Modding tuning and best performance upgrades on the Vauxhall X14YFH engine!

Tuning guide "X14YFH Modifications"

X14YFH Modifications Guide

How to modify and upgrade the Vauxhall X14YFH

"Comprehensive guide to tuning the Vauxhall X14YFH engine!"

Sites like TorqueCars are regularly getting messages requesting info on how to improve the X14YFH from people inquiring about getting more power from the X14YFH and wanting to know what are the things tuners are recommending when it comes to X14YFH power upgrades. So let us look into Vauxhall X14YFH parts and outline the best upgrades on this great engine and point out some frequent tuning mistakes along the way.

In this article we detail the best approach to X14YFH tuning and highlight the greatest modifications. Vauxhall X14YFH are popular engines and with the right motorsport parts like remapping, turbo kits and camshafts you will greatly increase your driving opportunities.

Just because particular parts are appear in lots of X14YFH projects it doesn't mean you should fit it, so we'll focus on the optimum parts that will give your X14YFH the best power gain for you spend.

Without us subscribing to the common myth of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

X14YFH induction kits

Improving air intake on the X14YFH

You need air matched to fuel for an engine to work. If there is not enough fuel then it will run lean, if there is insufficient air it runs rich losing power . We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the aim to any tuning job to feed air into the X14YFH engine but this has a knock on effect with the air flow sensor.

It is not unusual that there's a limit in the air flow sensor (AFM/MAF/MAP) on the X14YFH when considerably more air is being drawn into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited torque at a much lower level.

Engine intake manifolds flow the air during the suck phase from the air cleaner and allow it to be sucked into the engine cylinders.

Design and flow characteristics of the Plenum can make a noticeable change to fuel mixing and power on the X14YFH.

On popular production engines plenum chambers are improved through motorsport parts, although some makers provide reasonably good plenum chambers.

Adding a X14YFH larger valve kit, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also improve performance, this will raise potential for a greater performance increase on other parts.

X14YFH performance cam tips.

Each engine responds better to less aggressive cam durations so set your engine up on a rolling road.

The map and injectors and fuel pump also will say much on the torque gains you'll achieve.

A longer valve duration 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.

The cam profile plays a big part in the engines power output so cam upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen cam profile, so large engines power gains are on offer for cam upgrades.

NB: Fast road cams commonly raise the power across the rev range, you could drop a little bottom end power but higher rpm power will be better.

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

A Race camshaft is not great driving in heavy traffic.

You should ideally match your engines power to your cars usage so for a car driven daily stick with a shorter duration X14YFH camshaft

Stage 1, 2 and 3 mods for the X14YFH

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 X14YFH parts:

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

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

Stage 2 X14YFH parts:

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

Stage 3 X14YFH parts:

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

The X14YFH units respond well to mods and thanks to their popularity there are plenty of mods and tuning parts around.

Remaps allows a tuner to unlock the full potential of all the mods you've done to your X14YFH.

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 your mileage usually vary depending on the mods you've carried out and the condition of your engine.

Turbo modifications on the X14YFH

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 X14YFH.

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 a car is turbocharged, parts are giving better power gains and turbocharged engines are built using stronger components.

However most engines have limits

See where you'll find these restrictions and fit higher quality components to handle the power.

We've seen people spending a loads of money on turbo upgrades on the X14YFH only to suffer the indignity of watching the motor catastrophically fail soon after it's used in anger.

Larger capacity turbo chargers commonly experience no power at low rpm, and smaller turbo chargers spool up quickly but do not have the peak rpm engines power gains.

Thanks to progress the selection of turbo chargers is always improving and we commonly find variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo chargers divert the exhaust flow into a couple of channels and flow these at differently angled vanes in the turbo charger. 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 performance gains, although more challenging to configure. We have this article on twincharging if you want to read more.

Tips about fuel supply on the X14YFH

Don't miss you'll need to look at the fuelling when you are increasing the power - it makes the car more thirsty. Experienced mechanics will tell you to over specify your injectors flow rate.

The accepted safe increase is to add another 15% when buying an injector, this takes into account injector deterioration and provides a bit of 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 X14YFH performance exhaust upgrades

You only need to to replace your exhaust system with an upgraded one is if your current exhaust is creating a restriction in flow.

On most factory exhausts you should find that your flow rate is still 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 could will reduce the flow rate. Stick to one and a half to two and half inches as a rule of thumb.

The usual suspects causing problems in your exhaust flow rate are in the catalyst installed, so adding a better flowing race alternative will help avoid this restriction.

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

Faults issues and things to look out for on the X14YFH

Like most engines an X14YFH, 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 X14YFH, failure to do this will exacerbate engine wear, on a tuned X14YFH 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 X14YFH why not pop over to the forums at TorqueCars where you can chat about X14YFH tuning options and read about others projects who may be planning to do similar modifications on their X14YFH.

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