Hyundai Beta Tuning

"All you need to know about tuning the Hyundai Beta engine!"

We review Beta tuning and show the greatest modifications. It was available in the following engine codes G4GC, G4GF, G4GR, G4GB  and G4GM and appeared in quite a few cars, notably the Coupe and Elantra, and later the Kia Ceed, Cerato and Soul to name just a few.

It's size and power output was well suited to quite a few chassis styles and the engine received various tweaks over the years to improve it and refine it.

Hyundai Beta are popular cars and with the best performance tuning mods like a remap, turbo upgrades and camshafts you will really maximise your driving experience.

History, Power & Specs of the Engine

A straight 4 block with a DOHC configuration.

  • Beta 1.8D G4GM 1995 to 2003
  • Beta 2.0D G4GF 1996 to 2001
  • Beta 1.8D G4GB 2000-2010
  • Beta 2.0D G4GC 2001 2012

Best Beta parts

When talking about the best best for your Beta engine, we are going to tuning parts that give the best power gain for you money.

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

Fast road camshafts tend to increase the bhp and torque throughout the rev band, you may sacrifice a little low down torque but high end rpm power will be higher.

Race camshafts, increase 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 car used daily, really you should, ideally aim to optimize your torque band to your preferences.

I'd be shocked if you find a Motorsport and race camshaft is a pleasure to live with when in heavy traffic because low end power will be very lumpy. Competition cams are designed for maximum power at the top end of the RPM range, a place that most daily commutes will not permit!

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

The ECU mapping and fuel pump and injectors also will make differences on the bhp gains you'll achieve.

Longer valve durations can alter the bhp 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.

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Best Engine Mods for your car

  1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives.
  2. Fast road cams are one of the most significant mechanical changes, but they must be installed by someone who knows what they're doing and they are not always easy to source but you might find a local firm to regrind a stock camshaft.
  3. Intake and Exhaust - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by removing the restriction.
  4. Upgrades to turbochargers and superchargers - forced induction is the most efficient approach to increase air supply, allowing you to burn more fuel and make more power. It is one of the most costly upgrades but provides the best gains.
  5. Head work - The goals of porting and flowing the head are to get air flowing into the engine while removing flow restrictions and turbulence.

Typical stage 1 mods often include: Fast road camshaft, Sports exhaust header/manifold, Remaps/piggy back ECU, Panel air filters, Intake manifolds, drilled & smoothed airbox, AFM/MAP upgrades.

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

Typical stage 3 mods often include: Adding forced induction (turbo/supercharger), Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Crank and Piston upgrades to alter compression, Competition cam.

The Beta engines are fantastic to work on and we see that there are increasing numbers of parts and performance parts around.

Mapping will help release the full potential of all the tuning parts you've fitted to your Beta.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 15% more power on NA (naturally aspirated) engines, but your mileage will vary depending on the tuning parts you've done and the condition of your engine.

Shoving more air and fuel into the Beta engine is the main goal to any engine tuning job.

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

The bore size, shape and flow characteristics of the Intake manifolds can make a noticeable change to fuel mixing and power on the Beta.

Most air intake manifolds are needing motorsport parts, although some car makers provide reasonably good air intake manifolds.

Big valve conversions on the Beta, doing some port matching and head flowing will also improve performance, and as an added benefit will make space for increasing the performance increase on other upgrades.

Turbo upgrades

NA (naturally aspirated) 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 Beta

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

When the engine is fitted with a turbo tuning mods are going to make more power and you will discover turbo charged engines are built with more solid components.

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

It is important to find these restrictions and upgrade to higher quality components to utilize the power.

We see many drivers spending a loads of money on turbocharger upgrades on the Beta only to suffer the humiliation of seeing the whole thing catastrophically fail when it's been finished.

It is not unusual that there is a limit in the air flow sensor AFM/MAF on these engines when loads more air is being drawn into the engine.

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

Adding a supercharger or additional turbo will make large performance gains, although more challenging to install. We have a twincharger performance adding guide if you want to read more.


Don't omit to boost the fuelling when you are increasing the performance - it makes the car more thirsty. It is important to over specify your flow rate on the injectors.

The rule of thumb is to add 20% capacity when fitting an injector, this takes into account injector deterioration and gives 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.

All the following flywheel power targets will assume an injector duty cycle of 80% and a base of 58 psi of fuel pressure at idle.

4 Cylinder NA (naturally aspirated) engines

  • 58 PSI 285cc/min 200hp
  • 58 PSI 426cc/min 300hp


You may need to boost your exhaust if your exhaust is creating a flow problem.

On most factory exhausts you'll see the flow rate is ok 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 usually air flow from the engine but avoid an exhaust that is too big or you could very well end up with a reduced flow rate. So generally speaking, keep to 1.5 to 2.5 inches for best results.

Common exhaust restrictions are traced to the catalyst installed, so adding a better flowing high performance aftermarket one will improve air flow, and rather than doing an illegal decat, will keep the car road legal.

Weak spots Issues & problem areas on the Beta

The Beta engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Please let us know if there are any other problems or issues we have missed., we've seen these with over 200,000 miles, and still pulling well with no smoke or issues.

The Beta engine can be quite loud and has lots of vibration, this is quite normal and not a cause for concern but revised engine mounts can reduce this a little. If you get additional vibrations or rattles when braking or accelerating it could be an issue with the HT leads, soils or plugs, and replacing these will usually improve matters.

Regular oil changes are vital on the Beta, especially when tuned and will help extend the life and reliability of the engine.

Revs can stay quite high, this seems to be an ECU related issue and a reset usually clears this problem.

If you would like to know more, or just get some friendly advice 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.

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One Response to “Beta Tuning”

  1. ERIC SOTO says:


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