Tuning the BMW M44

"Comprehensive guide to tuning and performance parts on the BMW M44 engine!"

The BMW M44 have loads of potential and with the ultimate modified enhancements like a remap, turbo improvements and camshafts you will certainly maximise your driving pleasure.

Let us consider M44 tuning and show the premier upgrades.

The best M44 mods on an engine are as we have found the ones that give the biggest return for your cash.

We won't be swayed by popular M44 mods, they need to be cost effective.

Altering your M44 camshaft will make a dramatic difference to the engine power band. Choosing a higher performance camshaft profile raises the power band accordingly.

NB: Fast road cams commonly boost the bhp across the rev band, you could drop a little low end torque but the high end rpm power will be better.

Race cams, boost the high end 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 one should, ideally, try to optimize your bhp range to your cars usage.

I'd be amazed if you have ever thought a M44 Motorsport and race camshaft is a pleasure to live with when driving in heavy traffic.

Each engine responds better to more or less aggressive camshaft durations check your engine on a rolling road.

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

A longer valve duration 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.

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Guide to the BestM44 Tuning Mods & Upgrades

  1. Mods that Remove a Restriction

    A restricted intake or exhaust will have an impact on your car's performance, so use an induction kit/filter upgrade and better flowing exhaust whenever your tuning creates a flow restriction.

  2. Fit Stronger Parts

    Tuned cars will show up weaknesses, typically in the turbochargers, clutch and internal engine components. Whilst most engines can cope with mild tuning mods, TorqueCars recommend that you upgrade the internal components before these weak spots manifest themselves.

  3. ECU Tunes & Remapping

    While some cars can be easily remapped, others may require piggyback ECU's or aftermarket ECU's but this is the most vital step of your tuning project as it fully releases the power from all of your mods and upgrades. Expect 10-20% on NASP engines and 30-40% on turbocharged units.

  4. More Power Needs More Fuel & Air

    Every tuning project will aim to increase the air supply, but fuel supply is just as vital and will need to match the air the engine can utilise. Fuel to Air ratio is vital so upgrade the fuel pump & injectors. Also you can look to perform head mods (flowing and porting), bigger valves, fast road cams and forced induction upgrades to improve fuel.

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

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

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

The M44 engines make great tuning projects and thankfully there is a growing number of modifications and performance parts around.

ECU flashing helps fully realize the full potential of all the upgrades you've fitted to your M44.

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 often rely on the upgrades you've applied and the condition of your engine.

Getting fuel and air into each cylinder is the aim to any engine upgrade project.

Intake manifold take the air during the suck phase from the intake filter and allow it to be fed into the engine and mixed with fuel.

Design and rate of flow of the Plenum can make a large improvement to fuel delivery on the M44.

Most headers are improved through aftermarket parts, although a few car makers provide fairly well optimized headers.

Big valve conversions on the M44, carrying out port matching and head flowing will also raise power, & more importantly will permit increasing the power increase on other tuning parts.

M44 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 M44

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 your car has a turbocharger mods are more reliable and you'll see that turbo engines will have harder and stronger components.

However you'll find engines will need better parts at higher power limits

See where you'll find these restrictions and upgrade to forged components to handle the power.

It's not unheard of car owners spending a lot of money on turbocharger upgrades on the M44 only to experience the M44 throw a rod when it's used in anger.

Big upgraded turbos tend to suffer low end lag, and small turbos spool up quickly but don't have the high rpm torque gains.

Thanks to new tech the choice of turbos is always evolving and we are seeing variable vane turbos, where the vane angle is altered according to speed to lower lag and increase top end torque.

Twin scroll turbos divert the exhaust flow into two channels and flow these at differently angled vanes in the turbo charger. They also increase the scavenging effect of the engine.

It is common that there's a restriction in the air flow sensor AFM/MAP on the M44 when a lot more air is being pulled into the engine.

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

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

M44 Fuelling Upgrades and Mods

Don't omit to ramp up the fuelling when you are increasing the torque - it makes the car more thirsty. It is important to be generous with your injector capacity.

The accepted safe increase is to add 20% capacity when buying an injector, which takes into account injector deterioration and affords you 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.

M44 Exhaust Upgrades and Mods

You should look to uprate your exhaust if your exhaust is actually creating a restriction.

On most factory exhausts you should find that the flow rate is still fine even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust.

Note that with the biggest exhaust you can find this will slow up the exhaust flow rate - the best exhausts for power gains are usually between 1.5 to 2.5 inches. It is the shape and material more than the bore size.

Typically exhaust restrictions come around the catalyst and filters installed, so adding a better flowing high performance alternative will help avoid this restriction.

Weak spots, Issues & common problem areas on the M44

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

Regular oil changes are vital on the M44, particularly when the engine has been modified and is putting down more power than the manufacturer intended.

For more information on Tuning your engine please join us in our friendly forum where you can discuss M44 tuning options in more detail with our owners. It would also be worth reading our unbiased tuning articles to get a full grasp of the benefits and drawbacks of each modification.

History of the Engine

The M44 is a DOHC four-cylinder petrol engine which replaced the BMW M42

  • M44B19 from 1996-2000
    1,895 cc (115.6 cu in)
  • 103 kW (138 bhp) at 6,000 rpm 180Nm(133 lbft)  at 4,300 rpm

We need your help improving this article, so please send us your feedback in the comments box below and pass on any tips, points or facts we have wrong or have not covered.

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 guides and tips are kept up to date.


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