Compressor flow question

[UndergroundR32]

What is the relationship of pounds per minute of flow translated as cubic feet per minute of flow. I.E. 1 lbs/min = ?cfm of flow?
My appologies if this is a newbie question.

 

[GSX4LIFE]

Not sure of the direct corralation, but the Green uses a 49lb. wheel and flows 730cfm. The L2R uses a 54b. wheel and flows about 850cfm(w/ the E-housing.) Based on this info I would assume that 1 LB. per minute of air equals about 14.9cfm. I came up with this by doing the formula as follows: 730 devided by 49 = 14.897959, so round to 14.9. If you use this formula with the L2Rs 54lb. wheel, you will get 805cfm. Add the larger E compressor housing(About 40 cfm more airflow) and the end result will be 845cfm. Pretty close. I culd be wrong about this. My Volumetric Geometry, and airflow calculation formulas are not the best. But I think I may be very close.

 

[UndergroundR32]

Yeah I knew the lbs/min and cfm of flow for the l2r. I was just wondering what the exact relationship was between the two measurements. As far as I can tell what you said makes pretty good sense, but like you I could be wrong as well . The main reason I asked is because it's easier for me to understand CFM than lbs/min. Maybe you could explain to me how that would work when 54lbs/min of air is said to flow. I mean, how would you flow 54 pounds of pressure (per square inch I would assume) through an open space? That seems to me to tell only the force at which it's being thrusted through at, not the amount of air which is traveling.

 

[GSX4LIFE]

All wheels are rated at thier max efficiency values. For instance a 16G is rated at 505 cfm at approx. 15 psi. This is because it is not super efficent at anything over 15psi. Will it spool more than this? Hell yes. But not at the efficiency leval intended. So all turbos work the same. They are given a max cfm value based on thier efficiency max boost leval. It is different for every turbo. The L2R is rated at 54lbs of airflow per minute. I can ot tell you at what boost pressure that is. It must be at its maximum efficient leval. And Im not sure how that is calculated either. Is 60% efficient? Is 70%? Is 80%. I think they are all different, but it gives you a little better understanding.

 

[UndergroundR32]

When you say that 505 CFM at 15 psi is it's boost of maximum efficiency of flow does that mean it spools to its max flow rate quicker than any other boost setting would for their maximum flow?

 

[GSX4LIFE]

No, what I mean is that a turbo will flow more cfm or lb per mins at 20psi than at 15 psi. But if its not being done efficiently, that 20 psi or XXX amount of airflow will yeild no more power, because it will be hot air literally. Useless. I tried to AOL you. But your not on. Hit me up at cpln5 on AOL IM.

 

[IPT]

All turbos are rated at 1.0 Bar which is 14.7 psi of boost. It is just a standard reference point.

The lb/min rating is the most air that the turbo can flow. It may all be hot air, but it would flow that much. When looking at a compressor map it is the farthest point on the right.

 

[swordfish]

lbs/min = .075 X CFM

You can derive CFM or lbs/min from the above equation gvien you have one or the other.
For Example:
49 lbs/min = .075 X CFM so CFM = 49 lbs/min/.075 so CFM = ~653

jeff

 

[UndergroundR32]

Originally posted by swordfish
lbs/min = .075 X CFM

You can derive CFM or lbs/min from the above equation gvien you have one or the other.

jeff

Thank you, that is exactly what I was looking for

 

[DCJ98GST]

Originally posted by swordfish
lbs/min = .075 X CFM

You can derive CFM or lbs/min from the above equation gvien you have one or the other.
For Example:
49 lbs/min = .075 X CFM so CFM = 49 lbs/min/.075 so CFM = ~653

At what temperature?