BMW M67 Tuning

"All you need to know about tuning the BMW M67 engine!"

Our aim here is to detail the best approach to M67 tuning and show the premier upgrades. BMW M67 have loads of potential and with the best parts like remaps, turbo upgrades and camshafts you will dramatically improve your driving pleasure.

History, Power & Specs of the Engine

The M68 disel engine used common rail fuel system and turbo V8 design, using double overhead camshafts and 32 valves. It was later replaced by the N57

M67D39 introduced in 1998.

  • 238 PS (235 hp) at 4000 rpm,(413 lbft) at 2000 rpm, with a 4700 rpm redline.
  • 245 PS (242 hp) at 4000 rpm,  (413 lbft) at 1750-2500 rpm, with a 4700 rpm redline.1999

M67TUD40 introduced in 2002.

  • 258 PS (254 hp) at 4000 rpm,  (443 lbft) at 1900-2500 rpm, with a 4700 rpm redline.

M67D44  introduced in 2005.

  • 300 PS (296 hp) at 4000 rpm, 700 Nm (516 lbft) at 1750-2500 rpm, with a 4700 rpm redline.

M67TUD44 introduced in 2006.

  • 330 PS (325 hp) at 4000 rpm, 750 Nm (553 lbft) at 1900-2500 rpm, with a 4700 rpm redline.

Tuning the BMW M67 and best M67 performance parts.

Best M67 mods

Just because particular parts are popular with M67 owners it doesn't mean its worth having, we will highlight only the parts which we have found to be the optimum ie: Those that will give your M67 the best value for money to power increase.

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The camshaft profile plays a big part in the engines power output so camshaft upgrades make quite a large difference. The intake & exhaust durations will alter depending on the chosen camshaft profile, so large engines power gains are on offer for camshaft upgrades.

Fast road camshafts tend to bump the bhp and torque throughout the rev band, you might lose a little bottom end bhp but your high end rpm power will be lifted.

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.

A Race cam is not great driving around busy urban areas. This is because a competition cam causes a very lumpy idle, and makes the car more prone to stall or jerk along in stop start traffic, sadly though many ignore this and end up ruining a perfectly good car and having to revert back to a fast road, or OEM cam profile.

You should ideally optimize your bhp range to your driving style so for a road car stick with a shorter duration M67 cam

Different M67 engines respond better to less aggressive camshaft durations check your engine on a rolling road.

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

Longer 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.

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Best mods for your M67

  1. Tunes - A remap ensures the most power compared to cost, aftermarket ECUs, and inline Tuning boxes are all alternatives.
  2. Flowing and porting the engine head - for larger gains, you will get better flow and make a more efficient engine if you do this to support your other mods.
  3. Forced induction upgrades - Adding a turbocharger is the most efficient approach to increase your intakes air supply, allowing you to use more fuel and make better power figures. It is one of the most challenging upgrades it does provide the largest gains.
  4. Lighter flywheels - a reduced weight flywheel will improve the engines ability to rev freely. In some cases flywheel lightening is not beneficial for all M67 engines.
  5. Air Induction kits and Exhaust - Be aware on their own these mods will NOT ADD PERFORMANCE on most cars, but they can help release power after other modifications by minimizing the restriction.
  6. Fast road Camshafts are significant power adders, but ideally be setup by someone familiar with setting them up on your car and tracking one down may be hard but you might find a local firm to regrind a stock cam .

M67 Tuning Stages

Typical stage 1 mods often include:
Panel air filters, Remaps/piggy back ECU, Sports exhaust manifold, Fast road camshaft, drilled & smoothed airbox, Intake headers.

Typical stage 2 mods often include:
fuel pump upgrades, high flow fuel injectors, Fast road cam, induction kit, Ported and polished head, Sports catalyst & performance exhaust.

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

Plan your options and then acquire your upgrades and set yourself a power target to avoid expensive mistakes.

Remaps will help fully realize the full potential of all the tuning mods you've done to your M67.

(In some cases, as the factory ECU is locked flashing is not an option, so an aftermarket ECU is the route to take, and many of these will outperform factory ECU's but make sure it has knock protection and that you get it setup properly.)

It will usually give you around 30% more power on turbocharged vehicles and you can expect to see around 15% on NASP engines, but power output often differs on the tuning mods you've fitted and the condition of your engine.

Pushing fuel and air into each cylinder is the whole point to any engine upgrade job.

The intake plenum transmit the air from the intake filter and allow it to be drawn into the engine and mixed with fuel.

Design and flow rate of the Intake can make a big difference to fuel engine efficiency on the M67.

On popular production engines plenum chambers are crying out for a performance upgrade, although a few manufacturers provide reasonably well designed plenum chambers.

Fitting big valve kits, carrying out M67 port enlargement and head flowing will also lift bhp, and significantly will allow you to get more from raising the bhp increase on other tuning mods.

Turbo upgrades for the M67

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 M67

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

When an engine has forced induction tuning mods are relatively easy and we find turbo charged engines are made with many forged and stronger components.

However you will find an engines have limits

Research these restrictions and fit higher quality crank and pistons to utilize the power.

We've seen people spending a loads of money on turbocharger upgrades on the M67 only to experience the M67 catastrophically fail just after it's been finished.

Bigger upgraded turbochargers commonly experience a bottom end lag, and small turbochargers spool up really quickly but won't have the high rpm power band gains.

We are pleased that the range of turbo chargers is always developing and we commonly find variable vane turbo chargers, permitting the vane profile is altered according to speed to lower lag and increase top end power.

Twin scroll turbo chargers divert the exhaust gases into two channels and push these at differently designed vanes in the turbo charger. They also help the scavenging effect of the engine.

It is common that there is a limitation in the air flow sensor AFM/MAP on the M67 when loads more air is being sucked into the engine.

We note 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited performance at a much lower level.

Adding a supercharger or additional turbo will make large performance gains, although more difficult to install. We have this article covering twinchargers if you want to read more.

Fuelling Upgrades on the M67

Don't omit to improve the fuel system when you are increasing the torque - it makes the car more thirsty. Don't forget to over specify your flow rate on the injectors.

The accepted safe increase is to add 20% when specifying an injector, this allows for injector deterioration and provides 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.

M67 Exhaust Upgrades

You should look to boost your exhaust if your current exhaust is actually causing a restriction in flow. This is generally not the case on a tune M67 as the factory setup flows really well, and the engine is not a high rpm fuel guzzler anyway.

On most factory exhausts you'll find your flow rate is ok 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 usually air flow out of the engine but avoid an exhaust that is too big or you could very well end up with a reduced flow rate. So generally speaking, keep to 1.5 to 2.5 inches as a rule of thumb.

Common exhaust restrictions can be located the filters (CAT & DPF) installed, so adding a faster flowing race alternative such as a sports catalyst pretty much removes this restriction, thanks to it's larger size and surface area, and will effectively raise the performance to levels you would expect without having a catalyst installed, but keeps the car road legal.

For road going cars mods such as a sports catalyst pretty much remove this restriction, primarily due to it's larger size and surface area, and will effectively raise the performance to levels you would expect without having a catalyst installed.

This keeps the car road legal and will allow the full exhaust flow due to it's higher internal surface area and design. The alternative test pipe mod or cat removal should be considered an off road only mod, as removing a catalyst is illegal in most territories and regions for road registered cars (and in some you can't even replace a working catalyst).

Weak spots, Issues & problem areas on the M67

The M67 engines are generally reliable and solid units, as long as you follow the manufacturers service schedules, and use a good quality oil to ensure longevity. Few problems should happen as long as they are regularly serviced and maintained.

Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines. We have tips on removing carbon build up.

Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.

There is a carbon build up issue thanks to the EGR system so you must avoid short journeys.

Early swirl flaps have been known to break off sending shards into the engine causing major issues, ideally these should be replaced with the later plastic moulded ones with thicker shafts.

Regular oil changes are vital on the M67, especially when tuned and will help extend the life and reliability of the engine.

If you would like to know more, or just get some friendly advice on Tuning your M67 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M67 owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

Please help us improve these tips by sending us your feedback in the comments box below.

We love to hear what our visitors have got up to and which tuning mods work best for you on your car. Which helps us keep our guides and tips up to date helping others with their modified car projects. Your feedback and comments are used to keep this page up to date, and help improve the accuracy of these M67 articles which are continually updated.

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