Engine Testing and Maintenance Data Logger Selection Report Data Logger Wiring Data Logger Sensor Calibration Data Logger Results Intake Design Exhaust Design Resources and Technical Contacts
Upon purchasing the Race Technology DL-1 Data Acquisition system, the team was required to locate all sensors that were going to be used, and the corresponding wires found and marked.  From the stock Aprillia RXV 550 wiring diagram found here, it was easy to establish which wires were going to be spliced into and fed into the data logging unit.  For this year's car, RPM, exhaust gas temperatures (EGT), air fuel ratios (UEGO), water temperatures, intake air temperatures (IAT), throttle position (TPS), gear position, and global positioning (GPS) will be actively monitored using the DL-1 unit.  Depending on the input channel, the DL-1 is capable of reading voltage signals from 0 to 5V, and 0 to 15V.   For the engine parameters (RPM, EGT, UEGO, water temperature, intake air temperature, throttle position, and gear position) being monitored above, only the 0 to 5V channels will be needed, as none of them have output voltages which exceed 5V.  The pin layout of the DL-1 unit can be seen here.

In the case of both EGT sensors, and the single UEGO sensor, the car was already fitted with an AEM X-WiFi box which features output wires specifically for feeding into a data logging unit.  The X-WiFi takes in the EGT and UEGO signals, and is able to process them and send them wirelessly to a computer, or cellular phone with internet capabilities, as well as send the voltage signals to the output wires which the team are using for logging purposes.  These three sensors each have voltage output ranges from 0 to 5V depending on the temperature or air fuel ratio they are reading.  The wiring diagram to the right shows that the blue, grey, and white wires from the output side of the X-WiFi carrying EGT, and UEGO sensor voltages are fed into analog inputs 1, 2, and 3, of the DL-1 unit respectively.  Once the voltages are logged onto the SD card, they are modified using the supplied Race Technology "Annalysis" program and converted from voltages to useful units such as temperature and AFR.

A convenient aspect of the Aprilia's ECU (Walbro ECU-C), is the built in RPM signal coming from the ECU and feeding into the stock dash display unit.  This coupled with the DL-1's built in low reference RPM input made it easy to connect to, and log RPM data.  The logging unit is able to read the pulse signal from the ECU, and convert it to units of RPM in order for them to be logged to the SD card and later analyzed against other parameters using the Race Technology software.  

The water temperature, intake air temperature, throttle position, and gear position inputs to the DL-1 can be seen to the right as yellow, blue, red, and red respectively.  The yellow water temperature signal, which is wired into analog input 4 of the DL-1 unit, is sent from a universal sending unit mounted in one of the engine's main coolant lines.  Over the course of  the next semester the engines stock temperature sensor will replace the aftermarket in-line unit for simplification and accuracy purposes. The blue IAT signal wired into analog input 7 of the DL-1 unit is sent from the Aprilia's stock sensor and is currently being analyzed as simply a voltage since calibration of the sensor has not yet been performed, and no conversion factors from voltage to temperature are known.  Finally, the two red wires, TPS and gear position signals which are wired into analog inputs 6 and 5 of the DL-1 unit are also sent from factory sensors.  Like the IAT signal, the TPS signal is being logged and analyzed as a voltage, since only the magnitude of it is of importance, and no conversion factors are needed to accurately understand it.  The gear position signal is currently being logged into the DL-1 unit, but when the DASH2 display unit is installed next semester, it will be sent to one of its analog inputs in order to display the current gear based on the output voltage from the sensor.  Factory specifications for the IAT, TPS, and gear position sensors can be seen here.  

One major benefit of the DL-1 unit is its built in GPS unit and antenna.  The unit's capabilities of logging GPS, and therefore speed data is crucial in reviewing data from testing situations similar to those which will be required during competition.  The ability to analyze lap times and things of that sort using the GPS data will be extremely beneficial during testing next spring.  This data will give us an idea of approximately where we stand in regards to other teams during various competition events.  

--The above links were taken from the Aprilia Shop Manual, and DL-1 User's Manual--