Tuning the Mercedes M279

"Comprehensive guide to tuning the Mercedes M279 engine!"

We are frequently getting posts 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 upgrades on this great engine and point out some potential pitfalls along the way.

The Mercedes M279 have loads of potential and with the optimum modified parts like a remap, turbo improvements and camshafts you will really increase your driving experience.

We shall consider M279 tuning and summarise the best mods that work.

The greatest M279 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 M279 parts, they need to be cost effective.

Significant gains on the M279 can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the torque and power output.

NB: Fast road camshafts tend to increase the power across the rpm band, you could drop a little low down power but higher rpm power will be higher.

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

On a car driven daily you need to match your power band to your usage of the car.

I'd never have found a M279 Motorsport cam is a pleasure to live with when driving around busy urban areas.

Some M279 engines respond better to mild camshaft durations check your engine on a rolling road.

The ecu map and fuelling also have a large bearing on the power gains you'll achieve.

Longer valve durations 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.

M279 Tuning Stages

Stage 1 M279 modifications: Sports exhaust manifold, Remaps/piggy back ECU, Fast road camshaft, Drilled & smoothed airbox, Intake headers, Panel air filters.

Stage 2 M279 modifications: Fast road cam, Sports catalyst & performance exhaust, fuel pump upgrades, high flow fuel injectors, Ported and polished head, induction kit.

Stage 3 M279 modifications: Engine balancing & blueprinting, Internal engine upgrades (head flowing porting/bigger valves), Competition cam, Twin charging conversions, Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger).

A remap will help fully realize the full potential of all the mods you've done to your M279.

It will usually give around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but figures achieved may depend much on the mods you've applied and the condition of your engine.

It is the aim to any engine performance tuning project to feed more fuel and air into your M279

Intake headers flow the air from the air cleaner and allow it to be fed into the engine cylinders with fuel for the squish phase.

The size of bore and shape and rate of flow of the Intake headers can make a noticeable difference to to fuel atomisation on the M279.

On popular production engines intake headers are in dire need of aftermarket parts, although a few manufacturers provide reasonably good intake headers.

Big valve conversions on the M279, carrying out port matching and head flowing will also improve torque, & more importantly will permit increasing the torque increase on other tuning parts.

Turbo upgrades for the M279

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 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 major power gains.

When an engine is fitted with a turbocharger parts are simpler to install and you will discover turbocharged engines are made with stronger components.

However every engines have weakspots

It is important to find these limitations and install forged components to handle the power.

There are many tuners spending a lot of money on turbo upgrades on the M279 only to have the whole thing catastrophically fail when it's finished.

Large capacity turbochargers tend to suffer no power at low rpm, and smaller turbochargers spool up much more quickly but do not have the peak rpm torque gains.

Thanks to new tech the market of turbo chargers is always developing and we commonly find 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 a couple of channels and feed these at differently profiled vanes in the turbo charger. They also help the scavenging effect of the engine.

You'll commonly see there's a restriction in the air flow sensor AFM/MAF on the M279 when considerably more air is being drawn into the engine.

We see 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor was restricting bhp at a much lower level.

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

Uprating M279 fuel injectors

When you improve the torque you will need to pay attention to to the fuel delivery.

More torque needs more fuel. It makes sense to over specify your flow rate on the injectors.

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

Best M279 performance exhausts

You only need to to uprate your exhaust if the existing exhaust is actually creating a restriction.

On most factory exhausts you should find that the exhaust flow rate is still fine 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 balance the flow of air through the engine.

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

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

Problems and issues to look out for on the M279

The M279 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the M279, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your M279 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M279 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

We need your help to complete and improve this page, so do give us your feedback in the comments box below.

We really like hearing from our readers, and hearing about which upgrades were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our M279 guides and tips are kept up to date.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under Mercedes. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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