Modding upgrading and tuning the Mercedes OM605 engine!

Car tuning tips:OM605 Modifications"

How to modify and upgrade the Mercedes OM605

"Comprehensive guide to tuning and performance parts on the Mercedes OM605 engine!"

Our friends at TorqueCars are frequently seeing threads about how to improve the OM605 from people inquiring about getting more power from the OM605 and wanting to know what are the ultimate OM605 power upgrades. So let us look into Mercedes OM605 tuning mods and outline the best modifications on this great engine and point out some potential pitfalls along the way.

Car Tuning Tips will look into OM605 tuning and report on the best mods that work. Mercedes OM605 have loads of potential and with the ultimate performance tuning mods like remaps, turbo upgrades and camshafts you will positively maximize your driving pleasure.

Just because particular upgrades are popular with OM605 owners it doesn't mean you should fit it, instead we'll focus on the top upgrades that will give your OM605 the best value for money to power increase.

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'.

OM605 induction kits

Improving air intake on the OM605

You need fuel and air for an engine to work. If there is little supply of fuel then it will run lean, if there is insufficient 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 it's important to any engine upgrade project to push fuel and air into your OM605 but this has a knock on effect with the air flow sensor.

You'll commonly see there's a restriction in the air flow sensor AFM/MAF on the OM605 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 torque at a much lower level.

Intake manifolds take the during the engines suck phase from the filter and allow it to be drawn into the engine cylinders.

The size of bore and shape and flow rate of the Intake headers can make a big difference to to fuel atomisation and engine efficiency on the OM605.

It's not uncommon that intake are begging for motorsport parts, although some OEM provide reasonably well designed intake.

Larger OM605 valves, doing some port work and head flowing will also increase bhp and torque, this will make space for raising the bhp and torque increase on other upgrades.

OM605 performance cam tips.

Some OM605 engines respond better to more aggressive camshaft durations check your engine on a rolling road.

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

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.

Significant air intake, and exhaust improvements on the OM605 can be made from cam upgrades. Changing 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 raise the torque across the rpm band, you may lose a little low down bhp but the higher rpm power will be lifted.

Competition camshafts, raise 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 used daily you need to optimize your torque band to your preferences.

I'd never find a OM605 Competition camshaft is a pleasure to live with when in heavy traffic.

Stage 1, 2 and 3 mods for the OM605

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 OM605 parts:

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

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

Stage 2 OM605 parts:

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

Stage 3 OM605 parts:

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

The OM605 units are great to work on and we note that there are plenty of modifications and tuning parts about.

A remap will help release the full potential of all the upgrades you've done to your OM605.

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 may vary depending on the upgrades you've carried out and the condition of your engine.

Turbo modifications on the OM605

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 OM605.

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 an engine is fitted with a turbo upgrades are going to net you a larger power gain and you will discover turbocharged engines will have stronger components.

There are weak spots for every engine, with some being very over engineered and some just sufficiently able to handle stock power

It is important to find these limits and fit higher quality components to survive the power.

There are many guys spending a lots of money on turbo charger upgrades on the OM605 only to see the engine literally blow up just after it's used on the roads.

Big capacity turbos often suffer no power at low rpm, and little turbos spool up much more quickly but won't have the top end bhp gains.

Over the last 20 years the market of turbos is always developing and we commonly find variable vane turbos, allowing the vane profile 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 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 gains, although more challenging to install. We have this in depth look at twinchargers if you want to read more.

Tips about fuel supply on the OM605

You will need to ensure that the engine is not starved of fuel so will need to uprate the fuelling when you start extending past 20% of a torque hike. Experienced tuners recommend to over specify your injector capacity.

The rule of thumb is to add 20% capacity when specifying an injector, this takes into account injector deterioration and provides a bit of 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 OM605 performance exhaust upgrades

We'd only recommend you look to replace your exhaust system with an upgraded one is if the existing exhaust is creating a restriction.

On most factory exhausts you'll find 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 will certainly help air flow from the engine but avoid an exhaust that is too big or you could will reduce the flow rate. Stick to one and a half to two and half inches as a rule of thumb.

The usual suspects causing problems in your exhaust flow rate can be traced to the emissions filters installed, so adding a faster flowing sports 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 OM605

Like most engines an OM605, 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 OM605, failure to do this will exacerbate engine wear, on a tuned OM605 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 OM605 why not pop over to the forums at TorqueCars where you can chat about OM605 tuning options and read about others projects who may be planning to do similar modifications on their OM605.

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