4G63_Fiend

So I am new to Evo's and have been seeing that in order to log boost, the JDM or Evo X 3 Bar MAP sensor is needed. I get that part! My question is, WHY? Or even more so HOW does it make sense for the ECU to not know boost pressure?

Doing searches, all I can find is what needs to be done in order to log boost, which is great stuff and will be performing the sensor swap soon on mine. I guess I like to have a better understanding of why things work, which helps me in the how department when it comes to vehicle systems.

Sorry if there is already info out there on this, I just didn't see anything. So if there is some info that I missed, please don't kill me!! Lol

Thanks for the input!

Biggiesacks

the ecu in stock form uses calculated load instead of a direct measurement of manifold pressure. It calculates that load based on several different sensor readings and variables.

4G63_Fiend

That's kinda what I figured. Any idea what sensors it uses to collect that data?

4dooradam

been wondering the same thing actually. But i just figure the computer still knows exactly how much air is being consumed anyways by the maf sensor so i guess it really doesnt absolutly need to know exactly what the boost is since it still knows how much air is going in.

LetsGetThisDone

iTrader: (1)

It has a mass air flow sensor. It knows how much air is going in. It doesn't need to know boost pressure.

wreckleford

iTrader: (2)

Yup. The factory boost control implementation controls load and not boost pressure, so should really be called load control and not boost control.