[Raptor04]

Are these two values the same? The Intake Manifold Pressure can be pulled directly from the OBDII. Is this the same reading as the T-MAP sensor to measure boost or is a proprietary BMW channel used to read the T-MAP and actual boost?

[Allen@MOTIV]

T-MAP pressure is pulled from the T-MAP sensor in the charge pipe and MAP pressure is pulled from a MAP sensor in the intake. The T-MAP is a 2.5bar sensor referenced by the DME when in boost and the MAP sensor is only cappable of reading a couple of PSI and only referenced when in Vaccuum/very low loads. This is done to provide betted sensor clarity across a wider range than when only using one sensor.

Keep in mind that T-MAP sensor values are influenced by throttle plate position and can provide exaggerated values when a throttle closure occurs.

[3000GT MR]

Also just to note. Its smarter to take pressure from the manifold vs the charge pipe. If you plan on running higher than around 18 psi Its worth having a sensor added to the manifold vs upgrading the charge pipe to a 3.5bar. The pressure drop is inversely proportional to boost anything past that from my experience. So if you want true boost indication taking it from the manifold (like 99% other cars) its more accurate than the charge pipe. Luckily we naturally have a large throttle body for a stock engine but i've seen pressure drops as large as 1psi at high boost. The Procede handles a post TB MAP sensor real well and transitions so smooth you cant feel or see it on logs. With an inverse ratio of boost and pressure loss this is very important as tuning becomes more difficult.