Im wondering what has everyone been seeing for stock boost on their GPs? I just put my BMS can tool in and hijacked the speedo for boost. I seem to be hitting peak 16psi. Can this be right? Seems high for the car being stock..

 

Peak boost is actually much higher. The boost level depends to some degree on what the ambient atmospheric pressure is, but the peak is around 21psi of boost.

However, the ECU only makes as much boost as it needs to in order to achieve its target power levels within safety parameters. This will depend on lots of factors, eg ambient and air intake temperature. In full throttle street runs I normally see a peak of around 16psi. On the racetrack with repeated and prolonged full throttle, heat soak of the intercooler, high intake temps etc I have seen up to 21psi frequently.

Don't forget that the N18 JCW engine runs the highest boost of any current BMW engine, and makes more horspower and torque per cc of engine capacity than any current engine BMW , including all the M engines. It is a pretty highly tuned beast

 

Try doing a pull in 4th gear so you have some load on the engine. I would expect you'd see higher boost levels. Yep... it's a little ridiculous considering these are also 10.5:1 compression engines. DI is an amazing technology.