As chip tuning the subsequent increase of the efficiency of colloquially car - (combustion) engines by selectively changing the factory-set control parameters of the electronic engine management system called.
In so-called chip tuning, targeted interventions in the application of the engine electronics are used to increase the boost pressure of the engine supercharging and the amount of fuel to be injected into the combustion chamber. As a result, engine output and torque are increased without mechanical intervention in the unit or having to replace components. No structural changes are therefore made to the engine; the increase in performance is based solely on exhausting the thermodynamic and mechanical reserves that, according to chip tuners, every series combustion engine has at its disposal . As a consequence, this type of chip tuning can lead to a not inconsiderable output of extra power to the drive train, particularly in the case of exhaust gas turbocharged engines. Such an increase in performance can be observed in particular in the case of exhaust-gas turbocharged diesel engines: In addition to the increase in the achievable maximum speed and the tractive power of the vehicle, a considerable improvement in the acceleration values and a sensitization of the engine response behavior during the acceleration process and load changes can be determined. This can u. a. can be attributed to the fact that the so-called boost range of the exhaust gas turbocharger is reached in an earlier speed range due to the higher boost pressure and is only exhausted in a higher speed range. The technical effects regarding durability, reliability and proportionality in comparison to the factory setting of a unit are controversial and not finally clarified. To illustrate these reserves, it is stated that some engine manufacturers have started to manufacture several engines on the same basis, but with different performance data. In fact, however, some of the more powerful models are built with components with significantly higher strength (through the use of higher-quality materials) but geometrical equality. This makes such machines appear particularly attractive for tuning. Despite the same main dimensions, these engines are different. The argument often used by tuning companies that the same engine would be available with a higher series output is usually simply wrong.
For example, the 110- differ kW - (150- PS -) variant of the VW -1,9-l- TDI engine and the 85 kW (115 horsepower) variant with a modified crankshaft , modified connecting rod , piston with higher top ridges , a cooled exhaust gas recirculation and a more powerful turbocharger despite the same main dimensions. Therefore, it often happens that dubious providers in particular overstrain any engine reserves.
In order to assure their customers that this is not the case with their range of services, reputable chip tuners provide a guarantee on the engine and transmission or damage to the engine or vehicle up to a certain mileage (usually 100,000 km) or vehicle age (max. 3 years). Gearboxes that can clearly be traced back to chip tuning. However, this clear evidence is often very difficult to provide. In the event of damage, it is usually difficult to determine how a defect ultimately occurred, so that in the end the vehicle owner bears the costs. Tuning providers and vehicle manufacturers will not admit any technical errors on this point. The vehicle user should be aware of this warranty issue.
The parameters of the electronic engine control, the optimization of which is intended to release reserves, are usually stored as a data record on a memory chip. With a few manufacturers this is rewritable. This is generally a multi-dimensional map . With chip tuning, relevant data that are responsible for controlling and regulating the engine are linked in a modified way. When tuning with a multi-map technology, it looks like that four to eight maps are stored in the memory in an optimized way and are finally called up depending on the desired driving behavior. This ensures the best possible coordination of these parameters. Such data are e.g. B. The temperature of the engine and its surroundings, the air mass sucked in per unit of time and (if a turbocharger is available) the turbocharger's boost pressure .
Which processors are used for this plays a decisive role. The calculation cycle must correspond exactly to that of the main engine control unit in order to enable an exact grid of the maps in real time. In addition, the protective functions of the ECU (main control unit) are not manipulated in any way.
The output parameters are determined from the control parameters mentioned and possibly other permanently stored information, which are primarily the injection time, the injection quantity and, if applicable, the ignition time for each cylinder. Every combustion engine that has an electronic engine control can be modified by chip tuning, albeit mostly without additional power, but chip tuning is most effective with four - stroke diesel engines with a turbocharger. Some tuning specialists achieve short-term increases in performance of up to 44% of the series data.
With eco-tuning , on the other hand, the goal is to minimize consumption. This exploits the fact that most vehicle drivers do not take advantage of the savings potential of their vehicle. When driving at a constant rate, the injection quantity is reduced until there is a slight drop in speed that is not noticeable to the driver. At this point the minimum consumption for this driving situation is reached. This is a NO x -be trade-off . Here, the lower specific is fuel consumption (be) through a conscious accepting higher nitrogen oxide - emissions (NO x ) is reached, which can also be well beyond the permissible limits. A modification with an increase in emissions is not permitted according to StVZO Paragraph 3; the operating license is no longer valid.
The principle of eco-tuning is therefore a change to the control chip, whereby the engine is not trimmed for the highest possible performance, as in classic chip tuning, but for the lowest possible consumption. The software enables more power and torque in the lower speed range and thus ensures faster start-up.
Effect on the life expectancy of the motor
With a professional adjustment of the motor control, the durability and service life of the motor and drive roughly correspond to the series values, whereby it is assumed that the additional power is used to a small extent, because every higher load inevitably leads to higher wear and tear and significantly shorter life expectancy.
Modern turbodiesel engines in particular allow noticeable increases in performance. This is due, among other things, to the fact that the performance limits are not more gas-dynamic ( knocking ), as in the case of gasoline engines , but primarily mechanical . In other words, the performance of almost every turbo diesel engine can be increased significantly at the expense of the service life. Regardless of the type of fuel, long-term observations with regard to chip tuning have shown an increased occurrence of signs of wear on the turbocharger.
The programmed software of a reputable tuner changes the engine control maps only slightly so that no limit values are reached or even exceeded. Such tuning companies usually have a dynamometer with the help of which the tuning software can be adapted to the corresponding vehicle.
The warranty for the work done during the chip tuning can legally only cover the chip tuning itself, but not an engine or gearbox that was not sold by the tuner, but comes from the series manufacturer. The guarantees offered voluntarily vary from provider to provider and usually lead to a higher purchase price. Serious tuners usually include directly affected engine components in their warranties that are subject to a surcharge.
Implementation of chip tuning
- Individual coordination
- The tuning is fully adapted to the respective vehicle model and i. d. Usually the best result.
- As part of the individual coordination, for example, any manufacturing tolerances or modifications that have been installed subsequently can be fully taken into account. The tuning itself takes place within the framework of test bench runs or alternatively when driving on the road and is the most useful type of chip tuning.
- Use pre-optimized data sets
- The tuning is carried out using existing data sets that have already been optimized and created in the past on one or more vehicles of the corresponding vehicle model. However, different power reserves of the vehicle models cannot be specifically taken into account, for example, since the prefabricated data set is not adapted to the respective vehicle.
- Chiptuning by the user
- The required hardware is made available to the customer (e.g. loan or purchase) and enables independent optimization. Different performance levels are offered either free of charge or for purchase. The independent chip tuning takes place i. d. Usually completely at your own risk, as the customer can usually also use data sets which in some cases require previous modifications to the vehicle or which are above the standard load limit.
- Tuning boxes
- Tuning boxes are connected upstream of the OEM control unit and can be installed and removed in a few simple steps. Sensor values falsified by the tuning box lead to an increase in performance, but the unaffected control unit can only work within its factory-set parameters. With chip tuning on the control unit itself, more significant increases in performance can be achieved. The advantage is that the software on the control unit remains unchanged and there is no risk of damaging the control unit. With almost every service visit to the workshop, the software on the control unit is updated and the software tuning is lost. The disadvantage is that, due to the falsified sensor values, the motor does not switch to the emergency program or goes out in the event of danger. Serious tuners only change the values of the high pressure pump like with an additional chip.
Technical implementation options
A general distinction is made between 3 different methods of how the software can be read from the control unit and written to again. It usually depends on the generation of the control unit, which option is available. All 3 variants lead to the same result, since the installed software is mostly identical.
- Variant 1, soldering (replacing the chip in the engine control unit):
- The control unit is removed and the chip is unsoldered. Then the original software is read out with an EPROM programmer.
- While the software is optimized by a chip tuner, a socket can be soldered in instead of the chip. This has the advantage that the chip can be exchanged at any time with simple means
- without having to do any further soldering work. The tuned software is saved on a new chip - the original chip remains unchanged and can be reinserted into the socket at any time.
- This variant is usually the only way to carry out chip tuning on vehicles built before 2000 (hence the name 'chip tuning')
- Variant 2 OBD (read / write via the service interface):
- The engine control unit software can be read out and also written to via the vehicle's diagnostic interface using a corresponding tuning tool.
- This process requires neither mechanical nor soldering work, but is not possible with all vehicle models
- Variant 3 BDM / Tricore:
- The engine control unit must be removed for this procedure. A standardized interface is located inside the control unit, which enables reading or
- Describing the software allows. This interface is also used by the manufacturer during the initial programming (basic programming) of the control unit.
Differences between turbo and naturally aspirated engines
In contrast to turbo engines, naturally aspirated engines do not offer any significant potential to achieve a useful increase in performance - in relation to the output power - solely through chip tuning. In principle, this requires previous modifications to the engine and possibly components, which then achieve their full potential in the context of chip tuning or coordination.
Legal matters in Germany
As with many structural changes to a vehicle, chip tuning also requires an acceptance of the change by an officially recognized expert or inspector such as TÜV or DEKRA and a corresponding change in the registration certificate parts I and II, otherwise the vehicle's operating license will expire and it may no longer be moved in public traffic areas ( StVZO). Serious chip tuners therefore have parts certificates for their modifications and always hand them over with every order. In the case of less reputable providers, there are these reports, which are compulsory according to § 19 StVZO after the tuning, at most at high additional costs or not at all. Many dubious providers even advertise that their modification cannot be proven during inspections (and therefore a complex assessment is not necessary). However, vehicles with modified engine control software already stand out during an exhaust gas measurement, which is part of the general inspection. If there is then no entry according to StVZO, the operating license expires immediately. Driving without an operating permit is an administrative offense and is punished accordingly with a fine and points in Flensburg. Continuing the journey can be prohibited. The insurance cover can also expire due to impermissible and unapproved changes to the vehicle.
Therefore, before every design change, it should be checked whether an acceptance is required.
Even with serious chip tuning that has been properly approved and registered in accordance with the StVZO , the manufacturer's guarantee on the (new) vehicle expires with changes to the vehicle that are not authorized by the manufacturer. However, the manufacturer cannot reject the customer's warranty claim if parts are defective that have nothing to do with the tuning. A manufacturer can refuse to guarantee damage to the engine of a tuned car, but cannot repair a defective window regulator. Some (reputable) chip tuners take over the manufacturer's guarantee for affected components in new vehicles in order to also eliminate this disadvantage for the customer. If this is not the case, the customer can usually not assert claims against the manufacturer or the tuner in the event of damage to the engine or drive train, since the warranty for the work performed during chip tuning can only legally cover the chip tuning itself, but not an engine or a Transmission, which was not sold by the tuner, but comes from the series manufacturer.
- The engine manufacturers determine the standard key figures of the engines through lengthy and complex test series. It cannot be in the interest of the engine manufacturer to equip the engines with poor settings and thus to let them run below their real potential. Increasing the performance through chip tuning often leads to results that the engine manufacturer deliberately avoided, such as shorter service life, poorer emissions or high wear.
- A readjustment of the engine control or the control unit , for example to a different camshaft, exhaust system or higher boost pressure, is possible in principle, but is only possible with the help of an appropriate test device and a modern dynamometer.
- The under-consumption promised by chip tuning often fails to materialize; occasionally there is even increased consumption by changing the settings.
- Since the customer usually does not have a well-founded specialist knowledge, there is great potential for abuse by dubious tuners, as by manipulating the on-board computer, for example, better consumption values are suggested than actually available. Even modifying the electronic accelerator pedal subjectively gives more power.
- If there is no detection measurement, there is a risk of a placebo effect. The "felt" additional performance is usually significantly higher than the performance increase that was actually achieved.
- In turbodiesel engines, when the extra power is used, the particle emissions can increase enormously. This is then noticeable in the form of strong soot emissions when the vehicle accelerates.
- The higher exhaust gas temperatures, which arise as a result of the fuel component in the combustion mixture becoming lean, can damage the turbochargers, catalytic converters and soot particle filters.
- The higher exhaust gas temperatures lead to faster and irreversible thermal aging of the catalytic converter and the particle filter. This means that their ability to convert deteriorates, they become ineffective more quickly and remain so, even after the chip tuning has been removed.
- In turbo-diesel engines, the engine torque is often limited by the maximum permissible input torque of the transmission, which is why the series engines are throttled. An excessive increase in boost pressure through chip tuning means overloading and the risk of breakage for the transmission. An increase in performance can also damage the clutch and the rest of the drive train.
- Hans-Hermann Braess, Ulrich Seiffert: Vieweg manual automotive technology. 2nd edition, Friedrich Vieweg & Sohn Verlagsgesellschaft mbH, Braunschweig / Wiesbaden 2001, ISBN 3-528-13114-4 .
- Christian Tomanik: Car chip tuning. How to get more performance out of your vehicle 1st edition, Franzis Verlag, Poing 2004, ISBN 3-7723-4110-1 .
- Test report on chip tuning of diesel engines at Auto-Bild.de from March 13, 2002.
- On the chip tuning of gasoline engines at Auto-Bild.de from June 18, 2002.
- Chiptuning of tractors on the test bench, 2007 (PDF file; 224 kB) ( page no longer available )
- Klaus Mollenhauer: Handbook Diesel Engines . 2007, ISBN 3-540-72164-9 .
- - More power, less fuel? - Chip-Tuning and Eco-Tuning: guarantees of the Chip-Tuner. ADAC eV, accessed on February 24, 2015 . ( Page no longer available )
- Felix Rehwald: Eco-Tuning: Screwing on the Chip. Spiegel Online, November 9, 2005, accessed February 24, 2015 .