Tuning the Mercedes M177

"Comprehensive guide to performance tuning the Mercedes M177 engine!"

We are regularly seeing threads about the things we recommend when it comes to M177 power upgrades. So let us look into Mercedes M177 upgrades and outline the best modifications on this great engine and point out some problems along the way.

The Mercedes M177 make awesome project engines and with carefully chosen modifications like a remap, turbo improvements and camshafts you will really increase your driving fun.

We shall review and look at M177 tuning and report on the greatest modifications.

Just because particular upgrades are appear in lots of M177 projects it doesn't mean you should fit it, we will concentrate) on the top upgrades that will give your M177 the best value for money to power increase.

Significant gains on the M177 can be made from cam upgrades. Altering the cam profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road camshafts tend to push up the bhp through the rpm range, you might lose a little bottom end power but your high end rpm power will be lifted.

Motorsport camshafts, push up 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 road car you need to optimize your engines power to your cars usage.

I'd be gobsmaked if you have found a M177 Competition cam is a pleasure to live with when in heavy traffic.

Different M177 engines respond better to mild camshaft durations than others.

The ECU mapping and fuel pump and injectors also will say much on the bhp gains you'll hit.

Altering 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.

M177 Tuning Stages

Stage 1 M177 modifications: Panel air filters, Sports exhaust manifold, Remaps/piggy back ECU, Drilled & smoothed airbox, Intake headers, Fast road camshaft.

Stage 2 M177 modifications: Ported and polished head, fuel pump upgrades, high flow fuel injectors, Sports catalyst & performance exhaust, Fast road cam, induction kit.

Stage 3 M177 modifications: Internal engine upgrades (head flowing porting/bigger valves), Engine balancing & blueprinting, Crank and Piston upgrades to alter compression, Adding or Upgrading forced induction (turbo/supercharger), Twin charging conversions, Competition cam.

The M177 power trains respond well to upgrades and we see that there are plenty of parts and tuning parts out there.

Remaps will help unlock the full potential of all the upgrades you've done to your M177.

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 usually depend much on the upgrades you've carried out and the condition of your engine.

Forcing more fuel and air into the M177 engine is the whole point to any engine upgrade job.

Intake headers take the air during the suck phase from the air cleaner and allow it to be drawn into the engine and mixed with fuel.

Structure and flow characteristics of the Intake manifold can make a substantial improvement to fuel mixing and power on the M177.

Commonly we find the intake manifold are needing motorsport parts, although a few makers provide well optimised intake manifold.

Adding a M177 larger valve kit, carrying out port matching and head flowing will also boost performance, and significantly will give you a better performance increase on other tuning mods.

Turbo upgrades for the M177

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 M177

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 the engine is fitted with a turbocharger modifications are going to make more power and turbo engines are made with better components.

However most engines have weakspots

Discover these restrictions and fit better quality components to utilize the power.

It's not unheard of mechanics spending a lot of money on turbo upgrades on the M177 only to have the whole thing catastrophically fail on it's first outing after it's finished.

Big capacity turbochargers tend to experience no power at low rpm, and small turbochargers spool up much more quickly but do not have the peak rpm engines power gains.

In recent times the market of turbos is always improving and we are seeing variable vane turbos, where the vane angle is altered according to speed to lower lag and increase top end power.

Twin scroll turbos divert the exhaust gases into a couple of channels and feed these at differently angled vanes in the turbocharger. They also improve the scavenging effect of the engine.

You'll commonly see there is a limit in the air flow sensor MAF/MAP on the M177 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 sapped bhp and torque at a much lower level.

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

Uprating M177 fuel injectors

When you boost the bhp and torque you will need to increase to the fuel delivery.

More bhp and torque needs more fuel. We would recommend you to be generous with your flow rate on the injectors.

As a rule of thumb add 20% when specifying an injector, this takes into account injector deterioration and affords some 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.

Best M177 performance exhausts

Only look to boost your exhaust if your current exhaust is actually creating a restriction in flow.

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.

Sports exhausts generally help improve air flow through the engine but do not go too big or you could will reduce the flow rate. Stick to 1.5 to 2.5 inches as a rule of thumb.

Common exhaust restrictions are traced to the catalyst and filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Problems and issues to look out for on the M177

The M177 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the M177, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your M177 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M177 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

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We really like hearing from our readers, and hearing about which parts were the most effective for them, it helps us improve our recommendations and articles to reflect current trends in modifications and ensures that our M177 guides and tips are kept up to date.

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