Modding tuning and best performance upgrades on the Mercedes M279 engine!

Tuners tips on "M279 Modifications"

M279 Modifications Guide

How to modify and upgrade the Mercedes M279

"Comprehensive guide to tuning the Mercedes M279 engine!"

Popular tuning sites like TorqueCars are regularly getting emails about how to improve the M279 from people inquiring about getting more power from the M279 and wanting to know what are the best tips for M279 upgrades. So let us look into Mercedes M279 tuning mods and outline the best modifications on this great engine and point out some potential pitfalls along the way.

Here we detail the best approach to M279 tuning and show the best modifications. Mercedes M279 great bases for a tuning project and with the best modifications like remapping, turbo kits and camshafts you will definitely maximize your driving fun.

When talking about the best parts for your M279 engine, we are going to focus on the mods that give the best value for money.

M279 induction kits

Improving air intake on the M279

You need air matched to fuel for an engine to work. If there is too little fuel then it will run lean, if there is insufficient air it runs rich sapping power which risks damage to the M279. We'll pick up on fuelling later in this article but for now we shall look at air supply.

So the goal to any car tuning job to get air into your M279 but this has a knock on effect with the air flow sensor.

It is common that there is a limitation in the air flow sensor AFM/MAP on the M279 when a lot more air is being pulled 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 performance at a much lower level.

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

Shape and rate of flow of the Intake can make a substantial change to fuel delivery on the M279.

We often see intake manifold are in dire need of an upgrade, although some car makers provide reasonably well designed intake manifold.

Fitting big valve kits, doing a bit of port matching and head flowing will also increase performance, the fantastic side effect is it will raise potential for a better performance increase on other tuning mods.

M279 performance cam tips.

Each engine responds better to more or less aggressive camshaft durations check your engine on a rolling road.

The engine timing and fuelling also will say much 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.

Altering your M279 cam will make a dramatic difference to the engine engines power. Choosing a higher performance cam profile raises the engines power accordingly.

NB: Fast road camshafts tend to bump the torque across the rev band, you may lose a little low down torque but high end rpm power will be better.

Competition camshafts, bump the high end rpm power band but as a result the car will not idle smoothly and low end power nearly always suffers.

On a typical daily driver you should ideally to optimize your torque band to your driving style.

You'll never find a M279 Competition cam is a pleasure to live with when driving around busy urban areas.

Stage 1, 2 and 3 mods for the M279

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 M279 parts:

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

Stage 2 M279 parts:

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

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

Stage 3 M279 parts:

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

Review your options and then source your tuning mods and set yourself a power target to avoid disappointment.

ECU mapping will help unlock the full potential of all the upgrades you've done to your M279.

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 results usually rely on the upgrades you've fitted and the condition of your engine.

Turbo modifications on the M279

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 M279.

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

When your motor is fitted with a turbocharger tuning parts are going to net you a larger power gain and you will discover turbo charged engines use stronger components.

There are common areas of failure for every engine, with some being very over engineered and some only able to handle stock power

We recommend you find these limits and fit better pistons and crank to utilize the power.

There are many people spending a lots of money on turbo upgrades on the M279 only to have the M279 catastrophically fail soon after it's used on the roads.

Larger capacity turbo units commonly suffer low end lag, and small turbo units spool up much more quickly but don't have the top end torque gains.

Thankfully the world of turbochargers is always increasing and we commonly find variable vane turbochargers, where the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbochargers divert the exhaust flow into 2 channels and feed these at differently angled vanes in the turbo. They also boost 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 install. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the M279

Don't omit to ramp up the fuel system when you are increasing the bhp and torque - it makes the car more thirsty. We strongly recommend you to be generous with your injector capacity.

The rule of thumb is to add 15% to the flow rate when specifying an injector, helps cope with injector deterioration and provides 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 M279 performance exhaust upgrades

You only need to to uprate your exhaust system with an upgraded one is if your exhaust is creating a restriction in flow.

On most factory exhausts you'll find your flow rate is still fine 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 generally help improve air flow through the engine but avoid an exhaust that is too wide or you may end up will reduce the flow rate. Stick to one and a half to two and half inches as a rule of thumb.

Usual exhaust restrictions can be located the catalysts installed, so adding a freer flowing performance alternative will help avoid this restriction.

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

Faults issues and things to look out for on the M279

Like most engines an M279, 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 M279, failure to do this will exacerbate engine wear, on a tuned M279 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 M279 why not pop over to the forums at TorqueCars where you can chat about M279 tuning options and read about others projects who may be planning to do similar modifications on their M279.

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