The N54 engine actually has two sensors.......a TMAP and a MAP.
One is on the intake manifold while the other is on the chargepipe before the throttle body.
The TMAP sensor is the one that measures intake temperatures (hence the prefixT = Tempature and Manifold Absolute Pressure) and I am pretty sure that is the one on the chargepipe before the throttle body.
The MAP sensor only measures intake manifold pressure and not temperature.
You are quoting material that is not specific to this engine and although it makes sense in other applications....... the N54 has some twists and turns (such as sensor placement).
In any case.....just measure your intake temperatures and see if they are dropping or not. I don't disagree that you are cooling the combustion chamber. I am just saying that your TMAP sensor will not read the cooler charge temps if it is behind your nozzles.
Our DME is know to pull timing out as intake temps rise.
That said.....there was another post on here where someone did multi nozzle direct port injection and got outstanding results with timing because of better methanol distribution......so it does work when applied correctly.....but I think that was using 6 nozzles tapped directly into the intake manifold.
You look to be using a dual nozzle approach although your nozzle location is moved further forward.....
Would be very interesting to see your results
Post up a log when you get a chance and please include AFR's and fuel trims for both banks as well as timing.
