alright im almost there. ill tell you guys what i have done and what i dont have done. i have the Pressure ratio down. 14.7+boost/divided 14.7 =Pressure ratio absolute. is that right? that will deterime if i want a turbo at low boost or high boost? is that correct? the only thing i understand about the surge limit is that it is bad and do not want to be on the left side of it. i do not understand how you get the air flow or CFM. i also understand at the right side of the map those numbers are compressors RPM. i do not understand what that red line is and why there is percentage in the middle of the islands. and i dont understand what the islands are. i read all that stuff nd still dont understand can somebody please explain it to me. and i have one more question. are all the compressor maps based on Pressure ratio and Airflow. or is there other stuff that they can put at the X and Y axis other than Pressure ratio and CFM airflow?

 

https://honda-tech.com/zeroforum/16