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has any one tried fitting a second map sensor just for boost with 12p as when you go to a 2 or 3 bar sensor you loose res in the map. just a thought maybe keep the 1 bar for off boost and switch to the 2-3 bar on a flex input or is this too hard to set up? might make some boosted cars nicer to tune.

you obviously haven't seen the $12P ve and boost ve tables then ? the only way you loose resolution is if you go to 3 bar but then you move through the boost ve table so quick it doesn't matter!

Technically, the 0-5v input is scaled differently for 1 2 and 3 bar, but that type of resolution loss is not the same resolution loss like in the old school 2 bar $5d tune which lost a lot more resolution by not enlarging the maps in the tune. For 12p its not a limiting factor.

You do lose some resolution behind the scenes due to the scaling but its not terrible. We only have 8 bits to work with, so 256 resolvable steps from 10-104.4kPa, 8-207kPa or 2.2-313kPa. It wont get the full 8 bits due to a number of factors but will be reasonably close. Lets say its really bad and loses a whole bit, so its 7 bits and 128 steps. Even then for 1-bar we can resolve around 0.7kPa, 2bar around 1.5kPa and 3 bar around 2.4kPa. Thats probably a worst case though.

You can run two different MAP sensors with map a and map b but switching with the engine running I have never tried and could be risky if you get a sudden lean spike as it comes on boost - I would also need to check the code if there are any 2/3 bar MAP variables that get calc'd at boot up only.

And I think if I'm right that 2.4 kpa equates to .35psi resolution ? Which would mean pretty much 3 cells of adjustment for every psi of boost!!

I agree you get to boost so fast who cares. My car is running great with 12P and hits boost so quickly I don't think I would even consider how it performs under boost.

I've done very little tuning to my boost ve table and its following the commanded afr almost perfectly!!

that was the answer I was looking for. the question was asked of me by a friend wanting to boost a falcon 6 with a delco with 12p

Its interpolates between the table too, does not jump from one cell to the next

Tell him the only thing he needs to know is the delco will make his ford more reliable and simply by using it he'd have to gain at least 10hp