Speed Density MAT
#46
Newbie
So is what you mean is that MUT 11 should have the address 9a96 from the 139 element table? Without looking I'm almost certain that's not the address that's currently in there because I've looked over that table and nearly everything starts with an '8'. Lemme check and get back here later.
The MUT table you show in your follow-up post has the stock 94170015 addresses for MUT 11 (0xFFFF88C1, shortened in the ECUFlash presentation to 88C1) and MUT 3A (0xFFFF88BD, shortened to 88BD), so when you log MUT 11 you are logging the scaled IAT (i.e. output from interpolating the IAT sensor calibration map) and on MUT 3A you are logging the raw IAT sensor ADC input voltage. If you set the eval formula for each MUT appropriately in Evoscan you would then be able to cross check that the IAT calibration map is producing the correct output on MUT 11 given the input from MUT 3A.
I did have a look for fuel temp info as well: the only standard MUT item in 94170015 for this seems to be the raw fuel temperature ADC input voltage on MUT 87. If you were to pick a MUT item that you have never logged and change the address in the MUT table to 8917 (enter as 0x8917, this being the shortened form of the real address which is 0xFFFF8917) you should be able to log the value interpolated from the fuel temperature sensor calibration table with the Evoscan eval formula x*1.8-40 (for °F). Looking at your MUT table, I would pick one of MUT BC, MUT BD or MUT BE for this purpose as these are duplicates of MUT BB (NB: you can only select a MUT to change from MUT 00 through MUT BF as these are MUT requests; the higher MUTs are all commands).
#47
Evolving Member
Thanks for clarifying, I misunderstood. I'm going to have to cross reference 3a and 11 logged values and see if one is appropriate given the logged value of the other. I've got the correct evaluation formulas for each request. X*1.8+32 for 3a and x*1.8-40 for request 11 for deg F.
I noticed if I use 0x03 I log about 10 degrees under ambient at 3a and if I use 0x0E (preferred for my tune), I log about 10 degrees OVER ambient at 3a. Either setting yields 73-75 degrees at request 11. I'm thinking somehow my table scaling may be off or the ait senor is bad.
I don't know how guys are logging within a degree of ambient/coolant temp on a stone cold car, at request 11. I'll figure this out if it kills me.
You've seen my scaling tables for mat (121 element) and sd mat scaling for iat table(139 element) does anything look glaringly off for a gm ait? The table scalings I've found for temp and volts are few and far between and all the old threads with appropriate scales and patches have DEAD links.
Again, thanks so much for your help and time here. I'm still learning.
I noticed if I use 0x03 I log about 10 degrees under ambient at 3a and if I use 0x0E (preferred for my tune), I log about 10 degrees OVER ambient at 3a. Either setting yields 73-75 degrees at request 11. I'm thinking somehow my table scaling may be off or the ait senor is bad.
I don't know how guys are logging within a degree of ambient/coolant temp on a stone cold car, at request 11. I'll figure this out if it kills me.
You've seen my scaling tables for mat (121 element) and sd mat scaling for iat table(139 element) does anything look glaringly off for a gm ait? The table scalings I've found for temp and volts are few and far between and all the old threads with appropriate scales and patches have DEAD links.
Again, thanks so much for your help and time here. I'm still learning.
#48
Evolving Member
Well, I still seem to be logging strange values. I've tried intentionally different settings in the MAT Scaling table (121 element) and 131 element SD MAT scaling for IAT scaling table and obviously logged request 11 changes with adjustments to the SD MAT/IAT table.
What's interesting is that request 09, 87 do not change based on completely different scaling settings for the MAT table with tempscalefuel scaling.
Air temp remains well above ambient by more than 15 degrees and logged fuel temp is logging 221 degrees F? I went with MUTBC with address 8917 to log fuel temperature per your recommendation.
There must be some scaling issue here. I wish there were some definitive and convincing table scaling values that were shared in some of these threads and the old links are all gone.
What's interesting is that request 09, 87 do not change based on completely different scaling settings for the MAT table with tempscalefuel scaling.
Air temp remains well above ambient by more than 15 degrees and logged fuel temp is logging 221 degrees F? I went with MUTBC with address 8917 to log fuel temperature per your recommendation.
There must be some scaling issue here. I wish there were some definitive and convincing table scaling values that were shared in some of these threads and the old links are all gone.
#49
Newbie
Thanks for clarifying, I misunderstood. I'm going to have to cross reference 3a and 11 logged values and see if one is appropriate given the logged value of the other. I've got the correct evaluation formulas for each request. X*1.8+32 for 3a and x*1.8-40 for request 11 for deg F.
I noticed if I use 0x03 I log about 10 degrees under ambient at 3a and if I use 0x0E (preferred for my tune), I log about 10 degrees OVER ambient at 3a. Either setting yields 73-75 degrees at request 11. I'm thinking somehow my table scaling may be off or the ait senor is bad.
Which input on the ECU do you have your GM AIT wired into? If the GM AIT is wired in place of the stock MAF AIT, then MUT 3A and MUT 11 will tell you about it. If you're setting the SD routines to use the fuel temp rather than AIT then you'll need to log fuel temp related data (as described in my earlier post) to understand what the SD system is doing.
#50
Evolving Member
Thanks for the formula for logging volts from the air temps sensor! I was wondering about that and couldn't seem to find it amongst the threads I'd searched. I'll give it a shot and then I can correlate volts in 3a to the temp logged at mut11.
I was under the impression that if I'm logging fuel temp with option 0x0E and still have my GM iat sensor connected to the maf harness via the Spoolinup adapter, the value logged at MUT11 is a simulated fuel temp converted from raw iat? Something along those lines. I think I read that more than once in one of the original MrFred threads on SD logging mat, etc.
I'm still going to attempt to log fuel temp using mutBD using address 8917. I tried address BC yesterday and logged 200 plus deg F which is incredibly off for some reason or another.
I have no explanation as to why my logs for raw iat at 3a change up and down 10-11 deg F from ambient just from changing 0x03 to 0x0E but it does. I tested it back to back with that being the only change to the rom! Strange...
I was under the impression that if I'm logging fuel temp with option 0x0E and still have my GM iat sensor connected to the maf harness via the Spoolinup adapter, the value logged at MUT11 is a simulated fuel temp converted from raw iat? Something along those lines. I think I read that more than once in one of the original MrFred threads on SD logging mat, etc.
I'm still going to attempt to log fuel temp using mutBD using address 8917. I tried address BC yesterday and logged 200 plus deg F which is incredibly off for some reason or another.
I have no explanation as to why my logs for raw iat at 3a change up and down 10-11 deg F from ambient just from changing 0x03 to 0x0E but it does. I tested it back to back with that being the only change to the rom! Strange...
Thread
Thread Starter
Forum
Replies
Last Post
scheides
ECU Flash
357
Oct 22, 2021 08:59 AM
2winscroll
General Engine Management / Tuning Forum
2
Feb 16, 2017 01:39 PM