Post by Teh Man! on Mar 17, 2006 14:59:39 GMT -5
When tuning a vehicle, it is almost essential that you have some form of datalogging. That way, whether you are doing a WOT pull or tuning part throttle, you can easily review what needs to be modified in your maps. Some widebands come with a datalogging feature, such as the Techedge. However, Uberdata also has a datalogging feature that can communicate directly with the ECU. The only thing you have to come up with is an interface to connect your ECU to a laptop. The ECU uses TTL communication while a computer uses RS232. There are a couple of ways to convert from the ECU's "language" to the laptop's "language". You can either use your USB port or your serial port. Some laptops only have one of these ports, so you will want to base your decision on that first. In my case, my computer has one of each, however since my EPROM burner uses a USB port, I opted to use the serial port for datalogging so that I wouldn't have to constantly swap cables. Below is an outline of how to make your ECU "datalogging-ready". This writeup assumes you have decent soldering and electronics skills.
Serial Port
The piece of hardware that is required to use the serial port is the MAX223 and can be purchased here(http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html) for around $20. The way that I decided to use this was to cut a hole in the side of the ECU housing and mount it there. If you do any drilling/cutting of the ECU housing, always remove the main board so that you don't get metal shavings all over it.
Once it is mounted, you will need to connect four wires from the MAX223 to the ECU. These are transmit, receive, power, and ground. Start by desoldering the holes on the ECU circuit board. For tips on desoldering, refer to the ECU chipping section of this site. The holes are the part of the board that says "CN2". Use holes 1-4; #5 is not used:
Finally, connect the wires to the MAX223 unit as follows:
TX to pin 4 of CN2
RX to pin 2 of CN2
Ground to pin 1 of CN2
+5V to pin 3 of CN2
Here is the final result:
you can pick up a serial cable from RadioShack (part #26-117B):
USB Port
A cheap USB solution that has been discovered is a datacable meant for connecting a cell phone to a computer. It turns out that it has the correct circuitry that allows it to be used for datalogging purposes. The cable is available through RadioShack (part #17-787), however it is considered to be a discontinued item. I had no trouble finding a couple at my location, so chances are you could find them there as well. If you do find them there, they are marked down to $10. Otherwise you will have to resort to finding them on Ebay. It probably won't be under the same part number though.I also once heard from someone that they are available at Circuit City, although I have not verified this myself. Here is what the package looks like:
Drill a hole in the side of the ECU for the cable to go through. I used a strain relief to prevent damage in the case that the cable is pulled on. Also, it protects the cable from being worn by rubbing on the metal of the ECU case. A rubber grommet could be used as well. Next, cut off the phone plug end of the cable, and carefully remove about an inch of the outer insulation. Unbraid the shielding and twist it neatly. You can cut the plastic that is woven with the wires inside. Strip the brown wire and twist it with the shielding. Then connect this to pin 1 of CN2 on the ECU. The orange wire will go to pin 2, and the red wire goes to pin 4. Rather than connecting the wires from the cable directly to the ECU circuit board, it is wise to use intermediate wires of a medium gauge. This is because the wires inside the cable are small and fragile, not to mention the shielding is too big to fit through the circuit board hole. Be sure to tape it up well. To be safe, I insulated the remaining unused wires in the cable from eachother by cutting them at different lengths, then taping them to the cable. Finally, I tied the cable out of the way onto the support brace:
Using Datalogging
It is easiest to learn by doing in this case, but I'll give you a brief preview of what the datalogging in Uberdata can do. Start by plugging the ECU into your computer. Next, find out what COM port your serial or USB port is set to (this can be seen in Windows Device Manager). Otherwise if you don't know, just use trial and error until you see it working. Select the COM port in Uberdata under the datalogging tab. Then check which parameters you want to monitor. The graphs will begin plotting and you have the option of saving graphs for later reference. If you have a wideband and you'd like to interface it with Uberdata, you will need to feed the 0-5v output from your wideband to the O2 sensor input on your ECU. Since the ECU cannot interpret a 0-5v signal, you will have to burn a ROM that has closed loop disabled (misc tab in uberdata). When you disable closed loop, the ECU no longer varies fuel delivery based on what the O2 sensor reads - instead, it only reads from the fuel maps that you specify in Uberdata. If you're using a wideband with Uberdata datalogging, be sure to select the proper wideband in the datalogging tab, as different wideband manufacturers use different voltage-to-AFR tables. One cool feature of datalogging is the lambda log which is simply a table that corresponds with your fuel table(s). As you drive around, Uberdata will fill in the values that the O2 sensor reads whenever the ECU reads from a particular cell. This is a very nice way to tune. Here is an example:
You can use the following suggested air to fuel ratios when tuning for the best gas milage in part throttle and highest reliability in boost:
Finally, after you have monitored some data, you will find a file in uberdata called "datalog.csv" which is a comma-separated file of values that were logged. If you want to prevent this file from being overwritten, just rename it. It can be opened in Excel or notepad.
Serial Port
The piece of hardware that is required to use the serial port is the MAX223 and can be purchased here(http://www.compsys1.com/workbench/On_top_of_the_Bench/Max233_Adapter/max233_adapter.html) for around $20. The way that I decided to use this was to cut a hole in the side of the ECU housing and mount it there. If you do any drilling/cutting of the ECU housing, always remove the main board so that you don't get metal shavings all over it.
Once it is mounted, you will need to connect four wires from the MAX223 to the ECU. These are transmit, receive, power, and ground. Start by desoldering the holes on the ECU circuit board. For tips on desoldering, refer to the ECU chipping section of this site. The holes are the part of the board that says "CN2". Use holes 1-4; #5 is not used:
Finally, connect the wires to the MAX223 unit as follows:
TX to pin 4 of CN2
RX to pin 2 of CN2
Ground to pin 1 of CN2
+5V to pin 3 of CN2
Here is the final result:
you can pick up a serial cable from RadioShack (part #26-117B):
USB Port
A cheap USB solution that has been discovered is a datacable meant for connecting a cell phone to a computer. It turns out that it has the correct circuitry that allows it to be used for datalogging purposes. The cable is available through RadioShack (part #17-787), however it is considered to be a discontinued item. I had no trouble finding a couple at my location, so chances are you could find them there as well. If you do find them there, they are marked down to $10. Otherwise you will have to resort to finding them on Ebay. It probably won't be under the same part number though.I also once heard from someone that they are available at Circuit City, although I have not verified this myself. Here is what the package looks like:
Drill a hole in the side of the ECU for the cable to go through. I used a strain relief to prevent damage in the case that the cable is pulled on. Also, it protects the cable from being worn by rubbing on the metal of the ECU case. A rubber grommet could be used as well. Next, cut off the phone plug end of the cable, and carefully remove about an inch of the outer insulation. Unbraid the shielding and twist it neatly. You can cut the plastic that is woven with the wires inside. Strip the brown wire and twist it with the shielding. Then connect this to pin 1 of CN2 on the ECU. The orange wire will go to pin 2, and the red wire goes to pin 4. Rather than connecting the wires from the cable directly to the ECU circuit board, it is wise to use intermediate wires of a medium gauge. This is because the wires inside the cable are small and fragile, not to mention the shielding is too big to fit through the circuit board hole. Be sure to tape it up well. To be safe, I insulated the remaining unused wires in the cable from eachother by cutting them at different lengths, then taping them to the cable. Finally, I tied the cable out of the way onto the support brace:
Using Datalogging
It is easiest to learn by doing in this case, but I'll give you a brief preview of what the datalogging in Uberdata can do. Start by plugging the ECU into your computer. Next, find out what COM port your serial or USB port is set to (this can be seen in Windows Device Manager). Otherwise if you don't know, just use trial and error until you see it working. Select the COM port in Uberdata under the datalogging tab. Then check which parameters you want to monitor. The graphs will begin plotting and you have the option of saving graphs for later reference. If you have a wideband and you'd like to interface it with Uberdata, you will need to feed the 0-5v output from your wideband to the O2 sensor input on your ECU. Since the ECU cannot interpret a 0-5v signal, you will have to burn a ROM that has closed loop disabled (misc tab in uberdata). When you disable closed loop, the ECU no longer varies fuel delivery based on what the O2 sensor reads - instead, it only reads from the fuel maps that you specify in Uberdata. If you're using a wideband with Uberdata datalogging, be sure to select the proper wideband in the datalogging tab, as different wideband manufacturers use different voltage-to-AFR tables. One cool feature of datalogging is the lambda log which is simply a table that corresponds with your fuel table(s). As you drive around, Uberdata will fill in the values that the O2 sensor reads whenever the ECU reads from a particular cell. This is a very nice way to tune. Here is an example:
You can use the following suggested air to fuel ratios when tuning for the best gas milage in part throttle and highest reliability in boost:
Finally, after you have monitored some data, you will find a file in uberdata called "datalog.csv" which is a comma-separated file of values that were logged. If you want to prevent this file from being overwritten, just rename it. It can be opened in Excel or notepad.