Mitsubishi 4G63 Tuning

"All you need to know about tuning the Mitsubishi 4G63 engine!"

The 4G63 is one of our most talked about engines, and for good reason.

When Rallyart took it and tuned it we saw a phenomenally powerful 2.0 4 cylinder engine. They are solid and reliable and give good returns for pretty much every mod you throw at it.

We've seen tuners pushing over 1000hp from the 4G63 which, although prohibitively expensive it does give you inspiration and shows how capable these blocks are.

Our aim here is to detail the best approach to 4G63 tuning and highlight the premier modifications.

Mitsubishi 4G63 are good project engines and with the best sports upgrades like ECU maps, turbo improvements and camshafts you will substantially increase your driving enjoyment.

History, Power & Specs of the Engine

4G63 G63B 1,997 cc (2.0 L)

Here are some of the most notable versions:

  1. 4G63 (1980-1988) - This was the first version of the 4G63, which was produced from 1980 to 1988. It was a single overhead cam (SOHC) engine with a displacement of 2.0 liters and produced up to 135 horsepower. The intake ports were small and round, while the exhaust ports were larger and rectangular.
  2. 4G63T (1988-2007) - This was the turbocharged version of the 4G63 engine, which was produced from 1988 to 2007. It featured a dual overhead cam (DOHC) design and produced up to 300 horsepower in some applications. This version of the engine was used in various performance models such as the Mitsubishi Lancer Evolution and the Eclipse. The intake and exhaust ports were larger than those on the early 4G63, and the head featured an integrated exhaust manifold.
  3. 4G63T Evolution - The Lancer Evolution models of the 4G63T engine, which were produced from 1992 to 2007, featured a DOHC head with a 16-valve design, as well as a larger turbocharger and intercooler. The intake and exhaust ports were further optimized for high-performance use, and the engine was capable of producing up to 300 horsepower in some applications.
  4. 4G63T GDI (1996-2002) - This was a variation of the 4G63T engine that used gasoline direct injection (GDI) technology, which was produced from 1996 to 2002. It produced up to 250 horsepower and was used in the Mitsubishi Legnum and Galant VR-4. The head design was similar to that of the 4G63T, but with further improvements to the intake and exhaust ports.
  5. 4G63 MIVEC (1992-present) - This version of the engine featured Mitsubishi's variable valve timing and lift electronic control (MIVEC) system, which was first introduced in 1992. It is available in both SOHC and DOHC versions, and is still in production today.
  6. 4G63 RVR (1991-1997) - This was a variation of the 4G63 engine that was used in the Mitsubishi RVR (known as the Mitsubishi Space Runner in some markets). It featured a SOHC design and produced up to 170 horsepower.

Overall, there were several different heads and port sizes used on the 4G63 engine over the years, depending on the application and market. Swapping heads is often a good cheap upgrade option but I'd encourage you to do your research carefully.

The engine is very smooth running, primarily due to the twin balancing shafts Mitsubishi fitted to absorb vibrations.

Tuning the Mitsubishi 4G63 and best 4G63 performance parts.

Best 4G63 tuning mods

The greatest 4G63 mods on an engine are obviously the ones that give the best value for money.

We won't be swayed by popular 4G63 mods, they need to be cost effective. Limits on stock internals is around 400hp for most turbo variants of the 4G63 and we often see 500hp tuned versions but would strongly recommend a stronger rods and pistons around this point.

The crank, if the stronger forged version has been able to handle around 700hp.

Early engine parts were not as strong, so replacing with the later forged components can provide a cost effective upgrade, and these can be Cryo treated to further improve their resilience and wear resistance.

Significant gains on the 4G63 can be made from cam upgrades but Mivec already alters cam timing so other than more lift the advantages and cost of fast road cams are questionable on these versions.

Altering the cam profile alters the intake and exhaust durations and the amount of valve lift in the engine and can dramatically change the engines power and power output typically pushing it higher up the RPM range.

Fast road cams normally boost the performance through the rev range, you may lose a little low end bhp but the higher rpm power will be better.

The Hydraulic valve lifters and roller rockers work really well and minimize the need for constant adjustment and reduced engine noise.

Motorsport cams, boost 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 won't do well if on the daily commute, because the lumpy idle will make the car prone to stall and smooth driving at low rpm becomes impossible. If you are developing a track car this doesn't matter as you are in the high end of your RPM range anyway and that is where you want the power to be.

You should ideally optimize your engines power to your usage of the car so for a car driven daily stick with a mild fast road 4G63 camshaft

Each engine responds better to different camshaft durations so set your engine up on a rolling road.

The engine timing and fuelling also will make differences on the torque gains you'll make.

Altering 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.

Please watch our 4G63 Mods video which covers the basic principles of tuning your 4G63. Be sure to keep up with our latest YouTube content and subscribe.

Best Engine Mods for your 4G63

  1. Engine Tunes - engine tuning/remapping provides the most advantage in terms of cost savings,  aftermarket ECUs, and piggyback ECUs are all alternatives Autronics is a brand that crops up regularly and is highly regarded.
  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 - 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 on your 4G63.
  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.

4G63 Tuning Stages

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

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

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

Review your options and then find your parts and set yourself a power target to avoid wasting your time and money.

Remapping the 4G63 ECU

remap helps fully realize the full potential of all the tuning parts you've fitted to your 4G63.

Because the factory ECU is locked flashing is not an option on most if not all EVO's (please let us know in the comments if you know anyone offering remaps), 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. An alternative would be a boost controller and raising the fuel rail pressure which can work out cheaper but is usually less impressive.

The aftermarket ECU such as Autronics or AEM, will take over all apects of engine management, controlling fuel and turbo boost and ignition timing.

Because they generally operate at higher OPS (operations per second) than factory equipment they are generally more flexible and allow finer control over the tune.

It will usually give you around 30% more power on turbocharged vehicles and you can expect to see around 15% on NA (naturally aspirated) engines, but your results may depend much on the tuning parts you've carried out and the condition of your engine.

It is the aim to any car tuning job to pull more air and fuel into your 4G63

Intake manifolds take the air from the filter and allow it to be drawn into the engine and mixed with fuel.

The shape and flow rate of the Intake manifolds can make a substantial improvement to fuel delivery on the 4G63.

Commonly we find the intake are in desperate need of aftermarket parts, although a few car makers provide reasonably good intake.

Increasing the 4G63 valve size, doing a bit of 3 or 5 angle valve jobs and porting and head flowing will also increase performance, and significantly will give you increasing the performance increase on other tuning mods.

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 4G63

Discover the differences between the 4G53 Engines in our video overview.

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 tuning parts are giving better power gains and turbocharged engines use better components.

However most engines will need better parts at higher power limits

See where you'll find these restrictions and upgrade to more solid crank and pistons to utilize the power.

There are many drivers spending a lot of money on turbo charger upgrades on the 4G63 only to suffer the humiliation of seeing the 4G63 explode just after it's been completed.

Larger turbo chargers tend to suffer low end lag, and little turbo chargers spool up really quickly but won't have the top end power band gains.

In the last 10 years the selection of turbo chargers is always moving on and we now see variable vane turbo chargers, where the vane angle is altered according to speed to lower lag and increase top end power.

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

It is common that there is a limitation in the air flow sensor MAF/MAP on the 4G63 when a lot more air is being sucked 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 bhp at a much lower level.

Boost controllers

A turbo boost controller is an aftermarket device that is often used to adjust the boost pressure on turbocharged engines such as this the 4G63.

Because the 4G63 engine uses a turbocharger to increase the amount of air that enters the engine, which in turn allows more fuel to be burned and produces more power alterations to the boost make a substantial power difference.

The amount of boost pressure generated by the turbocharger is controlled by a wastegate, which is designed to open at a certain pressure level to limit the amount of boost.

Factory systems tend to be slower and more binary in their operation compared to the subtleties of an aftermarket boost controller.

A turbo boost controller works by adjusting the signal to the wastegate actuator, which allows the boost pressure to be raised or lowered beyond the factory setting. This can result in increased power and torque from the engine, as well as better throttle response and more consistent performance.

The more intelligent the boost controller the finer control you have with it anticipating your power needs and ensuring the turbo responds well.

On the 4G63 engine, a turbo boost controller can be particularly useful for those looking to tune the engine for higher levels of performance, such as in racing or other high-performance applications.

By adjusting the boost pressure, it is possible to achieve higher levels of power and torque, although this should be done carefully and with appropriate supporting modifications to ensure the engine remains reliable and does not suffer from premature wear or damage.

For older engines like the 4G63, a boost controller can be a useful tool for those looking to tune the engine for performance and in some cases is comparable to a tune/remap or aftermarket ECU in terms of performance gains.


You will need to ensure that the engine is not starved of fuel so should ramp up the fuelling when you start exceeding 20% of a bhp and torque increase.Most tuners we speak with say to be generous with your injectors flow rate.

As a rule of thumb add 20% when fitting an injector, which takes into account injector deterioration and allows you some 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 58psi of fuel pressure at idle.

4 Cylinder turbocharged engines

  • 58 PSI 340cc/min 200hp
  • 58 PSI 511cc/min 300hp
  • 58 PSI 682cc/min 400hp
  • 58 PSI 1022cc/min 600hp

4 Cylinder NA (naturally aspirated) engines

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

Ways to Increase The Fuel Flow & Delivery

One of the main goals of upgrading the fuel system is to increase the amount of fuel that can be delivered to the engine. There are a few components to focus on to achieve this aim.

This can primarily be achieved by upgrading the fuel injectors to larger, high-flow injectors that can supply more fuel, or by increasing the fuel pressure to the injectors using an adjustable fuel pressure regulator.

There will be limits though at certain points which need to be overcome, and it makes sense to address these before you start getting problems.

Install a fuel pump

A high-performance fuel pump can be installed to supply more fuel to the injectors, particularly at higher levels of boost and power output.

A high-quality fuel pump with a larger flow rate and suitable pressure rating is recommended.

Upgrade fuel lines and fittings

Upgrading the fuel lines and fittings to larger diameter, high-flow components can help to ensure that the increased fuel flow rate can be maintained throughout the system.

This can also help to prevent fuel starvation or pressure drop at higher levels of demand.

Install a fuel surge tank

For high-performance applications, a fuel surge tank can be installed to prevent fuel starvation during high-G cornering or acceleration.

This type of tank ensures that a constant supply of fuel is available to the engine, even when fuel sloshes around in the tank.


You should look to increase your exhaust if your exhaust is actually creating a flow problem.

On most factory exhausts you should find that the flow rate is good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Note that with the widest exhaust you can buy you'll slow the exhaust rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions are in the filters installed, so adding a freer flowing performance catalyst removes the restriction. We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars.

Weak spots Issues & problem areas on the 4G63

The 4G63 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.

Crank Walk

This is where thrust bearings start to wear causing the crank to wonder causing lots of problems and vibrations which generally deteriorate at an accelerated pace. This affects about 1 in 8 engines, particularly those with the 7 bolts on the crank/flywheel.

This causes the crankshaft to move excessively from side to side in the engine block - not great.

Crank walk is typically caused by excessive bearing clearances, which can be caused by a number of factors including inadequate lubrication, improper assembly, and high mileage. The excessive movement of the crankshaft can cause damage to the engine bearings, leading to increased engine wear and potentially catastrophic engine failure.

The 7 bolt crank/flywheel versions have weaker journals.

Con Rod & Crankshaft breaking

There were some issues with the forging on early versions of the 4G63 engine, particularly in the first generation of the engine that was produced from 1980 to 1988. The original connecting rods and crankshafts in these engines were made from cast iron, which was not as strong as the forged steel used in later versions of the engine.

This could result in bending or breaking of the connecting rods and crankshafts, especially under high-performance applications or with modifications. Additionally, some early versions of the engine may have had issues with the casting quality of certain components, which could result in failures or premature wear.

To address these issues, Mitsubishi eventually switched to using forged steel components in later versions of the engine, which increased their strength and durability. Aftermarket components are also available to upgrade the strength of the engine, particularly for those using the engine in high-performance applications.

Overall, while early versions of the 4G63 engine had some forging issues, they have largely been addressed in later versions of the engine and with aftermarket components. With proper maintenance and upgrades, the 4G63 engine can be a reliable and capable powerplant for a variety of applications.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

Regular oil changes are vital on the 4G63, especially when tuned and will help extend the life and reliability of the engine. The balance shafts and crank bearings will last much longer if you use a good quality oil and keep on top of the servicing intervals, shortening them if you've added more power.

If you would like to know more, or just get some friendly advice on Tuning your 4G63 engine please join us in our friendly forum where you can discuss tuning options in more detail with our 4G63 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which upgrades work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date, and help improve the accuracy of these 4G63 tuning guides which get regular updates and revisions.

Please Check out my YouTube channel, we're regularly adding new content...

PLEASE HELP: I NEED YOUR DONATIONS TO COVER THE COSTS OF RUNNING THIS SITE AND KEEP IT RUNNING. I do not charge you to access this website and it saves most TorqueCars readers $100's each year - but we are NON PROFIT and not even covering our costs. To keep us running PLEASE Donate here

If you liked this page please share it with your friends, drop a link to it in your favourite forum or use the bookmarking options to save it to your social media profile.

Feedback - What do You Think?

Please use our forums if you wish to ask a tuning question, and please note we do not sell parts or services, we are just an online magazine.

Help us improve, leave a suggestion or tip

Your Constructive comments on this article, I really want to improve this article with your help and suggestions.

Please watch this video and subscribe to my YouTube channel.

One Response to “4G63 Tuning”

  1. Don Creek says:


    Thanks for the article. I drive a 1994 Mitsubishi Delica van 4×4 2000cc. Its heavy and i live at 12000′ above sea level, going up to 5000 meters and down to almost sea level. But mostly at 10000 to 13000 feet. Want can somebody (not me) do to help this undepowered carburated beast out? Air filter? Ok. Maybe the cat? Im in Bolivia.

    Certainly dont expect perfection.


Member Benefits

Join our forum today and benefit from over 300,000 posts on tuning styling and friendly car banter.

You will also have full access to the modifed car gallery, project car updates and exclusive member only areas.

(All car owners of all ages and from all countries are welcome).

BMW 335i - 2021 COTY

We gave the BMW 335i our coveted car of the year award, read more about this awesome car and see why 335i Tuning Guide

Tips for N54 Tuning

Tips for N55 Tuning
Tips for B58 Tuning

Popular articles

Diesel tuning
ECU remapping
double de clutch
Induction Kits
Customize a car
Chip tuning
Modified car insurance
Track day insurance
Diesel Remaps
MPG calc
DPF cleaning
Stage 1 Tuning

Silicone Pipe

Silicone hoses

Performance Clutches

Clutch tuning: performance clutch modifications and triple plate clutches setup

Re Upholstery Cars

Re-upholstery for your car from seats to dashboard.

Split Bonnets

Creating a custom self opening split bonnet or split hood.

Stage 2 Mods

Stage 2 Mod Guide

Diesel Hot Hatch

Diesels? On Torquecars, Really?

MPG Calculator

MPG calculator UK miles per Gallon – calculate MPG