| .. adding in turbocharger discharge temperature based on different ambient temperatures... Turbocharger Discharge Temp @ 60F and 90F Inlet Temp 90F Inlet Temp 14.5psi(a) inlet pressure 14.5psi(g) boost 74% efficiency Discharge Temp: 251F, 121.7C 60F Inlet Temp 14.5psi(a) inlet pressure 14.5psi(g) boost 74% efficiency Discharge Temp: 212F, 100C Intercooler discharge density from turbo discharge temp, ambient temp, pressure, and IC efficiency:
90F Ambient Temp 14.5psi boost 121.7C turbo discharge temp 90% IC eff 32.2C (90F) ambient temp 41.15C ICTOUT Density: 2.2137kg/m^3 60F Ambient Temp 14.5psi boost 100C discharge temp (212F) 90% IC eff 15.5 ambient temp (60F) 24C ICTOUT Density: 2.3414 5.8% difference in actual air density at intercooler discharge SAE is 3.3% They disagree by 2.5%. All the SAE correction factor is accounting for is the density of the air as ambient temperature and pressure change. Changes in humidity are also taken into account but I would imagine that the effect of changes in humidity are going to play a very small role as compared to temp and pressure. The calculations above are figuring what the difference in air density is at the intercooler discharge, which is essentially what the SAE correction factor is accounting for in the ambient air but you can clearly see that there are discrepencies when dealing with turbocharged and forced induction applications.

[ ashspecz.com ] [ agpowers@bellsouth.net ] Enthusiasts soon understand each other. --W. Irving. Are you an enthusiast? If you are out to describe the truth, leave elegance to the tailor. Albert Einstein
|