So I'm trying to scale a new map sensor, and i can't quite get it to match my Defi electronic boost gauge.
It's a 3bar Bosch unit which has a datasheet that shows a linear slope and 0.4v at 20kpa and 4.65v at 300kpa.
From doing the maths, checking a few online posts, and even tried using chatGPT for another source, I get a slope and offset of
Code:
65.88235kpa or 9.55427psi
-6.35294kpa or -0.92142psi
This gets me 0 at KOEO and nearly matches vacuum on my external gauge at idle.
However, at ~1bar of boost, it is slightly off (logs show ~0.92bar).
I adjusted the offset and ended up with
Code:
-6.1461kpa or -0.89142psi
Which got me closer, showing 0 at KOEO, -0.84 on decel (matching external gauge) and 1.044bar (external gauge showed 1.1 on the dot).
Should I keep playing with the settings to try and get the MAP to match the external gauge?
Should I just go with the setting calculated from the datasheet and ignore the difference to the Defi
Is that much of a difference worth chasing?
