAF/MAP on the X20SED when loads more air is being fed into the engine.

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

The intake plenum flow the on the suck phase from the air cleaner and allow it to be sucked into the engine cylinders.

The bore size, shape and flow characteristics of the air Intake manifold can make a substantial effect on to fuel delivery on the X20SED.

Commonly we find the air intake manifolds are needing performance upgrades, although a few manufacturers provide reasonably good air intake manifolds.

Larger X20SED valves, doing some X20SED port enlargement and head flowing will also improve torque, and as an added benefit will raise potential for increasing the torque increase on other tuning mods.

X20SED performance cam tips.

Some X20SED engines respond better to extreme camshaft durations check your engine on a rolling road.

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

Extending exhaust or intake 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 X20SED can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the bhp and power output.

NB: Fast road cams tend to increase the bhp through the rev range, you could sacrifice a little bottom end bhp but higher rpm power will be higher.

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

A Competition camshaft is not great driving in heavy traffic.

You should ideally optimize your engines power to your cars usage so for a car used daily stick with a fast road X20SED camshaft

Stage 1, 2 and 3 mods for the X20SED

Before we break the best tuning upgrades down into stages of tune, let's list the most effective tuning upgrades for you.

1. Suspension Upgrades - always improve your cars handling
2. Brake Upgrades - Even before adding power improve those brakes
3. Intake - make sure the intake is not restricted, use filters and intake upgrades to improve this
4. Exhaust - as with 3 ensure there is not restriction in the exhaust, cats are the usual bottleneck
5. Tunes - remapping, piggyback ECU's and aftermarket ECU's can all make decent gains
6. Fuelling - when you've increased power you'll need to match this with more fuel
7. Turbo upgrades - Improving the intake with a large turbo and better flowing intercooler will be the biggest power gain you'll see (but one of the most complex).

This video guide to tuning cars is a great starting point to work from in your project.

Stage 1 X20SED parts:

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

Stage 2 X20SED parts:

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

Stage 3 X20SED parts:

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

Remaps should help to unlock the full potential of all the upgrades you've done to your X20SED.

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 the outcome often rely on the upgrades you've carried out and the condition of your engine.

Turbo modifications on the X20SED

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 X20SED.

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

When an engine is turbo charged parts are relatively easy and most turbo charged engines already contain more solid components.

However engines will have power limits

Discover these limits and fit higher quality crank and pistons to cope with the power.

It's not unheard of mechanics spending a lots of money on turbocharger upgrades on the X20SED only to watch the engine go up in smoke when it's been completed.

Bigger turbo units will usually experience no power at low rpm, and low capacity turbo units spool up quickly but don't have the peak end torque gains.

Thanks to progress the selection of turbos is always increasing and we now see variable vane turbos, allowing the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbos divert the exhaust gases into two channels and feed these at differently designed vanes in the turbo. 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 power gains, although more challenging to setup. We have this article covering twinchargers if you want to read more.

Tips about fuel supply on the X20SED

Don't overlook the need to ramp up the fuel system when you are increasing the bhp - it makes the car more thirsty. Care modifiers usually say to over specify your injectors flow rate.

As a rule of thumb add 15% to the flow rate when fitting an injector, which takes into account injector deterioration and gives you some spare capacity should the engine need 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 X20SED performance exhaust upgrades

The only time you should look to improve your exhaust system with an upgraded one is if the current exhaust is actually causing a restriction in flow.

On most factory exhausts you'll find the exhaust 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 will certainly help air flow out of the engine but do not go too wide or you may end up will reduce the flow rate. Stick to one and a half to two and half inches for best results.

The usual suspects causing problems in your exhaust flow rate come around the catalyst and filters installed, so adding a higher flowing race alternative will help avoid this restriction.

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

Faults issues and things to look out for on the X20SED

Like most engines an X20SED, 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 X20SED, failure to do this will exacerbate engine wear, on a tuned X20SED 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 X20SED why not pop over to the forums at TorqueCars where you can chat about X20SED tuning options and read about others projects who may be planning to do similar modifications on their X20SED.

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

We want to know your experiences with upgrades on your X20SED, it helps us improve our tips and keeps us current so please use the comments box to drop a tip.

This entry was posted under Makes and Models. Tags: engine, 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.

Check out TorqueCars new YouTube channel, and see their awesome new content...