N54 Boost setpoint parameter

veer90

Lieutenant
Nov 16, 2016
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West Nyack, NY
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e90 335i 6MT
Can someone explain to me what exactly the values mean for this parameter?

I know it's the Y-axis for certain WGDC tables and seems to hover around 2.2 - 2.5 under full load. Other than that, not really sure what the DME is doing with that information or what values correspond with what scenarios.
 

Tiron

Lurker
Oct 10, 2018
23
25
0
Ride
BMW 135i
I assumed it was essentially requested boost (really requested manifold pressure, maybe requested charge pipe pressure), so 1.0 would be baro pressure and anything above that would be boost, less would be vacuum. I could be wrong on this.

Assuming it works the way I think it does, baro where I live is usually ~85 kPa, so 2.2 would be 85 * 1.2 = 102 kPa or about 14psi of req boost for me. Its been some time since I logged this parameter directly though. Honestly it doesn't matter much what it means, you should be using data logs to know where to make any corrections in the tune -- which would give you the EXACT setpoint value you need to modify.