Contour Enthusiasts Group Archives Forums Modifications Forced Induction Corrected gas turbine flow?

Corrected gas turbine flow? how do you calculate this? it is the value on the y coordinate of this graph

also, is the pressure ratio the same as the one you would use if you were mapping the compressor?
is this the graph that you would use to determine at what point you would recieve full spool up, or do you get that off the compressor map. i can map a compressor and see if the flow characteristics match that of a motor just fine. but how can you determine when you see full spool?

That looks a little different than what I've been seeing but it looks like it reaches it's max boost at 2.0 pressure ratio, so turning it up to 3.0+ would not benefit anything. The 1.06 A/R is obviously going to push more lbs/min at a sacrifice of lower end power. I don't see how you can identify when the turbo reaches full boost by looking at this graph though. I don't think that's what this particular graph is meant to display.

thats what i was asking. where DO you identify at what rpm a turbo will reach full spool if not on this graph.

Turbine Maps
1. Turbine Expansion Ratio ââ?¬â?? The degree of exhaust expansion
as it passes through the turbine.
Example:
Exhaust manifold pressure (EMP) = 15 psi
Turbine outlet pressure (Outlet P) = 1 psi
Atmosphere (Atmos) = 14.7 psi at sea level
ER =(EMP + Atmos)/(Outlet P + Atmos ) = (15 + 14.7)/(1 + 14.7)= 1.89

2. Turbine Corrected Flow ââ?¬â?? The turbine flow is also
corrected for temperature and pressure at the turbine inlet
(exhaust manifold).
Example:
Engine air flow (Actual Flow) = 50 lb/min
Exhaust manifold pressure (EMP) = 25 psi
Exhaust temperature (Gas Temp) = 1500�° F
Barometric Pressure (Baro) = 14.7 psi
Corrected Flow = {Actual Flow âË?Å¡([Gas Temp + 460]/519)}/{(Baro + EMP)/14.7}


Corrected Flow = {50* âË?Å¡([1500 + 460]/519)}/{(14.7 + 25)/14.7} = 36 lb/min

straight outta the garrett catalogue... thanks rara. 'preciate the help