Within this page you will find information and definitions of strategies and theory's which pertain to MoTeC Engine Management Systems. Topics discussed are listed below. Click on the ones you would like to learn more about.
Sequential Fuel Injection - Sequential means that each injector for each cylinder is triggered only one time during the engine's cycle. Typically the injector is triggered only during the intake stroke. True sequential injection requires the ECU to know not only where top dead center is, but also which half of the cycle the engine is on. TDC on a 4 stroke occurs 2 times during the cycle, once on compression and once on exhaust. MoTeC references all timing events that occur within the ECU, to Top Dead Center Compression. This generally requires an input on the engine's camshaft to provide the ECU with a SYNC signal. Once the ECU is synched, injection timing can be optimized to provide the most efficient mixing of fuel and air into the cylinder. Control of injection timing can lead to increases in midrange torque while decreasing emissions and fuel consumption.
Semi-Sequential Fuel Injection - Semi-Sequential means that 2 or more cylinder's injectors are triggered at the same time, but only 1 time during the engine's cycle. This requires the ECU to be synched with the engine's cycle. Typically injection timing is retarded from the optimum timing point for full sequential by an angle which is equal to 1/2 the angle between 2 cylinders in crankshaft degrees. On a V8 Chevrolet, the injectors for cylinders 1 and 8 would be triggered at the same time. They would be triggered 45 degrees late for cylinder number 1 and 45 degrees early for cylinder number 8. Degrees between 1 and 8 = 90 ; 1/2 of 90 = 45. Semi-sequential allows optimization of injection timing which typically leads to increases in midrange torque and a reduction in fuel consumption for equivalent power compared which Batch fire.
Injection Timing - With a synced engine which uses 1 injector in each intake manifold runner, it is possible to phase the firing of the injector so that it only sprays during the intake stroke. This allows you to introduce fuel into the intake stream precisely at the time when the airflow into the cylinder is the greatest providing the best possible atomization and the highest efficiency. MoTeC offers a user definable 2 or 3 dimensional Injection Timing adjustment table so that you can accurately match any engine's injection timing demands. Tuners can select either beginning or end of injection on which to base the timing table. This allows the tuner the ultimate in adjustability to suit any engine combination. With the M4 and M48 ECU's Injection timing is adjustable in 5 degree increments while the M400/600/800 Series offer .1 degree resolution making them suitable for Gasoline or Diesel Direct Injection.
Batch Fire - Batch fire means that 2 or more injectors are triggered at the same time once every crankshaft revolution. If the ECU is synched with the engine's cycle, the injection timing can only be half optimized as fuel is injected both on the intake stroke and on the power stroke. Companion cylinders are paired in batch fire mode similar to wasted spark ignition modes. The advantage of batch firing is that the ECU needs only to know where TDC is. This means that a sync on the cam is not required. The disadvantage to batch firing is that the Injector Dead Time is doubled for the engine's cycle. This leads to a decrease in fuel flow and typically requires a larger, less efficient injector to be used to make up for the loss of flow. On High Horsepower applications this means the idle quality will suffer tremendously.
Injector Dead Time - Injector dead time refers to the latency of the injector in producing maximum flow rate. All injectors require a certain amount of time to open completely and produce maximum flow. The amount of time is dependant on several variables including; fuel pressure, battery voltage and physical characteristics of the injectors themselves. Typically higher fuel pressure or lower battery voltage tends to increase the dead time. This leads to a reduction in fuel flow in to the engine and as a result influences the engine's state of tune. Luckily MoTeC allows the user to define an injector Dead Time table if the values are known, or use a standard compensation which is known for a number of injectors. The ECU automatically adjusts the values as the battery voltage changes to ensure that the fuel curve remains constant. If a fuel pressure input is used on the system, MoTeC can compensate for variations in fuel pressure to achieve a consistent fueling even with varying fuel pressures.
Bank to Bank - Multipoint - Bank to Bank - Multipoint is the least efficient electronic method of injecting fuel into an engine. Each injector is physically located in a position which allows its fuel output to be delivered to a single cylinder, but the fuel is injected once per rev and injection timing is of no real value even if the ECU is synched to the engine's cycle because an entire bank of cylinder's injectors are fired at the same time. The advantage of Bank to Bank is that the ECU typically does not need to be synched at all. This makes it a simple retrofit to engines which never used crank or cam triggers, because it can run the engine with simply 1 pulse per cylinder firing. Ignition timing can still be adjusted, but it is required that the engine use a mechanical distributor to distribute spark from 1 coil. No individual cylinder trimming is possible.
Individual Cylinder Trim - When an ECU is synched to the engine's cycle, it becomes possible to individually adjust a cylinder's ignition advance and also if the engine is full sequential, the amount of fuel which is supplied to that cylinder. MoTeC allows individual overall trims of each cylinder's ignition and fuel quantity in all models. In the M4 and the M400/600/800, Individual cylinder trim tables are provided which allow the tuner to vary the timing and the fueling based on RPM and Load. Typically fully variable ignition advance requires the use of multiple coils to avoid rotor-tip to cap-terminal alignment problems which may lead to spark scatter. Additionally if a single inductive type coil is used, it is possible if high fluctuations in advance occur between cylinders, that the coil does not have sufficient time to charge which leads to reduced coil output energy and possible misfire.
Bank to Bank - Singlepoint - Singlepoint involves placing the injectors in a single common injection point in the inlet path. This is typically done on roots or screw supercharged engines and some normally aspirated engines. This provides the least efficient method of using Electronic Fuel Injection. About the only method which provides less control is Carburetion. From a power standpoint, single point is not tremendously worse. Fuel consumption is typically significantly increased over any of the above methods. There is virtually no control possible as far as each cylinder is concerned and the inherent problems of delivering 2 substances with differing mass through the same passages an into the combustion chamber are present. The advantage of Singlepoint is that it does not require the ecu to be synched in any way. MoTeC makes an attempt to smooth out the fuel delivery of singlepoint by triggering the injector drives in a staggered manner. This provides a smoother more consistent delivery of fuel and reduces the instantaneous drain on the battery/charging system which can lead to ignition misfire in other systems.
Narrow Band Lambda - Narrow Band Lambda provides an output voltage between .1v and 1.0v dc based on the oxygen differential between the exhaust pipe and the atmosphere. This can give an indication of the air fuel ratio at which the engine is running however the sensor range is limited to ratios of about 14.0:1 (1.0v) and 15.4:1(.1v). At ratios beyond this range, the sensor output does not increase or decrease making it virtually useless for tuning an engine for anything other than steady state cruising. The advantage of Narrow Band Lambda comes into play while trying to keep emissions in check. The sensor provides a signal to the ECU which basically indicates either rich (output voltage above .5v air fuel less than 14.7) or lean (output voltage below .5v air fuel greater than 14.7) but really does not describe to what degree the mixture is either rich or lean. This is fits perfectly in with the need for "perturbation" of today's 3 way catalysts which need excess air to catalyze Hydrocarbon and Carbon Monoxide, and excess fuel with which to reduce Oxides of Nitrogen. Because of this requirement by the catalyst, Narrow Band Lambda Control is constantly varying the air/fuel ratio both slightly above and below 14.7:1 in such a manner that the average air fuel ratio is maintained at 14.7:1. Most engines in use today, produce peak power with air fuel ratios in the 12:1 - 13.5:1 range well below the measuring capability of a narrow band lambda sensor. It is for this reason that Narrow Band Lambda is of no help for high loads and or RPM's.
Wide Band Lambda - Wide Band Lambda provides the ECU with a specific definition of the air fuel ratio at which the engine is currently running. Wide Band Sensors are able to depict air fuel ratio's as rich as 10.5:1 and as lean as 18:1 and report the exact lambda to the ECU. This is done a number of ways. MoTeC M4 and M48 ECU's use Bosch 4 wire Wide Band Lambda sensors to measure wide band lambda. MoTeC M400/600/800/880 ECU's use either the Bosch LSU or the NTK UEGO 5 Wire Wide Band Lambda Sensor. MoTeC then uses this information to determine the actual lambda and displays this on the console and or uses it for Lambda Control if the ECU is set up to do so.
4 Wire Wide Band Lambda Sensor - This technology takes advantage of the fact that a 4 Wire Wide Band Lambda sensor's voltage output is based on not only the oxygen differential between the exhaust pipe and atmosphere, but also is dependant on the temperature of the sensor itself. Sensor impedance varies with temperature, so a MoTeC ECU measures not only Wide Band Lambda Voltage, but also the sensor impedance. It is not possible to properly display lambdas without monitoring the sensor temperature. Systems which do not use at least a 4 wire sensor typically have errors in displayed lambda as high as 8%!
5 Wire Wide Band Lambda Sensor - This newer technology is used to determine the air fuel ratio of an engine by measuring lambda sensor output and measuring the current required to hold the sensor voltage output constant. An oxygen sensor produces voltage and a small amount of current as oxygen atoms pass across its substrate from high concentration to low concentration. The greater the flow of oxygen, the greater the voltage produced. This is the case when a rich mixture is encountered. Conversely, when current is applied to an oxygen sensor, oxygen atoms are moved from a low concentration to a high concentration or vice versa depending on the polarity of the current applied. The MoTeC M400/600/800/880 ECU's are capable of measuring this type of sensor input which offers increased speed and accuracy over the older technology 4 wire sensors. M4 and M48 ECU's can leverage the 5 wire technology by connecting a MoTeC PLM, which has a definable analog voltage output, to the Lambda input on the ECU.
Bosch LSU and NTK UEGO Sensors - Both the MoTeC M400/600/800/880 and the MoTeC PLM are capable of operating with either the NTK UEGO or the Bosch LSU-4 5 wire wide band sensors. Of the two, the NTK is most accurate. It is a true laboratory grade sensor. Its accuracy has been found to be about 1.5% better than that of the Bosch LSU. Additionally the NTK has a better response time than does the LSU again about 1.5%. The NTK is the benchmark against which the LSU is measured. The advantage of the LSU sensor is its lower price compared to the NTK. If you are doing very precise and accurate laboratory type testing, the NTK is the sensor for you. Both sensors have a life expectancy of 500 hours on unleaded fuels and that number is diminished to 50 hours using leaded fuels. Lambda Sensors are very similar to spark plugs with respect to their estimated life expectancy. Spark Plugs are designed to last 40,000 miles under optimum circumstances but they can be damaged in less than 1 mile by misuse. A lambda sensor can be thought of the same way. Misuse by overly rich mixtures, high temperatures, overtightening or dropping can have a very negative effect on lambda sensor life. Like spark plugs, lambda sensors cannot be returned under warranty.
What is Lambda? - Lambda describes an equivalence value in percentage of the chemically correct air-to-fuel ratio for any type of fuel. If the air fuel ratio measured in the exhaust pipe of an engine is at the chemically correct (stoichiometric) ratio of air-to-fuel, lambda is equal to 1.0. In the case of gasoline, lambda 1.0 is equivalent to 14.7:1 air-to-fuel. Lambdas less than 1.0 indicate the engine is running richer than stoichiometric, while lambdas greater than 1.0 indicate a lean mixture. If we measure a lambda value of 1.06 and we want a lambda value of .95, we simply increase the fuel delivered to the engine (pulsewidth) by 11 percent. This will place us exactly at .95 lambda. By using the Lambda Was or the Quick Lambda functions a tuner can quickly shape the fuel table to match the engine's exact requirements. In addition, the W Lambda function copies the Quick Lambda value to the sites immediately to the right and up above to help keep the fuel table variance from one site to another at a minimum.
Quick Lambda and Lambda Was - A MoTeC ECU, allows the user to define a lambda goal table based on load and rpm. The Quick Lambda function in the software allows a tuner to quickly adjust the values in the fuel control table to achieve the goal lambda, based on the lambda reported by the sensor. If the reported lambda is .98 and the goal is .93, the ECU automatically jumps to the current load site, and multiplies the value in the site by 1.05. The next time the engine runs in that site, the lambda will be .93. Similarly, Lambda Was allows a user to locate a load and rpm site in the main fuel table and enter a recorded lambda measurement from a data log. The ECU multiplies the load site value by the difference between entered lambda and the goal lambda value so that the engine will achieve the goal lambda the next time it runs on that load site. This makes tuning much faster and easier than calculating the required enrichment based on an air fuel ratio number. Of course you can manually do multiplication, division, addition and or subtraction on any site or a number of sites with only a few keystrokes, and the overall trim function allows you to trim the entire fuel or ignition table up or down based on percentage.
Lambda Control - There are two types of control methods used in closed loop fueling. Narrow band closed loop control attempts to keep the air fuel ratio "pertubating" (dithering) slightly richer and slightly leaner than stoichiometric for emissions control. In a MoTeC ECU, narrow band control is simply turned on or off based on load and rpm. Wide Band closed loop control measures the current lambda and adjusts the fuel delivered to the engine, by comparing the measured lambda to the preset lambda goal table.
Configurability - MoTeC ECU's are well known for their ability to be customized to meet the demands of nearly any application. Software configurable hardware within the ECU allows a tuner to match the requirements of any inductive or capacitive discharge type ignition available. Triggering can be done using hall effect, magnetic pickup, logic level switch or optical sensor. There are specific modes which are selectable to allow MoTeC to read LS-1, LT-1 Opti-Spark, Ford TFI, Subaru, Honda, Mazda, BMW, Nissan, Toyota, as well as aftermarket flying magnet or hall type crank triggers. If you make a change to a new type of trigger wheel, MoTeC allows you to simply redefine the signals in software. No need to send your ECU in for hardware upgrade. Every MoTeC ECU can be configured quickly so it is possible to borrow an ECU, send your calibration file to the new ECU and be up and running in merely seconds.
Data Logging - MoTeC M4 and M48 ECU's feature 512Kbyte non-volatile logging memory space. M800's feature a full Megabyte of logging space and the M880 is available with up to 4 Megabytes of logging memory. Tuners can select which items they want to log, and what rate they wish to sample. M4 and M48 can sample up to 20 times per second (.050 Seconds) while M800/880 max out at 200 times per second (.005 Seconds) Maximum logging time is dependant on the number of items being logged and the rate at which you are logging.M4 and M48 maximum logging time is 382 minutes at 1 sample per second. If the logging memory becomes full, MoTeC automatically begins logging over the top of the existing log ensuring that you will always have the most recent data available in your log when it is retrieved.
RPM Limiting - RPM Limiting can be done a number of ways using MoTeC. Software allows you to select whether your cut will be based on fuel only, ignition only, fuel with ignition 100 rpm above, ignition with fuel 100 rpm above or both fuel and ignition at the same time. An adjustable control range allows the tuner to set the harshness of the cut and an adjustable randomizer gives the tuner the opportunity to get a fully random cut no matter what number of cylinders the engine has. The overall RPM Limit sets the maximum engine rpm you want the engine to ever see. Other cuts allow starting line rev limits which typically are lower than the maximum rpm limit. Using a 9 position trim switch, MoTeC can provide you with 9 separate, driver selectable RPM Limits for ultimate adjustability to conditions without the need for a laptop to change the setting.
Oddfire tables - Tables in the ECU describe the oddfire angle in crank degrees for use on oddfire engines such as the Viper V-10, Harley Davidson V-Twin and the Chevy V-6. Simply tell the ECU the number of degrees past TDC Number 1 that each cylinder arrives at its own TDC. A special requirement for triggering is needed to run the oddfire engines. The crank input must have at least 1 tooth per TDC and they must be evenly spaced. This usually requires a 12 tooth wheel in the case of the V-6 Chevy. MoTeC CDI-8 Capacitive discharge Ignition can be used to supply the spark to oddfire engines of 8 cylinders or less controlled directly by a MoTeC ECU. For engines with greater than 8 cylinders, 2 CDI-8's can be used.
Comprehensive Online Help - All MoTeC software comes with Comprehensive online help available by pressing the F1 key on your keyboard. Whether it is Engine Management, Data Acquisition or our Data analysis software you can always access the help files through the use of the F1 key.
CDI-8 Ignition - Capacitive Discharge Ignition has been used in racing and in some automobiles for a number of years. MoTeC offers one of the industry's most advanced capacitive discharge ignition systems available. The CDI-8 is an 8 channel CD Ignition which can either run in stand alone mode (meaning it does not require an ECU to run it) or in slave mode. In slave mode, the CDI-8 receives an encoded signal from a MoTeC ECU which tells it which coil output to fire. In this mode, a CDI-8 can deliver a full energy spark at up to 1.1KHz which is enough to keep up with an 8 cylinder engine turning 16,000 rpm!
MoTeC Software - Always free from www.motec.com New software upgrades will allow additional features for your ECU. Since each ECU is produced with all of the same hardware, there will never be an issue of a feature not working with an older ECU. New features will always work with every ECU.
Security - MoTeC offers its customers the option of securing their tuning file through two methods. The first is a simple password protection which can be set on the ECU so that others are not able to make changes to the tuning file nor can they send a new file to the ECU unless they have the password. The password can be reset as often as you like, and you may choose to turn the password off at anytime but you must know the password in order to perform these functions. Additionally, MoTeC allows the tuner to encrypt a file which is stored within the ECU. In this case, the file can only be sent to an ECU which has a matching password for the encrytped file. If file encryption is used, a tuner could send an encrypted file to a customer with a matching password, and the customer would be able to send the file to the ECU without knowing the password. The customer would still not be able to view or in anyway modify the file. Data downloads can always be retrieved whether or not a password is set on an ECU.
High/Low Injection Capability - On many types of racing engines, tuners may find improved efficiency by changing the physical location of the injector in relation to the intake valve. MoTeC allows the user to run 2 sets of injectors in the inlet path and switch from one to the other with a 3 dimensional table based on load and rpm. Typically this feature is used when an engine is making substantial amounts of horsepower but requires only small amounts of fuel at low speeds. In this case, the tuner can select 2 injectors of differing flow rates, one for low speed operation, the other for high speed/power operation. MoTeC allows you to define the flow differential between the 2 injectors, so that the proper amount of fuel can be delivered out of each injector. Another way to use the MoTeC High/Low capability, is to use 2 injectors of equal flow rate, but located at different points in the inlet path. In this manner, fuel injection location can be varied at certain points in the rpm band to provide the highest efficiency. Of course MoTeC allows you to enrich or enlean the engine at the transition from 1 set of injectors to the other to provide seamless operation.
Crank Index Position - The CRank index Position is perhaps the most important timing value in the ECU. The CRiP tells the ECU where the engine is in relation to TDC Cylinder #1. The CRiP is defined as the distance in crankshaft degrees, between the reference tooth when it is aligned with the crankshaft position sensor, and Top Dead Center Compression Number 1. For example, if the reference tooth is aligned with the crankshaft sensor when the crankshaft is 55 degrees before TDC Compression Number 1, then the CRiP is 55. An easy way to determine the CRiP before startup is to rotate the crankshaft in the direction of rotation until the reference tooth is aligned with the crankshaft position sensor. Then measure the number of degrees, required to turn the crankshaft in the direction of rotation until the number 1 cylinder is at Top Dead Center of the Compression stroke. Once you determine this value, you may start the engine and enter the CRiP set screen under the Ignition menu. Use a non dial-back timing light to check the CRiP. The timing advance displayed in the CRiP set screen should match the measured value using the timing light. If they do not match, move the CRiP value until the timing does match.
Reference Tooth - The definition of the Reference Tooth depends on the type of Ref/Sync mode being used. If using missing or extra tooth type modes, the reference tooth is defined as the tooth which occurs directly following the missing or extra tooth or teeth. If using 1 tooth per TDC or Multiple tooth mode with a sync input, the reference tooth is defined as the tooth which occurs directly following the sync input.
Rotary Ignition Split - Factory Rotary engines use 2 spark plugs per rotor. Both spark plugs in a common rotor are not fired at the same time. There is a delay between the time when the leading spark plug is fired, and when the trailing spark plug is fired. MoTeC wrote special software to be able to mimic this type of ignition control for rotaries in the M4 and M800/880. A table is available to define differing amounts of timing split to suit any application and driving condition. Of course if you do not wish to use the split timing function MoTeC can accomodate that as well.
Auxiliary Tables - MoTeC Engine Management systems are extremely adaptable to differing engine requirements. One way MoTeC makes this possible is through the use of Tuner definable output controls. A 3 dimensional table can be selected by the tuner with several inputs available to use as the table axes. Typically Engine RPM, Engine Temperature, Air Temperature, Manifold Pressure, Throttle Position and Auxiliary Inputs are available to set up the table. Tuners typically use this type of control for engines which have switchable cam profiles such as the Honda V-Tec. The 3D table can be set so to Throttle Position versus RPM for example and the tuner can turn on the V-Tec based not only on RPM but also load so the cam timing can be optimized for varying loads.
Fully Variable Camshaft Timing - MoTeC is proud to be the industry leader in the aftermarket for controlling engines with fully variable camshafts. We have several special modes written to allow full control of up to 4 fully variable camshafts per engine such as the Dual Vanos BMW V8 using our M800/880 series of Engine Management Systems. Special Ref/Sync modes were written to allow the tuner to use the stock trigger wheels and sensors. Camshaft timing can be independently adjusted for each cam in 1/2 degree increments based on RPM and Load. With full adjustment of camshaft opening and closing points, the engine's volumetric efficiency curve can be stretched providing optimum cylinder filling over a much wider range of RPM, increasing the average horsepower and ultimately making the car faster.
Drive by Wire control - MoTeC is the first in the industry to adopt drive by wire throttle control using OE components. Many of the newer models of cars are equipped with electronic throttle control. MoTeC retains all of the standard redundant sensors that the factory uses for safety. In addition to very precise control of the throttle position, throttle by wire also incorporates idle speed control and traction control. MoTeC Drive By Wire is available for certain Bosch, Delphi and Nissan systems using our M800/880 series of Engine Management Systems and we are working on additional Drive By Wire systems on a daily basis. If you are interested, please call to discuss your system's requirements.
Telemetry - All MoTeC products offer the ability to transmit data from the ECU using a 3rd party radio, to a PC using another radio, for real time monitoring of engine functions. The Telemetry option allows the ECU to transmit this data over the radio's and MoTeC's Telemetry Monitor software allows the tuner to view the data remotely. Note that Telemetry is for real time analysis only. No data storage is done on the PC, however the ECU will still be able to log the data.
Remote Logging - When used in conjunction with the MoTeC Telemetry option, remote logging allows the data which is monitored with Telemetry Monitor, to be stored on the PC and converted to a data format which is readable using MoTeC Interpreter, our data analysis software. Note that the Telemetry option must be enabled in order for Remote Logging to function.
Cold Junction Compensation - When a Thermocouple is connected to a measuring device, the variance in resistance of the connectors between the thermocouple and the device, create a voltage drop. The drop in voltage means that the signal input from the thermocouple will be incorrectly reported. Additionally, the temperature at the connection point affects the sensor signal. It is therefore extremely important that the temperature at the connection point be measured and accounted for for the Thermocouple to report an accurate signal. MoTeC Expansion Modules accomplish this by measuring the temperature at the connection point so the signal can be adjusted and more accurately reported.
Controller Area Network (CAN) - A communication network for several devices similar to a LAN (Local Area Network) used in Personal Computers. The CAN bus allows many devices to be connected via 2 wires and share information with each other as needed. MoTeC uses CAN to communicate with the ADL2 and M400/600/800/880 ECU's from the laptop. In addition, these devices as well as the BR2, PLM, E888/E816 and other CAN enabled units can be connected onto the bus to provide additional input and output capability without the need to use physical connections on the devices.