BMW M44 Tuning

"All you need to know about tuning the BMW M44 engine!"

Embark on a journey of automotive refinement with the BMW M44 engine, a testament to BMW's commitment to engineering excellence.

This 1.9-liter, inline-4 engine, known for its presence in the BMW 3 Series (E36) and Z3, offers a perfect blend of efficiency and potential for performance enhancements. While it may not boast the larger displacement of its six-cylinder siblings, the M44 is a gem in the world of car tuning and modifications although arguably outshone by the M42 with it's forged components and improved intake.

The M44 stands out with its solid construction and reliable performance, making it an ideal choice for enthusiasts looking to delve into the world of engine tuning.

This engine features advanced technology for its time, such as dual overhead camshafts and BMW's sophisticated Motronic M5.2 engine management system, which optimizes fuel efficiency and engine performance.

What makes the M44 particularly appealing as a project car engine is its versatility and ease of modification. Despite its smaller size, it offers a strong foundation for enhancements.

The engine's compatibility with performance upgrades, such as cold air intakes, performance camshafts, and ECU tuning, makes it a fantastic starting point for those new to car modifications or for those seeking a more manageable project.

Moreover, the M44's robustness and reliability mean that it can handle a variety of modifications without compromising its longevity. While you might not make massive power, most are just seeking a more fun and responsive engine.

This engine is a popular choice in the BMW community, ensuring a wealth of knowledge and aftermarket parts are readily available. Whether it's improving throttle response, increasing horsepower, or simply achieving a more engaging driving experience, the M44 serves as a reliable and adaptable platform.

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History, Power & Specs 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 180 Nm (133 lbft)  at 4,300 rpm

Tuning the BMW M44 and best M44 performance parts.

Best M44 modifications

The top M44 upgrades on an engine are sensibly the ones that give the biggest return for your cash.

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

M44 Performance Camshafts

Upgrading the camshafts in the M44 engine, found in models like the BMW 318is and 318ti, can significantly alter its performance characteristics. The stock intake and exhaust camshafts in the M44 have a lift of 9.7mm, with duration timings of 249° and 257° respectively. For those looking to enhance their engine's performance, there are several aftermarket options available.

Altering the camshaft profile alters the intake and exhaust durations on the engine and can dramatically change the power band and power output.

Performance camshafts for the M44 typically extend the durations and increase the lift. On the intake side, durations can range from 255° to as high as 322°, and on the exhaust side, from 248° to 314°. The lift on these performance cams is also increased, generally ranging from around 10.5mm to 12mm. These changes allow for more air and fuel to enter and exit the combustion chamber, thus creating more power, especially at higher RPMs.

However, it's important to consider the intended use of the vehicle when selecting a camshaft profile. The more aggressive profiles, especially those at the higher end of the duration and lift spectrum, are designed for track use. These cams typically do not perform well on the street as they can lead to a rough idle, reduced low-end torque, and potential drivability issues in everyday driving conditions.

Additionally, it is strongly advised to replace the valve springs when upgrading camshafts, even with mild camshaft profiles. Upgraded valve springs are necessary to handle the increased lift and prevent valve float at high RPMs. Valve float can lead to severe engine damage, so this precaution is vital for maintaining engine reliability.

Several brands offer a good selection of camshafts for the M44 engine. Cat Cams, Piper, and ECS Tuning are notable for their range of options, catering to different performance needs and driving styles. These brands are known for their quality and reliability, ensuring that the upgraded components function well with the engine's characteristics.

In summary, upgrading the camshafts in the M44 engine can provide a substantial improvement in performance, particularly for those seeking enhanced power for track use. However, it's crucial to select the right camshaft profile for your specific needs and to upgrade the valve springs concurrently to ensure engine reliability and performance.

Fast road camshafts usually bump the performance over the rev band, you could sacrifice a little low down torque but higher rpm power will be higher.

For a car driven daily must carefully try to match your power band to your driving style.

Some M44 engines respond better to extreme cam durations so set your engine up on a rolling road.

The engine timing and injectors and fuel pump also have a large bearing 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.

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Best mods for your M44

1. Fast road Camshafts are generally the biggest mechanical mod upgrade, but they must be installed by someone who knows what they are doing and tracking one down can be a challenge but you might find a local firm to regrind a stock camshaft .
2. Air Induction and Performance Exhausts - Note that on their own these mods will NOT ADD POWER in most cases, but they can help enhance power after other mods by losing a restriction.
3. DME Tunes/Remaps - A Remapped M44 ECU provides the most power compared to your outlay, replacement ECUs, and piggyback ECUs are all alternatives.
4. Internal engine mods - crank, pistons, conrods & compression ratio including balancing and blueprinting
5. Upgrades to turbochargers and superchargers - Adding a turbocharger is the most dramatic method to increase air supply, allowing you to combust more fuel and make power gains. Although one of the most challenging mods it does provide the largest gains.
6. Throttle Bodies - controlling the flow and velocity of air entering the engine will help determine the power band and improve performance.
7. Flywheel lightening - a lighter flywheel will improve the engines free revving nature. But not always suitable for all M44 engines.

M44 Tuning Stages

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

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

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

Tuning or remapping the Engine Control Unit (ECU) of the M44 engine, commonly found in BMW models like the 318is and 318ti, can be an effective way to enhance its performance. A well-executed tune can unlock additional horsepower and improve the engine's power delivery, particularly in the mid-range RPMs.

Benefits of a Tune on the M44 Engine:

• A typical ECU tune for the M44 can yield an increase of around 20 horsepower.
• More notably, a tune often provides a significant improvement in power and torque in the mid-range, around 2500 to 4500 RPM. This range is particularly crucial for daily driving, enhancing the vehicle's responsiveness and acceleration in common driving scenarios.
• By adjusting parameters like fuel mapping, ignition timing, and air/fuel ratios, a tune can make the engine more efficient and responsive.
• A tune can also optimize the engine's performance to work in harmony with other modifications, such as upgraded intake or exhaust systems.

Tune or Remap Options for the M44 Engine:

1. Performance Chips:
   • For older M44 engines, a performance chip can be installed. This chip alters the stock ECU programming to increase performance.
   • It's a relatively simple and cost-effective way to enhance power, especially for engines that haven't undergone extensive modifications.
2. Flash Tuning:
   • Flash tuning involves reprogramming the ECU via the OBD (On-Board Diagnostics) port. This method allows for more precise and customized tuning.
   • It's suitable for engines that have been modified, as the tuning can be tailored to the specific changes made.
3. Custom Dyno Tuning:
   • The most personalized option is custom dyno tuning. Here, the car is placed on a dynamometer, and the ECU is tuned in real-time, based on live data from the engine.
   • This method is ideal for achieving optimal performance, especially if the engine has significant modifications.
4. Aftermarket Tuning Solutions:
   • Several aftermarket companies offer tuning solutions for the M44 engine. Brands like Dinan, Turner Motorsport, and BimmerWorld provide tunes that can be easily installed.
   • These solutions often come with pre-set maps that are based on extensive testing and development.

When considering a tune for the M44 engine, it's important to choose the option that best matches your vehicle's modification level and your driving needs. A professional installation and tuning are recommended, especially for more advanced tuning options, to ensure the best performance outcome and to avoid potential engine damage. A well-tuned M44 engine not only provides more power but also enhances the overall driving experience.

It is the main goal to any engine upgrade task to get air into the M44 engine

Intake and exhaust upgrades are common ways to enhance engine performance, but their effectiveness can vary based on the engine type and other modifications. For the BMW M44 engine, these upgrades offer modest gains but can improve the overall driving experience.

Intake Upgrades on the M44:

• Upgrading the intake system in an M44 typically yields a power increase of around 3 to 5 horsepower. Throttle response is improved though.
• This modest gain is due to the already efficient design of the stock intake system. However, an aftermarket intake can improve airflow and potentially enhance throttle response. It is unlikely you will exceed the constraints and limitations of the stock intake.
• Benefits also include a more aggressive intake sound and, in some cases, slight improvements in fuel efficiency.
• It's important to choose a high-quality intake system designed specifically for the M44 to ensure proper fit and optimal performance.

Exhaust Upgrades on the M44:

• Exhaust system upgrades can be broken down into several components: cat-back systems, headers, and rear silencers.

Cat-Back Systems:

• A cat-back exhaust system replaces the stock piping from the catalytic converter to the rear silencer.
• Brands like Magnaflow and Supersprint offer cat-back options that can provide a more aggressive exhaust note and slight performance improvements.
• These systems are usually street-legal as they retain the catalytic converter.

Headers:

• Upgrading the headers can improve exhaust flow right from the engine, potentially leading to better engine performance.
• Aftermarket headers are designed to reduce back pressure, allowing the engine to expel exhaust gases more efficiently.

Rear Silencers:

• Replacing the rear silencer, or muffler, primarily affects the sound of the exhaust. While performance gains are minimal, a quality rear silencer can provide a more satisfying exhaust note.

Legalities of Catalytic Converter Removal:

• Removing or modifying the catalytic converter can lead to increased performance but is often illegal due to emissions regulations.
• In many regions, vehicles are required to pass emissions tests, and tampering with the catalytic converter can result in the vehicle failing these tests.
• It's important to understand and comply with local laws and regulations regarding exhaust modifications.

M44 Turbo upgrades

NA (naturally aspirated) 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

However, when power levels rise, engines will require higher-quality components or they will fail and break. So TorqueCars suggest you install forged components to take advantage of these limitations.

Even with a larger turbocharger, low-end latency is a common problem, whereas tiny turbochargers spool up rapidly but lack the power improvements associated with high-rpm engines.

The exhaust flow from dual scroll turbos is split into two separate channels and pushed through the turbocharger by different-sized vanes. They also boost the engine's ability to scavenge.

When a lot of air is sucked into the engine, the air flow sensor (AFM/MAF/MAP) has a tendency to impede it if it's not used to coping with so much airflow.

Going up you'll find 4 bar air sensors coping with quite large power gains, whereas the OEM air sensor sapped power at a much lower level.

Adding a supercharger or additional turbo will make large torque gains, although more challenging to configure. We have this guide to twinchargers if you want to read more.

Fuelling upgrades on the M44

Don't overlook the need to boost the fuel delivery when you are increasing the torque - it makes the car more thirsty. It is important to over specify your flow rate on the injectors.

The accepted safe increase is to add 20% when specifying an injector, this accounts for injector deterioration and gives a bit of 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.

Stock fuel pressure runs around 40 to 43 psi and should be matched to your power requirements, for most projects on an M44 a simple fuel pressure regulator upgrade will provide enough of a boost and snappy throttle response.

Adding a turbo will obviously make fuel supply an issue so at this point an uprated fuel pump and injector set is recommended.

Performance Throttle Bodies for the M44

Throttle body upgrades are an effective way to enhance the performance of the BMW M44 engine. Individual Throttle Bodies (ITBs) are a particularly popular upgrade among enthusiasts looking to improve engine responsiveness and power.

Benefits of Upgrading to ITBs:

• Improved Airflow: Individual Throttle Bodies provide each cylinder with its own dedicated air source, as opposed to a single throttle body serving all cylinders. This allows for a more direct and efficient airflow into the engine.
• Enhanced Throttle Response: ITBs reduce the air volume between the throttle and the intake valves, resulting in quicker engine response to throttle inputs. This makes the car feel more responsive and agile, particularly at higher RPMs.
• Potential Power Gains: While the exact power increase can vary, ITBs can contribute to noticeable gains in horsepower, especially when combined with other engine modifications like camshaft upgrades or ECU tuning.
• Improved Engine Sound: ITBs often produce a more distinctive and aggressive intake sound, enhancing the auditory experience of driving.

When considering ITBs, it's important to keep a few things in mind:

• Tuning Requirements: Installing ITBs usually requires a re-tune of the engine's ECU to ensure the engine runs properly with the new airflow characteristics. This tuning should be done by a professional familiar with BMW engines and ITB setups.
• Additional Modifications: To fully benefit from ITBs, other engine modifications such as upgraded intake systems, exhaust, and potentially camshaft upgrades might be necessary.
• Cost and Complexity: ITBs are a more complex upgrade than simple bolt-on parts and can be relatively expensive. The installation and tuning process is also more involved, requiring expertise and sometimes custom fabrication.

Upgrading to Individual Throttle Bodies on the M44 engine can significantly enhance its performance, throttle response, and sound. However, it's a comprehensive modification that should be approached with careful planning and professional assistance.

Lighter Flywheels

Installing a lighter flywheel in a naturally aspirated (NA) M44 engine, found in BMW models like the 3series and Z3, can significantly enhance the driving dynamics and response of your motor.

A flywheel is a crucial component in the drivetrain, and its weight plays a significant role in the engine's performance. Here's how a lighter flywheel impacts the M44 engine:

Improved Engine Responsiveness:

A lighter flywheel reduces the rotational mass connected to the engine. This means the engine can rev up and down more quickly, leading to improved throttle response. Drivers often notice this change during rapid acceleration and deceleration, making the engine feel more 'lively'.

With less weight to spin, the engine can direct more of its power to driving the wheels rather than moving the flywheel. This can result in faster acceleration, as the engine reaches its optimal power band more swiftly.

The reduction in rotational mass provides a more direct connection between the throttle input and engine behavior. This results in a more engaging driving experience, especially appreciated during spirited driving or on track days.

Potential Trade-offs:

A lighter flywheel stores less energy at low speeds, which can increase the likelihood of stalling, particularly at lower RPMs. This requires a bit more finesse with the clutch and throttle during takeoff.

The engine idle might become rougher due to the decreased ability of the lighter flywheel to smooth out the natural pulses of the engine's power cycle.

In daily driving situations, such as city driving or in traffic, the car might feel less smooth. This is because a lighter flywheel removes some of the inertia that helps keep the engine turning at lower speeds.

Weak spots Issues & problem areas on the M44

These engines generally prove to be reliable and solid 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.

Headgaskets are prone to fail on these, so keep an eye on coolant and oil levels and look for signs of head gasket problems. Plus don't ever let the engine overheat or you'll fry your gasket.

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.

Regular oil changes are vital on the M44, 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 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.

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This article is flagged for an update, so please pass on specific tips below that I can include. All articles, and content was written by me, Waynne Smith TorqueCars founder. Some outlines are just too general so I appreciate your feedback and suggestions. This entry was filed under BMW. You can leave a response below or join our forum to discuss this article and car modification in detail with our members.

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