How can I do datalogging of Ignition timing on an 87 Turbo?
#16
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The MoMonitor is still listed on the Vitesse website, but I received this reply form John:
"Unless you use the tools we developed (Motronic Monitor or Editor) there is no way to log timing on the 944/951. The bad news is that we do not sell the tools.
The good news is that the MAF will be on sale during the 3rd or 4th week of January."
I like the good new part and will probably buy the MAF setup when he gets back.
"Unless you use the tools we developed (Motronic Monitor or Editor) there is no way to log timing on the 944/951. The bad news is that we do not sell the tools.
The good news is that the MAF will be on sale during the 3rd or 4th week of January."
I like the good new part and will probably buy the MAF setup when he gets back.
#17
Originally Posted by johntorg
The datalogger looks like a very useful tool, even if it can't directly do timing. It can monitor digital and analog signals. It can also be used as a scope, which is usefull for checking sensor signals. I think with some programming and reading the refernce signal from the flywheel and the coil trigger signal, it should be able to measure and log timing.
Anyone have any thoughts on this approach?
Anyone have any thoughts on this approach?
I really don't see the point in knowing the exact timing values? They are just numbers that alone will tell you nothing. You cannot compare them to other engines, especially modern 4-valve ones that has much faster burn rate.
What's interesting is the timing advance were you have highest power without knocking. To find that advance you have to test different timing values until you find the best ones and regardless if you use a piggyback in which case you'll see the values as corrections added to the DME ignition curve, or if you change the chip, in which case you see the map table values. What I'm trying to say here is that in neither case you have any advantage in knowing that the timing is for instance 33° BTDC since that will tell you nothing.
I know how the DME calculates ignition timing but I have not bothered to calculate what the maps correspond in degrees since it is of little interest for me. It's just as easy to work with the map values.
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Tomas, do the know at what voltage the knock sensors in the 944 indicate knocking? I guess I may be a little nervous, since my 1.8T Big turbo chip is way to far advanced and causing the ECU to pull 9 degrees of timing to keep the engine from melting. While you have the knowledge of the DME calculations, and apparently the ability to modify the advance, I do not.
Just trying to get comfortable with the technology available in the 944. Actually if John's chips work as well as everone says, this may be a total non-issue.
Just trying to get comfortable with the technology available in the 944. Actually if John's chips work as well as everone says, this may be a total non-issue.
#19
Three Wheelin'
"Tomas, do the know at what voltage the knock sensors in the 944 indicate knocking?"
Many voltages, it is an analog output sensor, see the link in my signiature, click knock sensor on the panel. You can also learn some things about the 951 engine management at the same site.
Vitesse's chips will probably be fine without you personally understanding anything, if you give him your exact setup and have him burn some with your desired ignition map.
Many voltages, it is an analog output sensor, see the link in my signiature, click knock sensor on the panel. You can also learn some things about the 951 engine management at the same site.
Vitesse's chips will probably be fine without you personally understanding anything, if you give him your exact setup and have him burn some with your desired ignition map.
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Originally Posted by Tomas L
I don't think it will be that usefull to try to log timing with that datalogger (although it seems like a usefull product) since the sampling frequency is to low, you will not get enough resolution and therefore the accuracy will be very bad. You need some type of counter to do this.
I really don't see the point in knowing the exact timing values? They are just numbers that alone will tell you nothing. You cannot compare them to other engines, especially modern 4-valve ones that has much faster burn rate.
What's interesting is the timing advance were you have highest power without knocking. To find that advance you have to test different timing values until you find the best ones and regardless if you use a piggyback in which case you'll see the values as corrections added to the DME ignition curve, or if you change the chip, in which case you see the map table values. What I'm trying to say here is that in neither case you have any advantage in knowing that the timing is for instance 33° BTDC since that will tell you nothing.
I know how the DME calculates ignition timing but I have not bothered to calculate what the maps correspond in degrees since it is of little interest for me. It's just as easy to work with the map values.
I really don't see the point in knowing the exact timing values? They are just numbers that alone will tell you nothing. You cannot compare them to other engines, especially modern 4-valve ones that has much faster burn rate.
What's interesting is the timing advance were you have highest power without knocking. To find that advance you have to test different timing values until you find the best ones and regardless if you use a piggyback in which case you'll see the values as corrections added to the DME ignition curve, or if you change the chip, in which case you see the map table values. What I'm trying to say here is that in neither case you have any advantage in knowing that the timing is for instance 33° BTDC since that will tell you nothing.
I know how the DME calculates ignition timing but I have not bothered to calculate what the maps correspond in degrees since it is of little interest for me. It's just as easy to work with the map values.
#21
Hi,
Because you have already an LM-1, you'll be in luck if you also have or get an LMA-3. The new beta4 firmware for the LMA-3, available on the innovate forum, allows datalogging of ign. timing along with all the other stuff it can log.
Regards,
Klaus
Because you have already an LM-1, you'll be in luck if you also have or get an LMA-3. The new beta4 firmware for the LMA-3, available on the innovate forum, allows datalogging of ign. timing along with all the other stuff it can log.
Regards,
Klaus
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I read the manual for the LM-3. If it can handle the number of teeth on the flywheel of the 944 it should work. It would certainly work if I installed a 60 minus 2 wheel as in a standalone setup. I read somewhere the way that the the 944 calculates TDC. Can anyone point me to that writeup? Once i know that and the number of teeth, I'll post a question on the innovate website
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I found this in http://users.wpi.edu/~mark944/motronic/ "132 teeth on the flywheel, ref sensor detects a stud 21 degrees before TDC" Its under "advice from the pros" Does this mean there are two sensors? One counting teeth and one counting the stud? Or is it a single sensor that changes the signal as the stud goes by? (like a 60 minus 2 wheel does.
I just posted on the Innovate website and will post the reply here http://www.innovatemotorsports.com/f...ead.php?t=2743
I just posted on the Innovate website and will post the reply here http://www.innovatemotorsports.com/f...ead.php?t=2743
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Received the following response on the Innovate website.
The LMA-3 Beta 4 firmware can handle up to 60 teeth (Motronic 60-2 trigger wheel). But if you have the secondary sensor (the "stud") sensor at 21 deg BTDC, you should be able to use that signal and the ign. signal itself. Use a GM HEI module as described in the manual as amplifier and pulse former for that stud sensor IF it is a VR sensor, not hall effect. Then you can program the LMA-3 as if you had a single pulse wheel. You need to experiment with the edge to be detected as well, both for the ign. signal and the sensor signal to get it right. A timing light should be used for verification of the setup.
Regards,
Klaus
If anyone has an LMA-3 and can check this out, please post here. I have the LM-1 and will be buying the LMA-3 and the GM part. I am picking up my 951 this weekend, so it will take me a couple of weeks to check this out.
The LMA-3 Beta 4 firmware can handle up to 60 teeth (Motronic 60-2 trigger wheel). But if you have the secondary sensor (the "stud") sensor at 21 deg BTDC, you should be able to use that signal and the ign. signal itself. Use a GM HEI module as described in the manual as amplifier and pulse former for that stud sensor IF it is a VR sensor, not hall effect. Then you can program the LMA-3 as if you had a single pulse wheel. You need to experiment with the edge to be detected as well, both for the ign. signal and the sensor signal to get it right. A timing light should be used for verification of the setup.
Regards,
Klaus
If anyone has an LMA-3 and can check this out, please post here. I have the LM-1 and will be buying the LMA-3 and the GM part. I am picking up my 951 this weekend, so it will take me a couple of weeks to check this out.
#27
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If you wait a while, im working on testing divider circuits for MegaSquirts, the goal being dividing the 132 pulse signal down to something more reasonable. It wont be 60, itll probably be 44 pulses (132 divided by 3). The end result will be a 44 pin wheel, plus the single TDC pulse. If the LMA3 can be configured for a 44+1 setup, theres no reason you couldnt use a similar circuit. The problem for you will be that youd need to build VR conditioners externally, since the divider chips need the conditioned signal to work. The LMA3 would have its VR conditioners onboard, thus making them useless for this kind of setup.