Tuning the Mitsubishi 4G6

"Building the best modified Mitsubishi 4G6 engine!"

Carref prides itself on providing the latest tips and guides to your modification project.

In this article we review 4G6 tuning and highlight the ultimate upgrades. Mitsubishi 4G6 offer good returns when tuned and with the optimum motorsport parts like remapping, turbo kits and camshafts you will positively maximize your driving experience.

We rely on our visitors to pass on tips and tell us about their projects and what worked on their car, and this article is the culmination of the feedback we have received. First let us look at the history and specs of this engine and then consider which tuning modifications work best on it.

History of the Engine

4G61 displaces 1,595 cc (1.6 L)

• 1988–1992 Mitsubishi Mirage / Mitsubishi Colt (MPFI)
• 1988–1992 Dodge Colt / Plymouth Colt
• 1988–1992 Eagle Summit
• 1992–1995 Hyundai Elantra

4G62 1.8 L

• 1980–1987 Mitsubishi Lancer EX 1800GSR or 1800GT (A175A)
• 1981–1986 Mitsubishi Delica/L300/Express
• 1983–1987 Mitsubishi Chariot HR
• 1983–1989 Mitsubishi Cordia
• 1983–1989 Mitsubishi Tredia
• 1984–1988 Mitsubishi Galant/Eterna

4G63/G63B

See separate article for this engine

• 4G63 Tuning

4G64

• 1993-1997 Mitsubishi Chariot
• 1988–2006 Mitsubishi Delica/Van
• 1997-1999 Mitsubishi Eclipse
• 1997-1999 Mitsubishi Montero Sport (North American, ES model)
• 2000-2005 Mitsubishi Eclipse
• 1994–2003 Mitsubishi Galant
• 1990–present Mitsubishi L200
• 1996–1998 Mitsubishi Magna (codenamed 4G64-S4 TE-TF series)
• 1990–1996 Mitsubishi Mighty Max
• 1998-2005 Mitsubishi Montero (V11 - 2 door) Latin America
• 2001 Mitsubishi Airtrek
• 2003 Mitsubishi Outlander
• 1987–1990 Mitsubishi Sapporo
• 1986-2005 Mitsubishi Triton
• 2005 Mitsubishi Zinger
• 1998–2004 Mitsubishi Space Wagon

Tuning the Mitsubishi 4G6 and best 4G6 performance parts.

What are the most effective 4G6 modifications

The ultimate 4G6 parts on an engine are as we have found the ones that give the best value for money.

We won't be swayed by popular 4G6 parts, they need to be cost effective.

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.

Fast road cams commonly increase the bhp and torque throughout the rpm range, you could drop a little low down torque but your higher rpm power will be lifted.

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

A Competition camshaft won't do well if driving in heavy traffic.

You should ideally optimize your torque band to your typical driving style so for a road car stick with a shorter duration 4G6 camshaft

Some 4G6 engines respond better to less aggressive camshaft durations than others.

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

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.

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Modifying to Stage 1:

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

Modifying to Stage 2:

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

Modifying to Stage 3:

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

ECU flashing helps fully realize the full potential of all the parts you've done to your 4G6.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but your mileage may vary depending on the parts you've done and the condition of your engine.

It is vital to any engine modification job to push air and fuel into each cylinder

Intake headers carry the air from the filter and allow it to be drawn into the engine cylinders.

Structure and flow rate of the Plenum can make a big difference to to fuel mixing and power on the 4G6.

Many mass produced engine plenum chambers are needing an upgrade, although some makers provide decently flowing plenum chambers.

Adding a 4G6 larger valve kit, doing a bit of port work and head flowing will also boost power, and as an added benefit will permit raising the power increase on other modifications.

Which turbo upgrades are best?

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 4G6

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

When your motor is turbo charged parts are more reliable and turbo charged engines already contain better components.

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

Discover these limits and fit more solid crank and pistons to survive the power.

We've seen people spending a lots of money on turbocharger upgrades on the 4G6 only to see the motor literally blow up just after it's first rolling road session.

Larger capacity turbo units commonly suffer no power at low rpm, and small turbo units spool up quickly but don't have the top end torque gains.

Thanks to progress the market of turbo chargers is always evolving and we now see variable vane turbo chargers, permitting the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbo chargers divert the exhaust gases into a couple of channels and push these at differently angled vanes in the turbo charger. They also boost the scavenging effect of the engine.

It is not unusual that there's a limit in the air flow sensor (AFM/MAF/MAP) on the 4G6 when a lot 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 bhp and torque at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although more challenging to configure. We have this in depth look at twinchargers if you want to read more.

Fuelling

You will need to ensure that the engine is not starved of fuel so need to look at the fuelling when you start going beyond 20% of a torque increase.We would recommend you to over specify your injectors flow rate.

The rule of thumb is to add 20% to the flow rate when fitting an injector, this allows for injector deterioration and provides a little spare capacity should the engine need 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 NASP engines

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

4 Cylinder supercharged engines

• 58 PSI 312cc/min 200hp
• 58 PSI 468cc/min 300hp
• 58 PSI 625cc/min 400hp
• 58 PSI 937cc/min 600hp

Choosing the right performance exhaust

One of the most common mistakes and problems we see in tuning projects is usually down to the exhaust, or rather a poorly chosen exhaust for your engine.

You should look to improve your exhaust if the current exhaust is creating a restriction in flow.

On most factory exhausts you'll find your 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 air through the engine.

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

Typically exhaust restrictions can be located the emissions filters installed, so adding a higher flowing sports alternative will help avoid this restriction.

Weak spots Issues & problem areas on the 4G6

The 4G6 engines are generally reliable and solid as long as they are regularly serviced and maintained.

Regular oil changes are vital on the 4G6, especially when tuned and will help extend the life and reliability of the engine.

For more information on Tuning your 4G6 engine please join us in our friendly forum where you can discuss tuning options in more detail with our 4G6 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 parts work best for them on each model of car. Comments are used to improve the accuracy of these 4G6 articles which are continually updated.

This article was written by Waynne Smith on TorqueCars, and I appreciate your feedback and suggestions. This entry was filed under Mitsubishi. You can leave a response below or join TorqueCars forum to discuss this article and car modification in detail with our members.

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