Tuning the Vauxhall Z24XE FlexPower

"Comprehensive guide to tuning the Vauxhall Z24XE FlexPower engine!"

We often are getting emails about the ultimate Z24XE FlexPower power upgrades. So let us look into Vauxhall Z24XE FlexPower parts and outline the best upgrades on this great engine and point out some problems along the way.

The Vauxhall Z24XE FlexPower make awesome project engines and with the optimum tuning upgrades like remaps, turbo improvements and camshafts you will positively maximize your driving experience.

TorqueCars will review and look at Z24XE FlexPower tuning and summarise the best upgrades.

When talking about the ultimate parts for your Z24XE FlexPower engine, we are going to focus on the upgrades that give the best power gain for you spend.

Significant gains on the Z24XE FlexPower can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

NB: Fast road camshafts usually bump the bhp throughout the rev range, you may sacrifice a little bottom end power but higher rpm power will improve.

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

In a car driven daily you need to match your power band to your cars usage.

I'd never have found a Z24XE FlexPower Motorsport and race camshaft is a pleasure to live with when driving around busy urban areas.

Different Z24XE FlexPower engines respond better to more aggressive camshaft durations so view each engine as unique.

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

Longer 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.

Z24XE FlexPower Tuning Stages

Stage 1 Z24XE FlexPower modifications: Intake headers, Sports exhaust manifold, Fast road camshaft, Panel air filters, Drilled & smoothed airbox, Remaps/piggy back ECU.

Stage 2 Z24XE FlexPower modifications: Fast road cam, induction kit, high flow fuel injectors, fuel pump upgrades, Ported and polished head, Sports catalyst & performance exhaust.

Stage 3 Z24XE FlexPower modifications: Crank and Piston upgrades to alter compression, Internal engine upgrades (head flowing porting/bigger valves), Adding or Upgrading forced induction (turbo/supercharger), Competition cam, Engine balancing & blueprinting, Twin charging conversions.

ECU mapping allows a tuner to fully realize the full potential of all the mods you've done to your Z24XE FlexPower.

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

Feeding fuel and air into each cylinder is the main goal to any performance tuning task.

Intake manifold take the air during the suck phase from the intake filter and allow it to be pulled into the engine cylinders.

Shape and flow characteristics of the Intake can make a large change to fuel engine efficiency on the Z24XE FlexPower.

It's not uncommon that intake are ripe for performance upgrades, although some makers provide decently flowing intake.

Big valve conversions on the Z24XE FlexPower, doing some Z24XE FlexPower port enlargement and head flowing will also raise bhp, and significantly will permit raising the bhp increase on other parts.

Turbo upgrades for the Z24XE FlexPower

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 Z24XE FlexPower

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

When your car is fitted with a turbo upgrades are simpler to install and you'll see that turbocharged engines will have uprated components.

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

Research these restrictions and install better quality components to utilize the power.

We see many people spending a loads on turbo charger upgrades on the Z24XE FlexPower only to experience the motor explode when it's been completed.

Big turbochargers will usually experience a bottom end lag, and low capacity turbochargers spool up quickly but won't have the peak end power band gains.

Thankfully the range of turbochargers is always developing and we commonly find variable vane turbochargers, allowing the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbochargers divert the exhaust gases into two channels and flow these at differently designed vanes in the turbo. They also increase the scavenging effect of the engine.

It is not unusual that there is a limitation in the air flow sensor AFM/MAP on the Z24XE FlexPower 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 torque at a much lower level.

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

Uprating Z24XE FlexPower fuel injectors

You will need to ensure that the engine is not starved of fuel so must look at the fuelling when you start extending past 20% of a power increase.We strongly recommend you to be generous with your flow rate on the injectors.

As a rule of thumb add 20% capacity when fitting an injector, this allows for injector deterioration and allows some 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 Z24XE FlexPower performance exhausts

Only look to improve your exhaust if the existing exhaust is actually creating a restriction in flow.

On most factory exhausts you'll see your flow rate is still 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 from the engine but do not go 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.

Usual exhaust restrictions are in the emissions filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the Z24XE FlexPower

The Z24XE FlexPower engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the Z24XE FlexPower, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your Z24XE FlexPower engine please join us in our friendly forum where you can discuss tuning options in more detail with our Z24XE FlexPower owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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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.

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