chip-3door,
3 bar is only a rough approximation of how much positive pressure it will read (with the first bar being atmospheric)
any pressure off absolute is a positive pressure,, even space which is around 0.0000000000000000000000001 bar
(1x10 (-25))
Mike Rainbird,
The way tuners get round this when running big boost and the 3 bar MAP sensors, is to extrapolate the afr curve and throw sufficient fuel in to suit the required boost.
isnt it interpolate mike
and it dont really know if you call you would call what they do that!
remember running boost over your map sensor isnt smart,,, it will fuel the same for 29psi the same it will for 36 psi
