Which MAP PID should I be tuning with? Big discrepency between the two

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Feb 25, 2022 | 01:46 PM

mk3cn4

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Which MAP PID should I be tuning with? Big discrepency between the two

Hi everyone, am finally doing some wideband tuning on my turbo build and have a question about which PID I should be using for the MAP because the two different PIDs vary greatly.

Pasting screenshots, but basically in my GRAPHS in HPTuners where I have been logging I have an "AFR ERROR" table configured where I am using "Manifold Absolute Pressure - 2 bar" in kPa with "RPM".

In my CHART VERSUS TIME area I am listing BOTH for comparison, both "Manifold Absolute Pressure - 2 bar" and also "Manifold Absolute Pressure [Sensor]".

In the logging, the "Manifold Absolute Pressure - 2 bar" shows 142kPa but at the same time the "Manifold Absolute Pressure [Sensor]" shows 124kPa for the same point in the timeline.

Which of these should I be logging in my HPTuners GRAPH so it's accurate when I paste this "Multiply Percent - Half" in the VE table of the tune?

It should be ~7lb. spring in the wastegate so I suspect the 142kPa is the right one because that was a brief WOT hit and makes more sense.

EDIT: both PIDs seem to line up until around 100kPa then the "2-bar" pid seems to grow double to the [sensor] PID instead of 1:1 from 100 kPa onwards.

Last edited by mk3cn4; Feb 25, 2022 at 02:09 PM.

Feb 25, 2022 | 03:44 PM

RonSSNova

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You should eliminate the standard Map from the channels and graphs.
Just use the 2bar.
Using both messes things up.

Feb 25, 2022 | 06:59 PM

mk3cn4

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Thank you. Yes from testing the "2-bar" one apparently is right when modifying the tune.

I didn't consider the [sensor] one to be a standard map (which would not exceed 100kPa) because it did reach 126.

I think the system one might be an "average" of the two since it lined up 1:1 until 100kPa and then seemed to be splitting the difference beyond.

Very happy with this Huron kit. I literally did the whole project myself, including this tuning, and car is amazingly strong already and I only have <7 PSI so far LOL. It's scary fast.