Head flow versus boost
10-16-2006, 09:37 PM
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Head flow versus boost I'm curious how head flow effects boost. The way I see it a set of crappy flowing heads would make more boost. So will a set of good flowing heads make more power at less boost?
10-17-2006, 03:00 AM
#4
Boost is NOT just a measure of restriction. Even if the heads flow 400 cfm, you still want positive pressure in the intake and, more importantly, the cylinder. If you don't have positive pressure, you might as well not have FI.
Getting a better flowing set of heads will slightly reduce pressure in the intake and slightly increase pressure in the cylinder. If the heads, cam, and intake are good enough, you will have the same amount of positive pressure in the intake plenum and the cylinder BDC before compression, but POSITIVE pressure nonetheless.
Mike
Getting a better flowing set of heads will slightly reduce pressure in the intake and slightly increase pressure in the cylinder. If the heads, cam, and intake are good enough, you will have the same amount of positive pressure in the intake plenum and the cylinder BDC before compression, but POSITIVE pressure nonetheless.
Mike
Last edited by engineermike; 10-17-2006 at 03:06 AM.
10-17-2006, 04:43 AM
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A live example of the relationship between head flow, boost and power: the LS7 heads on my F1C Procharged 427 flow roughly 370 cfm on the intake, and the car made 773 RWHP at only 8 PSI without methanol.
10-17-2006, 07:20 AM
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Originally Posted by marco427
A live example of the relationship between head flow, boost and power: the LS7 heads on my F1C Procharged 427 flow roughly 370 cfm on the intake, and the car made 773 RWHP at only 8 PSI without methanol.
thats what im talking about
i bet thats a fun one to drive 
10-17-2006, 08:43 AM
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so for a 370ci w/ ls6 intake. is it worth spending the extra $$ to have a set of heads ported??
given the same amount of boost. say 13psi. what would be a ball park figure on a stock set of 317 heads vs ported 317 heads that flow say 301cfm.
given the same amount of boost. say 13psi. what would be a ball park figure on a stock set of 317 heads vs ported 317 heads that flow say 301cfm.
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10-17-2006, 07:27 PM
#9
Originally Posted by T/A KID
I say skip the heads and get the bigger blower. Crank the boost as high as you can before detonation.
I like that thought.. The way I look at it.. Crank it till it blows. Then you can build a better block with some better heads!!
