[Tom Vaught]

So HOW HOT does that Pontiac Blow thru Carb get? Show you a bit more math today.

Example: the inlet temperature is 70 deg F, the suction pressure is -0.5 psig (a slight vacuum due to Inlet Plumbing), the discharge pressure is 19 psig, and the efficiency is 72%. What is the discharge temperature?

Tin= 70 deg F + 460 = 530 deg R
Pin= -0.5 psig + 14.7 = 14.2 psia
Pout= 19 psig + 14.7 = 33.7 psia
Pout/Pin = 33.7/14.2 = 2.373 (this is the pressure ratio)
Tout = (530 + 530 x (-1+(2.3730) raised to the power of .263 ))) all of this divided by 0.72
= 717.8 deg R - 460 = 257.8 deg F
So the theoretical outlet temperature is 257.8 deg F. I sure would like to have an intercooler to cool that hot air down before it goes into my engine.

So assuming a 70% efficient inter-cooler

257 deg F – 70 deg F ambient temp = 187.886 deg F Temp rise from the turbocharger compressor

So if you have a 70% efficient inter-cooler: 188 deg f times .70 = 131 degrees of temp removal

So the discharger air out of the intercooler is 56 deg f hotter than ambient temp to the actual air
Temp going into the engine is 126 degrees at 19 psi boost pressure

This time I think the math will be easy to follow.

Tom V.