Modding tuning and best performance upgrades on the Mercedes M297 engine!

All you need to know about "M297 Modifications"

M297 Modifications Guide

How to modify and upgrade the Mercedes M297

"Comprehensive guide to performance tuning the Mercedes M297 engine!"

Sites like TorqueCars are frequently getting emails about how to improve the M297 from people wanting to know what are the best M297 mods that work. So let us look into Mercedes M297 upgrades and outline the best modifications on this great engine and point out some problems along the way.

The Mercedes M297 are popular engines and with carefully picked uprated mods like ECU maps, turbo upgrades and camshafts you will dramatically increase your driving experience.

In this article we review and look at M297 tuning and provide tips on the ultimate upgrades.

Just because particular modifications are popular with M297 owners it doesn't mean its worth having, instead we will concentrate on the ultimate modifications that will give your M297 the best power gain for you spend.

Without us subscribing to the misaprehension 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'.

M297 induction kits

Improving air intake on the M297

You need fuel and air for an engine to work. If there is not enough fuel then it will run lean, if there is little flow of air it runs rich losing 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 Pushing air into the M297 engine is the main goal to any engine performance tuning project.

You'll commonly see there is a limit in the air flow sensor AFM/MAP on the M297 when considerably more air is being fed into the engine.

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

Engines intake headers transmit the during the engines suck phase from the intake filter and allow it to be pulled into the engine cylinders.

Design and flow characteristics of the Intake headers can make a big difference to to fuel mixing and power on the M297.

We often see intake are improved through performance upgrades, although a few OEM provide well optimised intake.

Adding a M297 larger valve kit, carrying out port matching and head flowing will also boost bhp, & more importantly will give you a better bhp increase on other upgrades.

M297 performance cam tips.

Different M297 engines respond better to mild cam durations than others.

The engine timing and fuelling also will make differences on the torque gains you'll achieve.

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.

Significant air intake, and exhaust improvements on the M297 can be made from camshaft upgrades. Changing the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the engines power and power output.

NB: Fast road cams commonly boost the torque across the rev range, you may sacrifice a little low down power but your higher rpm power will be better.

Motorsport cams, boost 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 is not great in heavy traffic.

You should ideally optimize your engines power to your preferences so for a car used daily stick with a mild fast road M297 camshaft

Stage 1, 2 and 3 mods for the M297

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 M297 parts:

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

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

Stage 2 M297 parts:

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

Stage 3 M297 parts:

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

The M297 engine blocks respond well to mods and thankfully there are increasing numbers of mods and performance parts about.

A remap should help to to establish the full potential of all the modifications you've done to your M297.

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 figures achieved may vary depending on the modifications you've fitted and the condition of your engine.

Turbo modifications on the M297

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 M297.

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.

If a car has a turbo already fitted parts are simpler to install and we find turbo charged engines will have many forged and stronger components.

There are practical limits for every engine, with some being over specified and some only just able to handle stock power

Discover these limitations and upgrade to better quality crank and pistons to handle the power.

We see many guys spending a fortune on turbo upgrades on the M297 only to experience the M297 go up in smoke just after it's been enthusiastically driven.

Bigger capacity turbo units commonly suffer low end lag, and smaller turbo units spool up quickly but don't have the peak rpm torque gains.

Thanks to new tech the market of turbos is always evolving and we now see variable vane turbos, permitting the vane angle is altered according to speed to lower lag and increase top end bhp.

Twin scroll turbos divert the exhaust flow into 2 channels and direct these at differently angled vanes in the turbo. 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 power gains, although more difficult to configure. We have this feature on twinchargers if you want to read more.

Tips about fuel supply on the M297

Don't omit to boost the fuel system when you are increasing the power - it makes the car more thirsty. Experienced mechanics will tell you to be generous with your injector capacity.

The rule of thumb is to add 15% capacity when buying an injector, this allows for injector deterioration and gives 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 M297 performance exhaust upgrades

Only look to improve your exhaust system with an upgraded one is if your exhaust is actually creating a restriction.

On most factory exhausts you'll find the flow rate is ok 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 can usually air flow through the engine but do not go too large or you could will reduce the flow rate. Stick to one and a half to two and half inches as a rule of thumb.

Typically exhaust restrictions come around the catalyst installed, so adding a freer flowing sports alternative will help avoid this restriction.

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

Faults issues and things to look out for on the M297

Like most engines an M297, 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 M297, failure to do this will exacerbate engine wear, on a tuned M297 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 M297 why not pop over to the forums at TorqueCars where you can chat about M297 tuning options and read about others projects who may be planning to do similar modifications on their M297.

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