Exhaust gases
 

hi, I have a question. I have just calculated what is my engine airflow at what RPM, now I need to determine what turbo I need.
The problem is that I am not sure whether my engine that will get 10lbs/min at 4500RPM (5PSI) of air will produce 10lbs/min of exhaust hases that will spin up the turbine. Is there any rati or what comes in it comes out ???

Other questions is fuel management - is there any ratio that I can use to determina how much fuel I need for how much boost?
If I am not wrong it is: 20% of air pushed to engine (~20% is oxygene) and if I am not wrong optimal air/fuel ratio is 11,4-11,6/1 does it mean that for 10lbs/min of air (2lbs/min of oxygene) I will need 0,173lbs/min of fuel? Is that correct?

Thanks for replies