I've messed with engines for years, but never got much into tuning. I am trying to understand how a change in map sensor, for instance going from a 2.5bar to say a 4 bar, will affect tuning if I'm still within stock limits. Iirc an r53 makes 10-11 psi of boost. With a 15% overdrive pulley is around 15. What happens if I put a 4bar map sensor on my car. Is it just reading the expanded range of values? Anyone want to educate me?

 

Well nevermind. I went researching and got educated. I was just wondering if part of my previous lean condition might have been due to limts of stock map sensor.