Our Tuning Development Process

There are many ways to make a car faster, but only a handful are good, safe, reliable and ultimately effective. We take great pride in being one of rare companies who use top notch equipment, extensive, meticulous dyno and road testing and data logging performed by dedicated engineers and tuning experts who are educated continually in order to be up to date with the latest solutions in the industry. If you are looking for tuning for the latest ECU models, you’ll most likely find it here.

How we tune

There are three main aspects of tuning and numerous accompanying elements. The three main parts consist of adjusting the amount of air, the amount of fuel and determining the best moment for ignition.

We’ll use the example of a turbocharged engine as these are most common nowadays and also give the best results when tuning.

The first part of the process is increasing the turbo pressure. In most modern cars this is done using a software tweak. Increasing turbo pressure means that the engine gets more air than it did previously.

However, in order for the engine to perform optimally, the ratio between air and fuel needs to be at a certain level. This is called stoichiometric ratio and it varies for different fuel types. So, adding more air by increasing turbo pressure also means that we need to add more fuel. Having optimal air-fuel ratio greatly improves combustion process, engine reliability and longevity, fuel efficiency and performance. These two changes are the biggest reason why engines get more power after tuning.

However, going too far with them causes serious damage to the engine, gearbox, exhaust system, turbo, numerous sensors and other systems. Knowing the limitations of each part and staying within the boundaries by means of careful testing makes a huge difference.

With these two changes performed, we can move on to adjusting ignition timing. In vast majority of cases, this means advancing it. We’ll get to the intricacies of timing in a minute. Before that, we should explain that advanced ignition timing has several benefits. First of all, it gives more time to the added air and fuel to combust properly, but it also greatly improves throttle response. Even without adding more power, advancing ignition timing would improve drivability, because the car would react to the pedal push more readily.

Still, just like with the turbo and fuel adjustments, advancing ignition too far causes severe mechanical damage to the engine internals and often far more immediate than the damage caused by having too much air and fuel. We cannot stress the importance of testing and data logging enough.

This would be the most basic explanation of how tuning works, but it only explains why cars have more power and torque. As you probably know, the power and torque ratings stated by car manufacturers are their highest values in the rev range, in most cases reserved only for the portion of the power and torque curves. Making a car more capable in a certain, limited part of the rev range is by no means the same as making it more capable overall and noticeably better to drive. This is where the ‘numerous accompanying elements’ come into play.

Small things that make a big difference in tuning

The amount of power that you can gain with tuning depends on a number of elements, including the original state of tune. For example, the four-cylinder OM646 engine used in the W211 Mercedes-Benz E-Class had between 136 and 170 horsepower.  It could be safely tuned to more than 190 hp without any hardware changes. This means that this engine could gain between 12% and 40%, depending on the original tune.

In general, getting between 15% and 30% over the original power and torque ratings is possible for most turbocharged cars without any major mechanical changes.

This kind of a power and torque increase is the result of numerous small adjustments, rather than a huge one. However, the numbers aren’t the only important thing. What is the use of having 700 Nm if they only come when you rev up to 7,000 rpm? The figure looks amazing, but in practice it gives very little to an everyday car. It is important to make the torque and power curves usable in a wide range and not only amazing in a very narrow range.

Which brings us to another thing.

It is very important to note that the rate and nature of adjustments greatly depend on the given context, e.g. rpm at a particular point.

For example, the level of the ignition timing advancement depends on several factors, including the given rpm. At low rpm we advance the timing to give more torque in low revs. As the cylinder pressure grows, we start retarding the timing and when it starts losing power again in high rpm, we advance it a bit more to give it an extra boost in that range. As you can see, the ignition timing adjustment is not just setting a general point, but actually varying it for the best possible output at any point. This results in increased output in rpm sections that usually have a lower torque rating, but also in keeping safety for the sections where cylinder pressures are peaking. So, the torque curve has a much wider range where top torque figure is available, which immensely improves drivability.

Similarly, timing is very important for using the full potential of the energy generated in the cylinders. Imagine you were riding a bicycle and you wanted to get up from your seat and use your body weight together with the full strength of your leg to push on the pedal harder for more acceleration. The actual point where you would do this is very important. If you apply your full power when the pedal is completely down, nothing will happen – you will not move. If you apply it when the pedal is at its highest position, you will waste some of the energy before the pedal actually starts going down. If you apply it before the highest position, the pedal will go back, instead of forwards. The best point would be just as the pedal starts going down after its highest position. However, in order for the full power to be applied at that point, you need to start the preparation earlier. For example, you have to start getting up from your seat before the perfect point for the push.

How does this analogy translate to the internal combustion engine?

The angle of the bicycle pedal at the time of the strongest push does what the angle of the connecting rod in your engine does, so the piston needs to push down on the connecting rod when it is at the exactly right angle.

Now, contrary to the popular belief, the ignition inside the cylinder is not an explosion, but rather a flame front. The spark ignites a molecule of fuel it touches and its ignition then ignites the one next to it, which ignites the next one and so on. These multiple ignitions increase the cylinder pressure in increments and when the cylinder pressure is at its top level, it should be at the exact angle when the connecting rod can give the most benefits – just like the bicycle pedal. However, as we’ve just explained that it takes some time to build up the pressure after the ignition, this means that the ignition needs to start before the actual point when the pressure needs to be at its top level – just like you need to start getting off your seat before the moment when you need to press the pedal.

Getting the perfect timing is of the highest importance for improving performance and keeping safety, but as you can see, it depends on a number of factors.

Similarly, the flame front duration should make it clear why fuel quality also matters. Higher octane fuel burns slower and it gives more controlled combustion, so timing also depends on the fuel used. Many cars today have systems such as knock sensors that automatically give the ECU information to adjust the timing depending on the fuel quality.

As you can see, there are a number of adjustments that, when combined, make a huge difference. However, it is important that all of these work together in perfect harmony, so we make sure that every part of the tuning process is carefully monitored and controlled.

Testing and safety in tuning

A thing often ignored but actually of the highest importance is extensive dyno testing and data logging. Adding more air and fuel will inevitably increase power at some point, but it also creates problems with safety and reliability, just like advancing timing too much can seriously damage the engine internals. What is the point of having more power if you destroy your engine?

When we talk about testing and safety people often assume that this is mostly about keeping torque under the level that would cause problems with the transmission, but it is so much more, including the timing aspect we mentioned above. For example, we also log lambda sensor data to prevent the mixture from becoming too lean, so that we prevent knock from occuring. Similarly, keeping exhaust gas temperature within certain boundaries is very important for preventing damage to the turbo or the exhaust system.

Knowing the limits of car components and meticulously testing while tuning to make sure the car is safe and reliable is paramount. We take great pride in our creations, both regarding their performance and safety and reliability.

As you can see in the pictures of comparing curves of our projects to the original ones in our ‘News’ section articles, the horsepower and torque curves of the original tunings and the ones performed by us have very similar shapes, alongside the considerable increase in figures. This is so in most cases and we wanted it this way because we opted to follow the OEM software architecture, keeping the car completely safe in every respect, while making it far more powerful, responsive and enjoyable to drive.

Going beyond the boundaries

All of the above constitutes only stage 1 tuning. It is designed to make the best use of the potential behind stock OEM parts or some minor additions, as per our clients’ requirements.

However, we can go well beyond that. Knowing the boundaries of stock components after plenty of experience, knowledge and testing allows us to be able to design the perfect course of action for extreme tuning solutions.

Each of these custom projects is special, but some general guidelines say that stage 2 tuning includes adding more capable intake and exhaust parts which help the engine breathe better. These open a bit more room for software adjustments that extract more power while still staying safe.

Stages 3 and beyond include major hardware changes which dictate further additions. In most of these cases we install a more hardcore turbocharger and a number of other parts to accompany this change. Almost any engine hardware change requires careful software modification described in the stage 1 tuning development. This helps us use the full potential of the new parts.

For example, after we add a bigger turbo, injectors in some cars can become insufficiently effective and fail to inject enough fuel, so we need more efficient ones. Intercoolers are also often replaced, even in stage 2. Some cars require replacement of parts such as headers or manifolds, while in the most extreme cases, we may need complete engine rebuild, using more durable engine internals that can deal with extreme increases in pressures.

Depending on the level of tuning, other car parts may need replacement. For example, a car with several hundred new horsepower usually needs bigger brakes, firmer suspension, roll bar and other heavy-duty replacement parts.

As you can see, going beyond stage 2 becomes a much more of a custom tuning job, depending greatly on a number of factors, including customer’s desires and tuner’s guidance. Each addition in the engine operation department gives more room for a change in software management and opens a few new doors. However, as we climb up the performance ladder, the stress that various car and engine parts have to endure greatly increases and calls for additional testing and adjustments. Making a safe and reliable car is as important as making a fast one.

A tuner that can produce good stage 3 tuning has the necessary knowledge of OEM components and limitations to provide top notch stage 1 software tuning without jeopardizing safety or durability. If you’re looking for that, ZIP Tuning is the right place.


Mercedes-Benz GLE 500e Performance Tuning

The downsizing trend mostly has to do with emissions regulations. As new technologies weren’t developing fast enough to match the ever-tightening government requirements, manufacturers had to make the engines smaller in order to make them less damaging to the environment.

However, making engines smaller also often makes them less powerful and, aside from pleasing regulatory bodies, manufacturers also have to please customers who want power on tap.

So far there have been two ways of putting these two worlds together. The first one is reducing the engine size, for example from a V8 to a V6, which makes the car less powerful, but adding one or two turbochargers. Even three in some cases. BMW M550d is an example of this. Also, Mercedes managed to give their latest 4.0 biturbo V8 far more power than in the previous 6.2 l NA V8, despite considerable drop in size.

However, this option is reaching its limits. The second one seems to have more potential. It is using a turbo V6 instead of a V8, but adding an electric motor to the mix. It increases the power, gives instant torque, reduces emissions and fuel consumption and matches and often exceeds performance merits of the V8.

A great example is the Mercedes-Benz GLE 500e. Being a 500, one would assume it’s a V8, but the ‘e’ shows it’s a hybrid. However, the 500 moniker is rightfully used, as this car gives the power of a V8 with the unprecedented green credentials. The power now comes from a combination of a turbo 3 l V6 and an electric motor. The combined power rating stands at 422 hp and massive 650 Nm of torque and the V6 alone gives some 329 hp. Another big benefit of the hybrid powertrain is that the electric motor delivers all its torque from 0 revs. This makes hybrids with good motors very responsive, although the weight of batteries somewhat diminishes the benefit. The GLE 500e weighs about 2,500 kg, for example.

GLE 500e tuning

Despite the weight, the standard car reaches 100 in respectable 5.3 seconds and allows for an emissions free ride of up to 30 km and with speeds up to 130 km/h. Pretty handy, right?


Can you tune hybrid cars?

Yes! The whole system needs to work well together and it requires expertise, experience and top of the line testing equipment.

We have all that. We have already tuned many hybrid cars, including a very interesting BMW 330e iPerformance and Porsche Panamera Hybrid for the first season of National Geographic’s Supercar Megabuild series. The latter alone should show the expertise we boast.


Tuning Mercedes-Benz GLE 500e

The tuning we developed for this particular car includes changes to the amounts of air and fuel sent into the engine, as well as an adjustment in ignition timing. All these changes need to work well together and also complimented the hybrid powertrain so extensive testing and data logging is of the highest importance.

First of all, we increased the turbocharger pressure for the internal combustion V6. This modification increased the amount of air that the engine is fed. The additional air needs to be followed by an adjustment in the amount of fuel that is sent into the cylinders. This is so because having proper air-fuel ratio improved combustion, longevity and performance.

It is also very important to know what the limitations are to every engine and its surrounding components. Going too far can cause serious damage. We never exceed safety limitations.

The final part of these adjustments is adjusting the ignition timing. Ignition timing is advanced in order to provide better combustion and more immediate throttle response. Combined with the instant torque delivery of the electric motor, the added power from the tuning and the improved throttle response, it is remarkable just how well the GLE 500e reacts to every push of the pedal.

As already explained, simply adding more power to the internal combustion unit is not enough. The entire hybrid system needs to work in unison across the rev range and the combined power output needs to reflect that.

As you can see in the images below, we had two sets of changes for this tuning process.

The first one increased the overall power rating to 490 horsepower and 724 Nm of torque. We saw room for some minor tweaks and have another go at tuning the GLE 500e. The final result came to 514.8 horsepower and 764 Nm of torque.

GLE 500e tuning curve
First tune
GLE 500e tuning
Second tune


More adjustments for better results

The three previously explained adjustments (fuel, air and ignition timing) hide many more intricacies, especially the latter. The figures above show the highest power and torque ratings within the rev range. However, when driving a car, you are not always in the top rpm position. In fact, in everyday conditions, you’re rarely or never there.

This is why it is important to make the car drivable and the power and torque available in as wide a range as possible. This is where extensive testing and fine tuning play the biggest role.

For example, while adjusting ignition timing for this car, we don’t simply advance it to the same level for the entire rev range. For low rpm sections we advance timing in order to give the car more boost in the rev range where it usually lacks push. As we approach rpm that has more torque in stock setting, we retard the timing a bit so as to preserve safety. Higher in the rev range, as the torque figure starts to drop again, we advance timing once again to give it a rise. All these put together mean that the Mercedes GLE 500e gets a wider torque curve which it can use effectively in everyday driving without any worries of causing damage or reducing durability and reliability of the car.

Getting the best possible timing is also very important for using the energy efficiently. Combustion inside the engine is not an explosion, but a flame front, which means that it spreads and increases the pressure inside the cylinder as it does so. This spreading is very fast, but it does require some time.

For this Mercedes we performed multiple tests to find just the perfect moment for ignition – the moment when the mixture would ignite and start increasing pressure and then reach the top pressure exactly when the engine can make the best use of the force generated. This is the point at which connection rod inside the engine can transmit the largest amount of energy to the crankshaft.

Basically, we targeted this point by starting the ignition earlier and building up the pressure inside the cylinder making it reach the highest level at that exact point.

GLE 500e tuning

Testing and safety

We have mentioned the importance of testing and safety several times, but it really can’t be stressed enough. The above paragraphs gave you a better insight into our tuning process for this car, but getting the information necessary for such precise modifications can only come from plenty of tests and extensive data logging.

However, gathering this information isn’t the most important thing at all. While testing and data logging, we could carefully monitor the stress levels and temperatures generated throughout the combustion process. For example, logging lambda sensor data allowed us to make sure we will never cause engine knock.

Measuring the temperature of the exhaust gas enabled us to prevent any chance of causing damage to the turbocharger and the entire exhaust system.

Having information and experience with the drivetrain allowed us to be sure that torque levels would never exceed the limits that the gearbox can endure.

Even if we decided to neglect safety for some reason (and we never do that), testing is very important because there is no way to produce top quality tune without gathering information that only testing can give. Tuning without testing is a terrible idea as you can imagine what the possibility is of making all of the above perfect by guessing the values. NONE!

This also lets us make the car more powerful than other tuners. We know the safe limits and we can approach them with confidence knowing we will never cause damage. The ones who neglect extensive testing always need to go well below the boundaries to be sure that they won’t destroy your engine. This gives less power and torque, while at the same time not guaranteeing safety.

Exactly the opposite of what we do!

Tuning for BMW 330e iPerformance

After a very successful project we developed for National Geographic’s show Supercar Megabuild where we developed the tune used to make a sensible Porsche Panamera Hybrid a proper supercar, we’ve been getting more and more requests for tuning hybrids and our latest creation is this BMW 330e iPerformance.

Tuning hybrids requires a somewhat different approach to the one used on cars with internal combustion powering system only. Beating the challenge of complementing the original software architecture and making it operate perfectly with the electric motor has been a highly rewarding experience and we’ve established ourselves as experts.

The fact that this is BMW’s fourth plug-in car was very important for us. It meant that it comes from a decent line of development and tests. Now, we have no doubt that BMW has a remarkable development team and that they thoroughly test their cars, but simply put, there is no way that any tests could replace years of on-road experience gathered from thousands of customers in different locations.

Well, the 330e iPerformance came after all that done with the likes of the i3, i8 and X5 xDrive40e.

The car we started with had a 2.0 l internal combustion petrol engine and an electric motor. The petrol unit produced 180 hp and 291 Nm of torque, while the electric motor added another 87 hp and 250 Nm of instantly available torque at any revs. This is an inherent feature of electric motors and it makes the world of difference for the driving feel.

The electric motor is cleverly placed into the housing of the Steptronic Sport gearbox and the combined system power and torque figures stand at 252 hp and 420 Nm of torque. It may not seem like much, but it is actually a very good drive – and a sensible one at the same time.

For example, the car reaches 100 in 5.9 seconds and has the top speed of 225 km/h. Its electric only range is not huge – floating between 22.5 km and 40 km at speeds up to 120 km/h depending on the testing cycle – but this also means that the battery is smaller, lighter and there to help effortlessly, rather than give more autonomy but also hamper driving dynamics with massive weight of larger battery packs.

Yes, even in a sensible hybrid BMW did not forget driving dynamics and performance. The official average fuel efficiency stands at about 2 l per 100 km, which is amazing for a sedan with about 250 hp that costs less than a groundbreaking fortune.

The electric tech came directly from highly praised i3 and i8, while the engine is a TwinPower turbo machine which managed to snatch the International Engine of the Year Award twice. So, basically, this powertrain is a mixture of two thoroughly tried and tested systems that work together like a charm.

BMW 330e tuning

Tuning BMW 330e iPerformance

We do offer additional tuning stages for the BMW 330e, but this particular customer felt that our Stage 1 tuning resulted in more than satisfying gains. Here is what we did.

For this project, we started off with a change in turbo pressure which resulted in sending more air to the combustion chambers. After this, we readjusted fuel delivery to complement the additional air and make the most of stoichiometric ratio.

This has to be done with care and alongside extensive testing, as having efficient air-fuel ratio throughout the rev range is one of the most important aspects of any internal combustion engine’s operation.

This brought significant improvement in the power department, but we’ll get to the numbers in a minute. Before that, we found room for another improvement which did not greatly increase power per se, but made a huge difference in the driving feel.

Namely, we advanced ignition timing. It helps the additional air and fuel combust better and also improves throttle response. This was actually one of the first things that the customer noticed. The car reacts to the throttle push instantaneously.

However, advancing the ignition too far is very dangerous for the engine. That operation requires expertise, needs to be done carefully and needs to be tested during the process. This is why our experience, equipment and dedication are paramount.

Just as an example of what this part of the tuning process includes, let us tell you what we did during the ignition timing adjustment.

The timing is not the same throughout the rev range. As you probably know, every engine exerts top power and torque levels at a limited rev range. This rev range is always towards the middle of the rpm array. The wider the torque curve, the more available the torque. Modern cars have a wider torque curve, but we managed to widen it even further, making BMW 330e driving experience noticeably better.

How did we do this?

In low revs we advanced ignition timing in order to improve throttle response and increase torque. Of course, we needed extensive testing to make sure we advance it as much as possible for maximum results, but not go too far as that would cause engine damage.

As the revs increase and the pressures inside the cylinder rise, we start retarding ignition to prevent going too far and damaging anything. As we get past this point and the torque starts dropping again, we advance the timing again to give the car more push in that section as well.

This way we managed to improve drivability in a very wide rev range and preserve safety at times when cylinder pressures reach maximum levels.

Also, we make sure to set the timing in a way that we make the best use of the energy generated inside the engine. When a spark ignites the air-fuel mixture in the cylinders, it spreads the flame and gradually increases cylinder pressure. For maximum results, we needed to set up the ignition timing so that it builds up the pressure and reaches its maximum value exactly when the connecting rod is at the angle that allows it to make the best use of the energy.

This segment alone should show you the importance of testing and data logging, not only in terms of safety, but also making the most of the available performance figures.


So, what are the figures?

BMW 330e tuning curve

The ZIP tuned BMW 330e iPerformance now has 307 hp and massive 477 Nm of torque. This is with no hardware changes, just our meticulously precise software adjustment. We can develop tunings for at least two more stages for the 330e, the second one including intake and exhaust parts improvements and the third one using more capable turbochargers, intercoolers, injectors and other accompanying parts.

Aside from the top power and torque figures, we are especially proud of the smooth delivery across the rev range and greatly improved drivability in everyday conditions.

If you have a BMW 330e and you wish to make it noticeably better, but also completely safe and as reliable as ever, feel free to contact us and let us open a whole new chapter for you and your car.