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-   -   Map Voltage Values vs TE MAP headings (https://www.homemadeturbo.com/engine-management-10/map-voltage-values-vs-te-map-headings-21924/)

88b16civic Jun 13, 2004 09:24 PM

Map Voltage Values vs TE MAP headings
 
Im running zietronix WB w/ logger and was wondering what MAP voltages coresponded to what TE MAP headings. I realize it only matters what the ECU internal voltage reading is but i want to make sure im editing the correct columns.

leed Jun 13, 2004 09:35 PM

Re:Map Voltage Values vs TE MAP headings
 
Thats kinda a crap shoot w/o datalogging a map trace.
Ive noticed this with Hdata, Uber, CROME and TE.
I find that by idling the car and finding w/ columns effects idle the most vs what your boost/vacuum reads is a good way. Also, editing a boost column to a gross degree and then seeing at what psi reading it shows up on the WB works as well. All in all Ive notice that the MAP sensor reads lower than what my boost/vacuum gauge shows. But thats just my gauge. I think everyone knows that Autometers vary from gauge to gauge. Ive had 2 Autometer hooked up at the same time and there was a 2" vacuum difference.

HTH's
Dave




Chris Harris Jun 13, 2004 10:27 PM

Re:Map Voltage Values vs TE MAP headings
 

Originally Posted by 88b16civic
Im running zietronix WB w/ logger and was wondering what MAP voltages coresponded to what TE MAP headings. I realize it only matters what the ECU internal voltage reading is but i want to make sure im editing the correct columns.

I have found this VERY difficult to figure out...much of it is making large changes like LEED says and then change those columns accordingly. Problem is, that there is no closed loop disable, so partial throttle tuning is even harder to do. You make a change and you can kinda see what it does, but then immediately your ECU starts to adapt to the change. Also, the ECU is taking values from 4 cells and averaging them to get the injectors pulsewidth it fires. You can change one column and it will affect AFRs where you are looking, but generally you will have to change the column next to it as well.

I have found this brings varied results in partial throttle boosting as well. I can see my guage cross the threshold with AFRs in the 14.0 - 14.5 range unless I put the pedal down so Im at WOT.

Closed loop disable would be nice...afraid it's a ways away though.

ComputerJLT Jun 13, 2004 10:42 PM

Re:Map Voltage Values vs TE MAP headings
 

Originally Posted by xenocron

Originally Posted by 88b16civic
Im running zietronix WB w/ logger and was wondering what MAP voltages coresponded to what TE MAP headings. I realize it only matters what the ECU internal voltage reading is but i want to make sure im editing the correct columns.

I have found this VERY difficult to figure out...much of it is making large changes like LEED says and then change those columns accordingly. Problem is, that there is no closed loop disable, so partial throttle tuning is even harder to do. You make a change and you can kinda see what it does, but then immediately your ECU starts to adapt to the change. Also, the ECU is taking values from 4 cells and averaging them to get the injectors pulsewidth it fires. You can change one column and it will affect AFRs where you are looking, but generally you will have to change the column next to it as well.

I have found this brings varied results in partial throttle boosting as well. I can see my guage cross the threshold with AFRs in the 14.0 - 14.5 range unless I put the pedal down so Im at WOT.

Closed loop disable would be nice...afraid it's a ways away though.

well; i've noticed driving around the last few days with no speedo, that with the VSS not telling the computer anything the car doesn't go into closed loop mode as readily.

i dont know if this is just me or actually something thats happening but thats what it seems like.

88b16civic Jun 14, 2004 01:02 AM

Re:Map Voltage Values vs TE MAP headings
 
Luckily, in the car I was tuning, the autometer boost gage seemed to match up witht the columns i was making changes in, but when i looked at the map voltage output vs boost in xenocrons Tuning excel file, the map voltage coresponded to only like 3 lbs not 6 lbs like the gage said

The cars tuned now but did notice how much easier it was to tune when the ECU threw a CEL for the O2. Night and Day. The CEL would go on for like a minute and then turn off. Is this normal for try11. Also, if i unplug the stock O2 will it go into limp or just read off the tables like it was.

leed Jun 14, 2004 03:24 AM

Re:Map Voltage Values vs TE MAP headings
 
Yeah, unplugging the O2 is the way to go. Do a nice 5sec+ decel in gear to trigger the CEL, and you good.


Chris Harris Jun 14, 2004 12:46 PM

Re:Map Voltage Values vs TE MAP headings
 
Doesn't the ECU pull timing when throwing and O2 code though Leed?

leed Jun 14, 2004 04:06 PM

Re:Map Voltage Values vs TE MAP headings
 
Ya know, I believe Blundar said that once. I have no reason not to believe him, but it just doesnt 'make' sense.
Only one way to find out, gonna throw a freaking light on it under both conditions. :)

street_kings Jun 14, 2004 04:23 PM

Re:Map Voltage Values vs TE MAP headings
 
Another thing that i have learned through logging the map sensor Vs. a gauge is altitude effects. Boost gauges are Relative, whereas the MAP is absolute. This means that when i'm here in denver, it my boost gauge read 7.5 PSI, where my MAP sensor indicated 1331 mBar (19.5657 PSI - 14.7 atmospheric = ~4.9 PSI. Perhaps this is what happened with you 88b16civic?

Anyway, the method I used to make a datalogging table for my Techedge was take 2 readings: one a full VAC and one at ambient. Then, write an equation. (full VAC being idle, ambient being key on, engine off)

leed Jun 14, 2004 05:59 PM

Re:Map Voltage Values vs TE MAP headings
 

Anyway, the method I used to make a datalogging table for my Techedge was take 2 readings: one a full VAC and one at ambient. Then, write an equation. (full VAC being idle, ambient being key on, engine off)
Nice


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