Modding upgrading and tuning the Mitsubishi 6A12 engine!

Modifying and improving: "6A12 Modifications"

6A12 Modifications Guide

How to modify and upgrade the Mitsubishi 6A12

"Comprehensive guide to tuning the Mitsubishi 6A12 engine!"

Forums like the one at TorqueCars often are getting messages requesting information on how to improve the 6A12 from people wanting to know what are the best tips for 6A12 upgrades. So let us look into Mitsubishi 6A12 mods and outline the best upgrades on this great engine and point out some problems along the way.

The Mitsubishi 6A12 make a good tuning project and with a few sensible sports upgrades like remaps, turbo upgrades and camshafts you will positively improve your driving pleasure.

We shall review 6A12 tuning and report on the best modifications for your car.

Just because particular tuning parts are appear in lots of 6A12 projects it doesn't mean it is good, so we'll focus on the optimum tuning parts that will give your 6A12 the best power gain for you money.

Without us subscribing to the popular mentality of 'if it's shiny and makes more noise it must be good' you seem to get in many tuning magazines and on car forums'.

6A12 induction kits

Improving air intake on the 6A12

You need air matched to fuel for an engine to work. If there is little supply of fuel then it will run lean, if there is little flow of air it runs rich resulting in lost power and potentially damaging the engine. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So Pulling more fuel and air into your 6A12 is vital to any tuning project.

It is not unusual that there is a limit in the air flow sensor AFM/MAF on the 6A12 when loads more air is being fed into the engine.

When tuning you may well find you need to get an air sensor or flow meter capable of upto 4 bars to cope with quite large power gains, whereas the OEM air sensor limited bhp at a much lower level.

Headers transmit the on the suck phase from the air cleaner and allow it to be sucked into the engine and mixed with fuel.

The size of bore and shape and rate of flow of the Plenum can make a large improvement to fuel engine efficiency on the 6A12.

I usually find headers are improved through performance upgrades, although a few OEM provide reasonably good headers.

Adding a 6A12 larger valve kit, carrying out 3 or 5 angle valve jobs and porting and head flowing will also improve torque, & importantly will allow you to get increasing the torque increase on other upgrades.

6A12 performance cam tips.

Different 6A12 engines respond better to less aggressive camshaft durations so set your engine up on a rolling road.

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

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.

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 power band gains are on offer for cam upgrades.

NB: Fast road camshafts usually increase the bhp through the rev range, you could drop a little low down power but the high end rpm power will be higher.

Competition 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.

For a typical daily driver you need to optimize your torque band to your cars usage.

You will never have ever thought a 6A12 Competition camshaft is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the 6A12

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 6A12 parts:

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

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

Stage 2 6A12 parts:

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

Stage 3 6A12 parts:

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

Plan your options and then find your parts and set yourself a power target to save yourself from expensive mistakes.

ECU mapping will help fully realize the full potential of all the modifications you've done to your 6A12.

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 your mileage usually rely on the modifications you've applied and the condition of your engine.

Turbo modifications on the 6A12

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 6A12.

The more air you can 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 has a turbocharger mods are more reliable and most turbo engines are made using stronger components.

However most engines have weakspots

Research these limitations and fit stronger pistons, crank and engine components to cope with the power.

There are many car owners spending a loads of money on turbo charger upgrades on the 6A12 only to have the engine explode soon after it's been enthusiastically driven.

Bigger capacity turbochargers often suffer low end lag, and smaller turbochargers spool up quickly but don't have the peak end power band gains.

Thankfully the choice of turbo chargers is always evolving and we are seeing variable vane turbo chargers, allowing the vane angle is altered according to speed to lower lag and increase top end performance.

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

Beefing up the air intake by adding a supercharger or additional turbo will help you achieve very large bhp and torque gains, although harder to get working. We have this guide to twinchargers if you want to read more.

Tips about fuel supply on the 6A12

You will need to ensure that the engine is not starved of fuel so will have to look at the fuelling when you start going beyond 20% of a bhp and torque hike. Care modifiers usually say to over specify your injectors flow rate.

The rule of thumb is to add 20% capacity when specifying an injector, which takes into account injector deterioration and provides you some 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 6A12 performance exhaust upgrades

The only time you should look to increase your exhaust system with an upgraded one is if the current exhaust is actually causing a restriction.

On most factory exhausts you'll see the flow rate is good 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 increase the flow of air through the engine.

But if your exhaust is too large, ie: it's over two and a half inches diameter, you will lose a great deal of the exhaust flow rate and end up lacking power and torque.

Typically exhaust restrictions can be traced to the catalyst installed, so adding a faster flowing high performance alternative will help avoid this restriction.

Decats (NB:catalysts reduce harmful engine emissions) is illegal in most countries and regions.

Faults issues and things to look out for on the 6A12

Like most engines an 6A12, 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 6A12, failure to do this will exacerbate engine wear, on a tuned 6A12 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 6A12 why not pop over to the forums at TorqueCars where you can chat about 6A12 tuning options and read about others projects who may be planning to do similar modifications on their 6A12.

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