Το γερμανικό coupe σε σχέση με την προηγούμενη χρονιά διαθέτει ένα νέο υγρόψυκτο σύστημα, που σύμφωνα με τους μηχανικούς του M division όχι μόνο αυξάνει την ιπποδύναμη, αλλά παράλληλα μειώνει τη κατανάλωση. Το σύστημα αυτό μειώνει τη θερμοκρασία του αέρα καύσης, με τη BMW να αναπτύσσει μια τεχνική έγχυσης ενός λεπτού ψεκασμού νερού, ο οποίος μειώνει την τάση του κινητήρα να “χτυπήσει” πυράκια, επιτρέποντας έτσι το σημείο ανάφλεξης να γίνει πιο κοντά στην βέλτιστη τιμή.
Κατά συνέπεια, αυτό δημιουργεί μια πιο αποτελεσματική διαδικασία καύσης και την ίδια στιγμή μειώνεται η θερμοκρασία καύσης. Δεδομένου ότι ο ψυχρός αέρας έχει μια υψηλότερη πυκνότητα, η οποία αυξάνει την περιεκτικότητα σε οξυγόνο μέσα στο θάλαμο καύσης, αυτό σημαίνει ψηλότερη πίεση κατά τη διάρκεια της καύσης, κάτι που μεταφράζεται σε βελτιωμένες επιδόσεις και ροπή. Επιπλέον, η μικρότερη θερμική καταπόνηση των εξαρτημάτων αυξάνει και τη διάρκεια ζωής τους.
Το απαιτούμενο νερό αποθηκεύεται σε μια δεξαμενή 5 λίτρων, κατάλληλα μονωμένη για παγετό, και βρίσκεται στο χώρο αποσκευών της Μ4 μαζί με την αντλία νερού, τους αισθητήρες και τις βαλβίδες που ελέγχονται από τα ηλεκτρονικά του κινητήρα. Η αντλία τροφοδοτεί το νερό στα μπεκ με 10 bar πίεση, ενώ ο όγκος του νερού που παρέχεται εξαρτάται από το φορτίο, τις στροφές του κινητήρα και τη θερμοκρασία, προκειμένου να υπάρχει η βέλτιστη κατανάλωση νερού.
Η BMW λέει ότι η δεξαμενή νερού πρέπει να ξαναγεμίζει πριν από κάθε δράση στην πίστα, ενώ σε κανονικές συνθήκες οδήγησης και σε δημόσιους δρόμους εκτιμούν ότι χρειάζεται ξαναγέμισμα μία φορά κάθε πέντε στάσεις για ανεφοδιασμό, χωρίς να απαιτείται καμία επιπλέον συντήρηση. Τέλος, η γερμανική εταιρία αναφέρει ότι το προαναφερθέν σύστημα θα προσφέρεται σύντομα και στο μοντέλο παραγωγής.
H BMW θα εξακολουθήσει να είναι η εταιρία του αυτοκίνητου ασφαλείας για το MotoGP έως τουλάχιστον το 2020.
BMW M – Official Car of MotoGP. Media Guide 2015.
The 2015 season marks the 17th season of BMW M as “Official Car of MotoGP”. Ever since 1999, MotoGP organiser Dorna Sports has been able to rely on a dependable partner in the form of BMW M when it comes to ensuring the highest possible degree of safety at the pinnacle of motorcycle racing. This successful partnership has grown consistently over the years. Last autumn, Dorna Sports and BMW M Division extended their cooperation up to and including 2020. This means we will be able to celebrate the 20th anniversary of BMW M in MotoGP in 2019. We are proud of this partnership, which spans over decades and is extremely rare in international, high-performance sports.
BMW M has always been synonymous with technological innovations, and we are delighted to be able to present another new highlight this year: in the near future, BMW M Division will begin production of a model featuring water injection. Water injection is a system designed to increase the performance and reduce the consumption of combustion engines. We will be using this technology in the BMW M4 MotoGP Safety Car for the 2015 season for the first time.
When it comes to leading a field of high-performance racing prototypes safely in any conditions, technology gleaned from the world of motorsport and innovative ideas are indispensable. That is precisely why BMW M is the “most powerful letter in the world”. The new water injection is just one example of this. Outstanding driving properties and impressive performance parameters – this is what allows our high-performance automobiles to master any challenge, whether on the racetrack or in everyday use.
Millions of fans around the world are captivated by MotoGP. Therefore, it provides us with an outstanding opportunity to present our brand, technology and products to an international audience that is enthusiastic about racing. As well as providing a Safety Car fleet featuring the latest BMW M high-performance models, our commitment to MotoGP also includes many other activities. The BMW M Award, which was presented for the first time in 2003, is a much sought-after accolade among the world’s top motorcyclists. The BMW M MotoGP Experience and our BMW M MotoGP Experts allow us to offer our guests an unforgettable weekend of racing with an exclusive insight into what goes on behind the scenes. As if this were not enough, fans at racetracks around the world also have the opportunity to discover the wide world of BMW M at close hand.
This Media Guide offers you an informative overview of our partnership with Dorna Sports and our commitment to MotoGP, as well as the history of BMW M Division and the company’s extensive range of products. Should you have any further queries, it goes without saying that we are only too happy to help. I hope you have an exciting 2015 season!
Innovative water injection system.
More power and reduced formation of hazardous substances.
Frank van Meel, President of BMW M Division:
BMW M has always been synonymous with technological innovations, and we are delighted to be able to present another new highlight this year: in the near future, BMW M Division will begin production of a model featuring water injection. Water injection is a system designed to increase the performance and reduce the consumption of combustion engines. We will be using this technology in theBMW M4 MotoGP Safety Car for the 2015 season for the first time.“
“The BMW M4 MotoGP Safety Car allows BMW M Division to underline ist innovative prowess and to follow the brand’s philosophy of bringing motorsport technology to the streets. At the same time, the model also offers a clear perspective of an M car that will set a new benchmark in terms of performance, exclusivity and individuality. As well as greater performance coupled with outstanding consumption and emission figures, customers will also benefit from an innovative water injection system with benefits both on the racetrack and in everyday use.”
The mechanism behind water injection in detail.
The performance achievable by a combustion engine is limited by various factors, including the process temperature in the combustion chamber. If this temperature is exceeded, the result is uncontrolled combustion (knocking) and thus a loss in performance and, in the worst case, expensive damage to the engine.
This is particularly important when the engine is charged, as the intake air is already heated intensely in the turbocharger’s supercharger.
An intercooler does ensure that the temperature drops as necessary, but even that has ist physical limits. Depending on design and dimensions of the cooling system and the car’s aerodynamics, the intake air reaches temperatures that are just below the maximum permitted temperatures.
Increasing the supercharging pressure would exceed the knocking limit and is therefore not a viable means for increasing performance. BMW M Division has a solution: injecting a fine spray of water into the collector once more significantly reduces the temperature of the combustion air.
The cooler supercharged air reduces the engine’s tendency to knock, making it possible to bring the point of ignition forward and thus closer to the optimum value. This makes the combustion process more effective, whilst at the same time reducing the combustion temperature. On the other hand, cool air has a higher density which increases the oxygen content in the combustion chamber. This results in a higher mean pressure during the combustion process and in turn optimises performance and torque. Finally, the effective internal cooling of the combustion chamber reduces the thermal strain on numerous performance-related components. This not only prevents damage to pistons, exhaust valves and catalytic converters, but also reduces the strain on the turbocharger, which is subjected to lower exhaust temperatures.
The lower process temperatures also reduce the formation of hazardous substances, in particular nitrogen oxide (NOX). Water injection consequently dramatically improves the effectiveness of the engine.
Using water injection to increase the knocking limit also helps to largely resolve a familiar conflict in objectives when designing powerful engines. Performance and consumption are not least determined by the compression ratio. This also applies, in particular, to highly charged turbo engines like the BMW M TwinPower Turbo, inline six-cylinder. Thanks to a high compression ratio, this engine is highly efficient and boasts low consumption figures, especially in the partial load range. However, the maximum compression ratio is limited by the knocking tendency when fully loaded. Water injection is also hugely beneficial here, as it reduces the tendency for the engine to knock, whilst at the same time increasing the compression ratio. This way, the turbo engine can achieve optimal performance across a wide range of operating points
Implementing the tevchnology in the BMW M4 MotoGP Safety Car.
When positioning the water injection, the engineers at BMW M Division opted for a layout with three injection valves in the plenum chamber, each supplying two cylinders of the six-cylinder, inline engine. This solution ensures very equal distribution and also allows the system to be designed in a compact manner.
Located in the boot of the BMW M4 MotoGP Safety Car is a water tank with a gross volume of about five litres, which houses the water pump, sensors and valves. The pump and complete system of sensors and actuating elements are controlled by the engine electronics, which have been upgraded accordingly. In practice, the pump feeds the water to the injectors at a pressure of ten bar, whereby the appropriate volume is supplied depending on load, engine speed and temperature. This ensures that water consumption is kept to an absolute minimum. In rigorous action out on the racetrack, it is always necessary to refill the water supply whenever the car must refuel. During standard operation, the intervals between water refills are considerably longer, depending on the driving style. Even when driving faster on the motorway, it is only necessary to refill the water container roughly every five stops for refuelling. To ensure the system is as suitable as possible for daily use, it does not require any additional maintenance.
For safety reasons, the BMW M water,injection works with a sophisticated automatic diagnosis. Should the water tank be empty or parts of the system fail, appropriate measures will be taken to protect the power unit. Supercharging pressure and ignition point are cancelled, thus enabling continued operation of the engine without any restrictions other than reduced performance. However, a wide range of measures also ensures the functionality of the system during normal operation. After the engine has been turned off, the water is transported back from the pipeline into the tank, in order to prevent the system components freezing in minus temperatures. The water tank itself is also frost-proof.