Speed Density IAT options
bump to confirm the proper scalings when using the fuel temp sensor (not splicing the GM IAT into the fuel temp ADC) and also where those scalings should be edited in ecuflash.
I'm making the plunge into SD and downloaded the 8859 3d 2.0 rom, I've got the car running and the selection is to use the fuel temp input but I want to confirm the scalings for the sensor are correct. I've looked and the fuel temp scalings, mat scalings, and SD IAT scalings are all different.
Input appreciated!
-Eric
I'm making the plunge into SD and downloaded the 8859 3d 2.0 rom, I've got the car running and the selection is to use the fuel temp input but I want to confirm the scalings for the sensor are correct. I've looked and the fuel temp scalings, mat scalings, and SD IAT scalings are all different.
Input appreciated!
-Eric
Newbie
Joined: Nov 2011
Posts: 42
Likes: 0
From: East Coast
I believe this is all the correct info for:
GM IAT sensor connected to MAF harness (temps are in Fahrenheit)
via Spoolinup SD IAT Plug n' Play Harness or hardwiring the sensor to the harness by connecting it to the RED/BLUE wire and the BLACK wire.
I want to make sure this is correct for everyone else before I finalize the info for this option.
GM IAT sensor connected to MAF harness (temps are in Fahrenheit)
via Spoolinup SD IAT Plug n' Play Harness or hardwiring the sensor to the harness by connecting it to the RED/BLUE wire and the BLACK wire.
- SD IAT option set to 0x03
- SD MAT Scaling for IAT Scaling located in the Speed Density Programming section in ECUFlash needs to be sure the temp scaling for the table is set properly before editing any values. The correct scaling needs to be set to TempScale. The window bleow can be found by RIGHT-CLICKING the table and selecting "EDIT MAP...".
- Once the table scaling is confirmed to be set correctly, you need to confirm that the appropriate temperature scaling for the GM IAT in the right column of the table is set to the proper values. The correct values can be found HERE. If they don't already match the values currently in the table, copy and paste the values from the link provided.
- In evoscan, use MUT11 to log the actual air temp readings that will be used by the ECU in all of the maps when the car is running. MUT3A is the unscaled raw air temperature directly from the sensor itself. Here is the evoscan data if you do not have them already:
Code:
<DataListItem DataLog="Y" Color="" Display="Air Temperature" LogReference="AirTemp" RequestID="3a" Eval="1.8*x+32" Unit="deg F" MetricEval="x" MetricUnit="deg C" ResponseBytes="1" GaugeMin="0" GaugeMax="190" ChartMin="0" ChartMax="190" ScalingFactor="1" Notes=" " Priority="1" Visible="False" /> <DataListItem DataLog="N" Color="" Display="MAF Air Temp Scaled" LogReference="MAFAirTempScaled" RequestID="11" Eval="1.8*x-40" Unit="deg F" MetricEval="x-40" MetricUnit="deg C" ResponseBytes="1" GaugeMin="-40" GaugeMax="260" ChartMin="-40" ChartMax="260" ScalingFactor="1" Notes="" Priority="1" Visible="False" />
Newbie
Joined: Nov 2011
Posts: 42
Likes: 0
From: East Coast
I switched to IAT sensor because the fuel temp sensor was always 20 to 30 degrees off and it would screw up my afr's...The fue temp sensor was setup volts adcx4 scaling.....Is the uicp the ideal place for the iat sensor? I wanted to place it after the intake filter just like the factory just wondering if that was a bad idea? its also further from the engine less heat soak i thought....Thanks again
I switched to IAT sensor because the fuel temp sensor was always 20 to 30 degrees off and it would screw up my afr's...The fue temp sensor was setup volts adcx4 scaling.....Is the uicp the ideal place for the iat sensor? I wanted to place it after the intake filter just like the factory just wondering if that was a bad idea? its also further from the engine less heat soak i thought....Thanks again
-Jamie
Newbie
Joined: Nov 2011
Posts: 42
Likes: 0
From: East Coast
I'am not a guru but if you have an evo 8-9 and your running 88591715 you need to make sure under speed density programming in the ROM the SD convert IAT to MAT is set to (0E) if not you must change it by entering it in the hex form 0x0E. The sensor is already wired in to the ecu all you are changing is the location where the ecu gets its information from. I have done both and the IAT sensor in the uicp coming off of the intercooler is the most accurate in my opinion but for that you have to get a gm iat sensor, weld bung, plug and play harness.... I hope this helps good luck
evo7 didnt have fuel temp sensor ,you could wire it to the maf plug wiring , red/blue wire goes to pin 72 ecu and and black wire goes to pin 92 ecu
Evolved Member
Joined: May 2010
Posts: 500
Likes: 4
From: Australia
Running OK using MAF IAT, will be using spoolinup IAT and the scaling provided here. Hopefully works ok just need to find a place for the sensor as I am not drilling my piping. Can I situate it low and forward near the cooler perhaps?
Last edited by EvocentriK; Jul 29, 2013 at 10:13 AM.
im using jdm9 mat in the inlet manifold