Modding and performance tuning parts for the Subaru EJ22 engine!

Modifying and improving: "EJ22 Modifications"

How to modify and upgrade the Subaru EJ22

"Comprehensive guide to tuning the Subaru EJ22 engine!"

Sites like TorqueCars are always getting posts asking about how to improve the EJ22 from people inquiring about getting more power from the EJ22 and wanting to know what are the optimum EJ22 upgrades. So let us look into Subaru EJ22 tuning mods and outline the best modifications on this great engine and point out some common pitfalls along the way.

We shall detail the best approach to EJ22 tuning and show the premier modifications. Subaru EJ22 really good project engines and with the ultimate performance tuning mods like remapping, turbo upgrades and camshafts you will definitely enhance your driving opportunities.

The best EJ22 modifications on an engine are typically the ones that give the biggest return for your money.

We won't be swayed by popular EJ22 modifications, they need to be cost effective.

EJ22 induction kits

Improving air intake on the EJ22

You need fuel and air for an engine to work. If there is not enough fuel then it will run lean, if there is not enough air it runs rich losing power which risks damage to the EJ22. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Forcing more fuel and air into your EJ22 is the aim to any engine tuning job.

You'll commonly see there's a limitation in the air flow sensor (AFM/MAF/MAP) on the EJ22 when loads 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 performance at a much lower level.

Intake manifolds take the air during the suck phase from the filter and allow it to be pulled into the engine cylinders with fuel for the squish phase.

Design and flow characteristics of the Air Intake manifolds can make a large change to fuel mixing and power on the EJ22.

Many mass produced engine intake are crying out for aftermarket tuning parts, although some makers provide well optimised intake.

Big valve conversions on the EJ22, carrying out EJ22 port enlargement and head flowing will also improve bhp and torque, and importantly will raise potential for an improved bhp and torque increase on other modifications.

EJ22 performance cam tips.

Different EJ22 engines respond better to different cam durations so view each engine as unique.

The ECU mapping and fuel pump and injectors also have a large bearing on the power gains you'll make.

Longer valve 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.

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 bhp gains are on offer for cam upgrades.

NB: Fast road camshafts tend to increase the bhp across the rpm band, you could drop a little bottom end bhp but top end will improve.

Competition 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 camshaft is not great in heavy traffic.

You should ideally optimize your engines power to your typical driving style so for a car used daily stick with a shorter duration EJ22 camshaft

Stage 1, 2 and 3 mods for the EJ22

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 EJ22 parts:

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

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

Stage 2 EJ22 parts:

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

Stage 3 EJ22 parts:

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

The EJ22 units make great tuning projects and we note that there is a growing number of parts and performance parts out there.

ECU mapping should help to fully realize the full potential of all the parts you've done to your EJ22.

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 parts you've fitted and the condition of your engine.

Turbo modifications on the EJ22

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 EJ22.

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.

If the engine has a turbocharger upgrades are more reliable and most turbo engines are built using harder and stronger components.

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

See where you'll find these restrictions and install better quality components to utilize the power.

There are many people spending a a stack of money on turbo charger upgrades on the EJ22 only to have the car explode on it's first outing after it's completed.

Larger capacity turbochargers will usually suffer low end lag, and low capacity turbochargers spool up quickly but won't have the peak end power band gains.

In the last 10 years the market of turbos is always improving and we now see variable vane turbos, where the vane profile is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbos divert the exhaust gases into a couple of channels and direct these at differently profiled vanes in the turbocharger. They also improve 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 get working. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the EJ22

When you lift the bhp you will need to look at to the fuelling.

More bhp needs more fuel. Care modifiers usually say to over specify your injector capacity.

The rule of thumb is to add 15% when fitting an injector, this takes into account injector deterioration and allows 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 EJ22 performance exhaust upgrades

The only time you should look to replace your exhaust system with an upgraded one is if your current exhaust is actually causing a flow problem.

On most factory exhausts you'll find 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 generally help improve air flow out of 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 traced to the catalyst and filters installed, so adding a better flowing 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 EJ22

Like most engines an EJ22, 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 EJ22, failure to do this will exacerbate engine wear, on a tuned EJ22 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 EJ22 why not pop over to the forums at TorqueCars where you can chat about EJ22 tuning options and read about others projects who may be planning to do similar modifications on their EJ22.

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