[robertm]

Originally Posted by RnmEvo9

Monitoring boost levels is crucial even with OEM turbos. I have my 135i modified and I can easily tell if I am hitting my boost targets and/or if I have a boost leak/vacuum leak. If I suspect there is a problem, I can easily check on it to fix the issue. I can also monitor ignition timing in real time which lets me know if timing is being pulled during a pull. This can be due to bad gas or other factors, but the fact is that it will let me know if my car is running optimal or not. It also has a built in code reader so that whenever a check engine light appears, you will know exactly why it threw a code instead of taking it in at a BMW dealership and having them pull the code for you and maybe charging a diagnostic fee lol. Intake air temperatures and exhaust gas temperatures are important parameters to monitor when you are modified as you don't want those temps to be too high.

This.