cfm at certain times?
Thread Starter
Racer
Joined: Nov 2006
Posts: 270
Likes: 4
From: columbia mo
cfm at certain times?
I was wondering what the stock motor sucks at:
Idle?
Mid-range rpm's?
WOT?
If someone knows anything about the cfm's the engine sucks and I am asking the wrong question above, just kick me and tell me what I really need to know.....in detail too(I learn fast)
thanks
tyler
Idle?
Mid-range rpm's?
WOT?
If someone knows anything about the cfm's the engine sucks and I am asking the wrong question above, just kick me and tell me what I really need to know.....in detail too(I learn fast)
thanks
tyler
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Assuming a BSFC of .5 and a 240chp SBC engine, flow needed to build rated peak hp is:
CFM = (240 * .5 * 8) / (8 * .8 * .443) = 960 / 2.84 =~340cfm
The flow needed realy depends on how much HP the engine is building not on throttle position.
For example when you snap the throttle wide open at idle the engine will rev up its power curve but can only take as much air as the engine demands, depending on rpm, i.e. where is the engine on the power curve.
CFM = (240 * .5 * 8) / (8 * .8 * .443) = 960 / 2.84 =~340cfm
The flow needed realy depends on how much HP the engine is building not on throttle position.
For example when you snap the throttle wide open at idle the engine will rev up its power curve but can only take as much air as the engine demands, depending on rpm, i.e. where is the engine on the power curve.
Racer
Joined: May 2006
Posts: 293
Likes: 0
Originally Posted by 65Z01
Assuming a BSFC of .5 and a 240chp SBC engine, flow needed to build rated peak hp is:
CFM = (240 * .5 * 8) / (8 * .8 * .443) = 960 / 2.84 =~340cfm
CFM = (240 * .5 * 8) / (8 * .8 * .443) = 960 / 2.84 =~340cfm
I don't know what the denominator is. It looks like 8 cylinders times a V.E. of 80% times ??? whatever the constant .443 represents.
How does that formula work? Can you explain it for us please?
Race Director
Joined: Sep 2003
Posts: 16,838
Likes: 341
From: Database Error Indiana
I was wondering what the stock motor sucks at:
Idle?
Mid-range rpm's?
WOT?
If someone knows anything about the cfm's the engine sucks and I am asking the wrong question above, just kick me and tell me what I really need to know.....in detail too(I learn fast)
thanks
tyler
Idle?
Mid-range rpm's?
WOT?
If someone knows anything about the cfm's the engine sucks and I am asking the wrong question above, just kick me and tell me what I really need to know.....in detail too(I learn fast)
thanks
tyler
I dont know about forced induction, but there is a forum here with some very sharp guys that can help.
