Map Scaling Help

[tune time]

Could some one direct me in the rite way to scale a map sensor. Such as what I need to do and what formula to use. I have a Zeitronis 3.5 bar that I am trying to set up in a 2003 vett ecm thanks for the help.

[LSxpwrdZ]

Gonna be hard to use that map sensor because changing the map calibrations wont extend the breakpoints on the VE table. You could upgrade to a 3bar OS and then go into the Eng. Diag. tab and input the map sensor specs in the airflow sub-tab. The stock calibration has the parameter to adjust the map sensor calibrations but for whatever reason HPT wont allow us to modify it unless you upgrade to a custom OS.

[tune time]

Gonna be hard to use that map sensor because changing the map calibrations wont extend the breakpoints on the VE table. You could upgrade to a 3bar OS and then go into the Eng. Diag. tab and input the map sensor specs in the airflow sub-tab. The stock calibration has the parameter to adjust the map sensor calibrations but for whatever reason HPT wont allow us to modify it unless you upgrade to a custom OS.

I will be going to the new OS system it is being used on a d1sc procharger system I will only be going to about 14 psi any way but I im just useing this map to try it out I have had several guys tell me thatit is a really accurate map and the 3.5 bar is as small as they make I have a mighty vave and a pressure sorce I just need to know how to scall it. the paper work says it is as follows

0 psi is = to 0.5v
50 psi is = to 4.5v

Thanks for any help

[Frost]

your results will be much better with a 2bar OS and sensor...

[tune time]

your results will be much better with a 2bar OS and sensor...

Yes I realize that my resolution will be a lot higher. And I am trying to find a 30 pound absolute quility sensor that will give me -14.7 psi all the way to +15.3 psi I have the number but no one stocks it. It is a lab quility unit mad by kavilco. But I still can not find a how to or anyone that can tell me the rite way to scall a map sensor . Thanks for the input though.

[Frost]

You posted the offset and linear values in the previous post I thought. The linear value is the slope per 5v of range. The offset is the actual kPa value reported at 0 VDC. The sensor must read vacuum for N/A driving of course.

[Pyros777]

What sensor are you using? (brand/model number)

[Pyros777]

Just going off the numbers you posted, it looks like these *should* work for you:

Linear: 382.598125
Offset: -43.458719

Despite the 6 decimal place accuracy, these are still only ballpark numbers. I generated them by comparing the data from a couple OEM tunes versus the sensors (LSJ & LNF GMS1, 0 261 230 042 & 0 281 002 845 respectively) advertised ratings, checked the differences (within .99 and 1.1), and applied them to the data you posted.

Its a "best guess" approach since I've never really seen a documented method for scaling MAP sensors, but I imagine it will get you very close. Here it is plotted just to get an idea:




Note: Something about 0psi @ 0.5v feels off, but that is why I would like to see where you got that from. It could be correct though, given the lower resolution of this larger sensor.

[blownbluez06]

for your offset, put the sensor in and bump the starter while watching the scanner. Keep the fuel pump relay out and watch the Kpa during the startup. Adjust the offset until you get 100kpa.
You can do all the math you like, but when it comes down to it, you're most likely going to need to do this to verify you're in the right place at startup.

[Frost]

for your offset, put the sensor in and bump the starter while watching the scanner. Keep the fuel pump relay out and watch the Kpa during the startup. Adjust the offset until you get 100kpa.
You can do all the math you like, but when it comes down to it, you're most likely going to need to do this to verify you're in the right place at startup.

That gets you close; some may say good enough for gov't work. If you are being picky, start with the one bar MAP and OEM OS. Record it's value. Now use your method to match the new sensor to the 1bar value.