Tuning the BMW M41D17

"Comprehensive guide to performance tuning the BMW M41D17 engine!"

This pages aim is examine the options for your M41D17 tuning and outline the optimum mods that work. BMW M41D17 provide a fun base for your project and with the right tuning mods like remaps, turbo kits and camshafts you will really enhance your driving enjoyment.

The best M41D17 modifications on an engine are obviously the ones that give the best value for money.

We won't be swayed by popular M41D17 modifications, they need to be cost effective.

Significant gains on the M41D17 can be made from camshaft upgrades. Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

NB: Fast road camshafts normally raise the bhp and torque across the rpm band, you may lose a little low down torque but higher rpm power will be higher.

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

A Motorsport camshaft is not great driving in heavy traffic.

You should ideally match your power band to your driving style so for a car used daily stick with a shorter duration M41D17 camshaft

Different M41D17 engines respond better to different cam durations so set your engine up on a rolling road.

The ECU mapping and fuelling also have a large bearing on the power gains you'll hit.

Altering 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.

The M41D17 engine blocks are great to work on and we note that there are plenty of parts and performance parts around.

Mapping will help to establish the full potential of all the upgrades you've done to your M41D17.

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.

It is the aim to any car tuning task to force more air into the M41D17 engine

The intake plenum take the air during the suck phase from the intake filter and allow it to be drawn into the engine cylinders.

The shape and flow characteristics of the Intake can make a large improvement to fuel atomisation on the M41D17.

On popular production engines air intake manifolds are begging for motorsport parts, although some OEM provide reasonably well designed air intake manifolds.

Fitting big valve kits, doing a bit of port matching and head flowing will also raise torque, & more importantly will permit a better torque increase on other tuning mods.

Turbo upgrades

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 M41D17

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

If a car is turbocharged, parts are simpler to install and we find turbo engines are built using more solid components.

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

See where you'll find these limits and fit more solid crank and pistons to utilize the power.

We've seen guys spending a lot of money on turbo upgrades on the M41D17 only to experience the M41D17 literally blow up when it's first rolling road session.

Larger capacity turbo chargers often suffer no power at low rpm, and low capacity turbo chargers spool up really quickly but don't have the peak rpm bhp gains.

Thanks to progress the world of turbochargers is always moving on and we commonly find variable vane turbochargers, permitting the vane profile is altered according to speed to lower lag and increase top end torque.

Twin scroll turbochargers divert the exhaust flow into a couple of channels and push these at differently profiled vanes in the turbocharger. They also boost the scavenging effect of the engine.

You'll commonly see there's a limitation in the air flow sensor AFM/MAP on the M41D17 when loads more air is being drawn into the engine.

You'll see that 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor limited power at a much lower level.

Adding a supercharger or additional turbo will make large bhp and torque gains, although harder to setup. We have this feature on twinchargers if you want to read more.

Fuelling upgrades and mods

When you improve the power you will need to uprate to the fuel system.

More power needs more fuel. It is important to be generous with your flow rate on the injectors.

As a rule of thumb add 20% to the flow rate when buying an injector, helps cope with injector deterioration and provides 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.

Exhaust upgrades and mods

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

On most factory exhausts you'll find the exhaust flow rate is still 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 can help increase the flow of air through the engine.

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

Common exhaust restrictions can be located the filters installed, so adding a higher flowing race alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the M41D17

The M41D17 engines, if regularly serviced and maintained, are generally very reliable and have few issues.

Regular oil changes are vital on the M41D17, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your M41D17 engine please join us in our friendly forum where you can discuss tuning options in more detail with our M41D17 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 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 M41D17 guides and tips are kept up to date.

History of the Engine


66 kW (90 PS; 89 hp)@4,400 190 N⋅m (140 lbft) @2,000

Tuning the BMW M41D17 and best M41D17 performance parts.

Best M41D17 upgrades

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

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

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


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