Turbo airflow numbers

[Forrest]

Was checking out the Holset site on specs for the HX35, HX40 & HX55. Click on "Current Products", then "X Range".



http://www.holset.co.uk/flash/index.html



Airflow is rated in kg/s:



HX35 ... 0. 46

HX40 ... 0. 53

HX55 ... 0. 75



Not so big a % jump between the HX35 & HX40, but between the HX40 & HX55 ...



So exactly what does this mean for us? Does this mean for a given PSI, let's say @ 40psi on our boost guages, the bigger the Airflow the more air is getting packed in the cylinder?

 

[CFAR]

From what I understand (hehe not much usually) its not that more air is being forced into the cylinders its that the charge air is cooler. At least at for us guys running 30-40 psi.



If you think about it, it makes sense, 40psi is 40psi, unless you are using bigger hoses, or ported intake, you can only flow so much air. But if the compressor is more efficient at 40psi, then the air will be cooler, which does mean more air.



Does any of this make sense?

 

[Bob V]

Remember, whatever your drive pressure is, that pressure is left in the combustion chamber when the exhaust closes/intake opens. So if your drive pressure is higher with a smaller turbo you are getting less air at the same pressure.

 

[BPonci]

HX30=. 35 HX35=. 46 HX40=. 53 HX50=. 75 HX55=. 75 HX60. 95 HX82/83=1. 5