Modding upgrading and tuning the Vauxhall Z22XE engine!

Tuning guide "Z22XE Modifications"

Z22XE Modifications Guide

How to modify and upgrade the Vauxhall Z22XE

"Comprehensive guide to tuning the Vauxhall Z22XE engine!"

TorqueCars are always getting messages about how to improve the Z22XE from people inquiring about getting more power from the Z22XE and wanting to know what are the best tips for Z22XE upgrades. So let us look into Vauxhall Z22XE upgrades and outline the best modifications on this great engine and point out some common pitfalls along the way.

The Vauxhall Z22XE have loads of potential and with a few sensible sports parts like remapping, turbo improvements and camshafts you will dramatically enhance your driving enjoyment.

We shall examine Z22XE tuning and summarise the greatest modifications for your car.

The best Z22XE 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 Z22XE upgrades, they need to be cost effective.

Z22XE induction kits

Improving air intake on the Z22XE

You need air matched to fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is not enough 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 Feeding more air into your Z22XE is the primary aim to any engine modification task.

You'll commonly see there's a limit in the air flow sensor MAF/MAP on the Z22XE when considerably more air is being pulled into the engine.

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

Engines intake headers take the air during the suck phase from the intake filter and allow it to be sucked into the engine and mixed with fuel.

The bore size, shape and rate of flow of the air Intake manifold can make a noticeable effect on to fuel engine efficiency on the Z22XE.

I usually find intake headers are in desperate need of aftermarket parts, although some manufacturers provide decently flowing intake headers.

Larger Z22XE valves, getting port work and head flowing will also improve torque, and as an added benefit will afford you increasing the torque increase on other tuning parts.

Z22XE performance cam tips.

Some Z22XE engines respond better to mild camshaft durations check your engine on a rolling road.

The engine timing and fuelling also have a large bearing on the power gains you'll achieve.

Extending exhaust or intake durations 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.

Significant air intake, and exhaust improvements on the Z22XE can be made from cam upgrades. Changing the cam profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

NB: Fast road cams tend to increase the power throughout the rev band, you may sacrifice a little low end power but the higher rpm power will be better.

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

On a daily driver you need to match your bhp range to your usage of the car.

I would be surprised if you have found a Z22XE Race camshaft is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the Z22XE

Stage 1 Z22XE parts:

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

Stage 2 Z22XE parts:

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

Stage 3 Z22XE parts:

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

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

ECU mapping allows a tuner to fully realize the full potential of all the mods you've done to your Z22XE.

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 often differs on the mods you've fitted and the condition of your engine.

Turbo modifications on the Z22XE

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 Z22XE.

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

If your car is fitted with a turbo parts are going to net you a larger power gain and you will discover turbo engines already contain harder and stronger components.

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

It is important to find these limits and install forged components to handle the power.

We see many drivers spending a loads of money on turbo upgrades on the Z22XE only to watch the engine catastrophically fail just after it's completed.

Big capacity turbochargers commonly experience low end lag, and low capacity turbochargers spool up much more quickly but do not have the top end power band gains.

Thankfully the selection of turbochargers is always evolving and we are seeing variable vane turbochargers, where the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbochargers divert the exhaust gases into two channels and flow these at differently profiled 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 install. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the Z22XE

When you lift the bhp you will need to pay attention to to the fuelling.

More bhp needs more fuel. Most tuners we speak with say to be generous with your flow rate on the injectors.

The accepted safe increase is to add 15% capacity when fitting an injector, this takes into account injector deterioration and provides a little 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 Z22XE performance exhaust upgrades

You should look to boost your exhaust system with an upgraded one is if the existing exhaust is actually creating a restriction in flow.

On most factory exhausts you'll find your flow rate is good 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 usually air flow through the engine but do not go too big or you may end up will reduce the flow rate. Stick to one and a half to two and half inches for best results.

Typically exhaust restrictions are traced to the emissions filters installed, so adding a freer flowing sports alternative will help avoid this restriction.

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

Faults issues and things to look out for on the Z22XE

Like most engines an Z22XE, 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 Z22XE, failure to do this will exacerbate engine wear, on a tuned Z22XE 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 Z22XE why not pop over to the forums at TorqueCars where you can chat about Z22XE tuning options and read about others projects who may be planning to do similar modifications on their Z22XE.

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