This article will be about how to use our CUMPAN Cockpit Assistant can be installed on any vehicle with an internal combustion engine and which measured variables can be recorded and displayed.
We have already documented a large number of different installation examples on our service page:
Service
From 2-stroke to 4-stroke, one- to four-cylinder, gasoline and diesel units, it’s all here.
Basically
The CUMPAN was developed for internal combustion engines. It combines the functions of speed display, temperature detection, shift light, gear, oil pressure and lambda display. The CUMPAN a powerful display instrument for engine monitoring.
Depending on the desired scope of services, corresponding Sensors and installation steps are required:
12V power supply
A stable 12V voltage is a prerequisite. The power supply for the CUMPAN should be on a switched (terminal 15) and fused line.
There are various connection options, e.g. prepared connections for auxiliary consumers, fuse taps or Branch connectors. In this document we have listed some examples where you can find a switched 12V line:
Manual
Speed display
The speed signal is supplied by the crankshaft position sensor. This sensor is present on every vehicle with electronic ignition. The signal is required for ignition timing and, if necessary, for fuel injection. The crankshaft position sensor is located on the alternator in the form of a pulse generator. As a rule, this is an inductive sensor with two cables (signal and ground). More rarely, a Hall sensor with three cables (signal, ground, power supply) is used. The signal cable can be determined either by a measurement, the circuit diagram or by trying it out at the speed input of the CUMPAN.
Signal acquisition at the crankshaft position sensor is significantly more accurate and less susceptible than inductive measurement at the ignition cable.
Helpful for finding the crankshaft sensor is this internet database, which keeps technical drawings of all common motorcycle models: https://en.microfiches.net/
Shift flash
The sound flash is a function that gives the driver visual feedback by flashing the display when a desired speed threshold is reached. This threshold can be used to warn of excessive RPM or to detect the optimum shift point for changing gears.
The CUMPAN additionally relates this function to the engine temperature and can thus be used for optimal warm-up of the engine. There is a possibility to set a threshold value for RPM depending on the motor temperature.
Example: The shift light warns at an engine temperature below 60°C already at 4,500 rpm. As soon as the engine temperature reaches 60°C, the shift light only warns at 7,500 rpm. All threshold values for temperature and RPM are freely adjustable. If this function is not desired, the RPM threshold can be set via the maximum speed of the engine and is thus deactivated.
Engine temperature
The engine temperature is one of the most important measured values to prevent possible damage to the engine or to detect it at an early stage. The oil or cooling water temperature display indicates whether lubrication or cooling is working properly and what RPM should be run. To record the oil or coolant temperature, simply find a thread/plug on the engine that is in contact with the appropriate fluid. On many engines there are blind plugs or unused threads that can be used for this case.
A list of the currently available temperature sensors can be found on the product page of the temperature sensor (Link?).
Oil or coolant temperature, which temperature should I record?
Water reacts faster to temperature changes than oil. The cooling water is often already at operating temperature even though the engine block has not yet warmed up. Overheating of the cooling water is usually not critical and leads to the radiator boiling over. Overheating of the engine oil can result in lubricant film breakage or cause thermal overload of seals.
It is optimal to have both temperatures in view, as this also allows oil or water shortage to be detected, for example. Since most engines already have a temperature sensor for the cooling water and a warning light for overheating installed as standard, it is often obvious to select the oil temperature. Of course, this question does not arise with air- or air-oil cooled engines.
Ambient temperature
The ambient temperature is recorded in any case. There is a temperature sensor in the wiring harness, about 40mm from the display housing. Depending on which display layout is selected, the ambient temperature may or may not be displayed. Temperature display can be switched between Celsius and Fahrenheit. When stationary, the temperature display can be affected by rising engine waste heat.
Analog inputs: Gear indicator, engine temperature, oil pressure, lambda, AFR
The CUMPAN has two so-called analog inputs (IN1 and IN2). Voltage signals between 0 – 5V are detected and interpreted. The available (2) inputs can be assigned to any of the following Sensors:
A gear sensor can be used to add a Gear indicator to the cockpit. Many Motorcycles (from EURO 4 at the latest) already have a gear sensor installed at the factory. The presence of a gear sensor is mandatory for the Gear indicator. The CUMPAN can interpret and display the output voltage values of the gear sensor. For this purpose, a teach-in function (calibration) is available in the CUMPAN, with the help of which a voltage value can be detected and then assigned to a corresponding gear.
At the analog inputs of the CUMPAN a second or third second or third motor temperature be connected. This allows the driver to monitor the coolant temperature, for example, in addition to the device’s native engine temperature detection. For this purpose, the CUMPAN Add-on Motor temperature 2 and a Temperature sensor necessary. As with native motor temperature detection, a suitable installation location must be selected. For monitoring the cooling water temperature, for example, the adapter for the Water temperature an.
Oil pressure is an important measured value for engine monitoring. It provides information about engine wear, the current viscosity depending on the engine temperature, possible oil dilution or even oil deficiency. Too low oil pressure results in engine damage because moving parts can no longer be sufficiently lubricated.
An Add-on is required to display the oil pressure in the CUMPAN.
Almost all modern internal combustion engines already have an oil pressure switch installed, which is a good indicator of the preferred installation location.
To avoid error messages, the original oil pressure switch should remain installed and the oil pressure sensor from the Add-on should also be installed. In this case, it is advisable to work with a connector to which both components can be installed at the same time.
The difference between an oil pressure switch and an oil pressure sensor is that the oil pressure switch only detects whether the pressure falls below a defined, fixed pressure threshold. In this case, visual feedback is usually provided by the familiar red warning light in the cockpit.
The oil pressure sensor we offer measures the actual oil pressure in a range between 0-10 bar and can output this value. This detection allows a precise assessment of the engine and even the oil.
In the CUMPAN it is possible to set a threshold value for the oil pressure, which when fallen below will show the oil pressure in red.
Poor engine running is often caused by an air/fuel mixture that is too rich or too lean. This may be caused by modifications to the air supply or exhaust system, or by defective ones. For healthy engine running or maximum performance, tuning of the air-fuel mixture is necessary. A narrow-band probe (jump probe) is installed at the factory on gasoline engines with a controlled exhaust catalytic converter. This is very well suited for mixture control to lambda = 1 (stoichiometric mixture) by the engine control unit. This probe is not suitable for further evaluation or influencing of the mixture outside Lambda = 1.
To be able to determine exact values, you need a wideband lambda sensor and a suitable lambda controller. The values output by the controller can be displayed with the CUMPAN, providing the driver with an accurate Lambda or AFR value. A calibration corresponding to the controller can be stored in CUMPAN.
