Tuning the Hyundai/Mitubishi Omega / 8A8 / G8AA

"Comprehensive guide to performance tuning the Hyundai Omega engine!"

This pages aim is to examine the world of the options for your Omega 8A8 / G8AA tuning and show the greatest modifications. Hyundai Omega are popular engines and with the right performance parts like remapping, turbo improvements and camshafts you will substantially increase your driving enjoyment.

Just because particular mods are appear in lots of Omega projects it doesn't mean its worth having, instead we will recommend only what we regard as the greatest mods that will give your Omega 8A8 / G8AA the best value for money to power increase.

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

NB: Fast road camshafts tend to push up the power throughout the rpm range, you could drop a little bottom end bhp but the high end rpm power will be better.

Motorsport and race camshafts, push up the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

In a daily driver should ideally to optimize your engines power to your cars usage.

I'd be surprised if you have found a Omega 8A8 / G8AA Race camshaft is a pleasure to live with when on the daily commute.

Some Omega engines respond better to more or less aggressive cam durations so view each engine as unique.

The map and fuel pump and injectors also have an effect on the power gains you'll get.

A longer valve duration 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.

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

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

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

The Omega 8A8 / G8AA engines make great tuning projects and thankfully there is a growing number of parts and tuning parts around.

Mapping will help to establish the full potential of all the upgrades you've fitted to your Omega 8A8 / G8AA.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output often depend much on the upgrades you've applied and the condition of your engine.

Feeding more fuel and air into your Omega is the whole point to any performance tuning task.

Intake manifold transmit the air during the suck phase from the air filter and allow it to be fed into the engine cylinders with fuel for the squish phase.

The shape and flow characteristics of the Intake headers can make a noticeable change to fuel engine efficiency on the Omega 8A8 / G8AA.

It's not uncommon that plenum chambers are needing aftermarket parts, although a few car makers provide decently flowing plenum chambers.

Fitting big valve kits, carrying out 3 or 5 angle valve jobs and porting and head flowing will also lift power, and significantly will give you a better power increase on other parts.

Turbo upgrades

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 Omega 8A8 / G8AA

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.

If your motor is fitted with a turbocharger parts are going to net you a larger power gain and you'll see that turbo engines already contain more solid components.

However engines have weakspots

We recommend you find these limits and fit better quality components to cope with the power.

We see many people spending a a stack of money on turbo upgrades on the Omega 8A8 / G8AA only to see the whole thing go up in smoke soon after it's been finished.

Bigger capacity turbo units often suffer a bottom end lag, and little turbo units spool up quickly but don't have the high rpm engines power gains.

We are pleased that the selection of turbo chargers is always evolving and we now see variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end bhp and torque.

Twin scroll turbo chargers divert the exhaust gases into two channels and direct these at differently angled vanes in the turbocharger. They also boost the scavenging effect of the engine.

It is common that there is a restriction in the air flow sensor MAF/MAP on the Omega 8A8 / G8AA when considerably more air is being drawn into the engine.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting performance at a much lower level.

Adding a supercharger or additional turbo will make large power gains, although harder to setup. We have this article on twincharging if you want to read more.

Fuelling upgrades and mods

Don't overlook the need to raise the fuel system when you are increasing the torque - it makes the car more thirsty. Most tuners we speak with say to be generous with your injectors flow rate.

The rule of thumb is to add 20% capacity when specifying an injector, this takes into account injector deterioration and provides a bit of spare capacity should the engine require 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.

Exhaust upgrades and mods

You should look to improve your exhaust if the existing exhaust is actually causing a restriction.

On most factory exhausts you'll find the exhaust flow rate is still good 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 can help equal out the flow of gases through the engine.

But if your exhaust is too large, ie: over 2.5 inches bore, you will lose a lot of your flow rate and end up losing power and torque.

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

Weak spots, Issues & common problem areas on the Omega 8A8 / G8AA

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

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

For more information on Tuning your Omega engine please join us in our friendly forum where you can discuss tuning options in more detail with our Omega 8A8 / G8AA owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

History of the Engine

The Hyundai Omega engine or G8AA (aka the 4.5D or Mitsubishi 8A8)

The engine block was cast by Hyundai and the head was produced by Mitsubishi. We love to see collaboration between car makers and have seen some impressive engines born from these partnerships.

  • 4498cc has a 10.7:1 compression ratio
  • DOHC with multiport fuel injection
  • Power output is 256 hp 260 PS @5,500 rpm  275 lbft @2,500 rpm

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

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

We really like hearing from our readers, and hearing about which parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our guides and tips are kept up to date.

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