guys mind sharing your vacuum pressure? Mines at -18. Did the intercooler noisemaker delete. Now it’s at -21
2012 r56s n18. I keep seeing other folks at -14 or no vacuum at all.
im running the p3 obd2 gauge.

 

You're referring to the intake manifold pressure from the MAP sensor?

The MAP reading on the N18s can be confusing because of the variable valve lift on the intake valves. At cold start the engine speed is regulated by the throttle body so at idle you'll see vacuum, I see around -14. Then when the engine has warmed up a bit the variable valve lift takes over and the throttle body opens all the way so the vacuum at idle jumps to about -1. I have a mechanical boost gauge that shows this, the MAP sensor reading from OBD2 shows the same thing. Somewhere there's a thread from about 3 years ago where I posted a graph from the Torque app showing this and a couple of links to some articles from BMW explaining the whole system.

Deleting the intercooler muffler (I think that's what you meant) shouldn't have any effect on this, so it could be a function of ihigher dle speed if the air temperature is colder at startup or if you have the AC turned on.

 

If you on an N18, at temperature, you shouldn't see any vacuum. (well, almost nothing)

You will only see vacuum on the N18 during cold start, and only if you let the car idle for a little while before driving. Once you start driving, engine controls go into warm mode, and no more vacuum.

I have seen anywhere between -14 to -20 during cold start on my boost gauge. So, you're normal.