How many CFM does it flow?

 

i've been told that it is 780cfm, but like you i'm interested in knowing if that is actually the correct number or not. very good question grippy...

 

In a recent GMHTP they stated a stock LS6 TB cfm @ 800.

Ours is comparable? yes/no?

 

Doesnt it flow as much as you can force through it?

 

Stock truck 78MM throttlebody has the same sized opening and should flow the same as a stock LS6 throttlebody.From what I understand a 90mm throttlebody can flow over 1100CFM.

 

That's where the Centrfi guys and the turbo guys have a slight advantage.....however the KB, Whipple, Radix guys are stuck with the dreadful "draw through" style system.....So in answer to your question, Yes and No. There are some pumping losses associated with what I am talking about, this will transfer into heat and parasitic loss.

 

Cooool, thats some good cfm.

Any idea what size tb is on the LS7?

 

i believe it is a 90mm also

 

I've heard anywhere from 750 to 780 so, someone take one and see how much it will.

 

Dead thread reborn... but here is the info I found:
in factory format (no porting or filling) we flowed:
the 1996-2004 4.3/5.0/5.7/7.4L (vortec) @ 780cfm
the 1999-2002 4.8/5.3/6.0L (cable version) @ 759cfm
the 2001-2002 8.1L (fly-by-wire) @ 795cfm
the 2003-2004 4.8/5.3/6.0/8.1L (fly-by-wire) @ 792cfm
the 1998-2002 5.7L (f-body cable version) @ 766cfm
the 1999-2002 5.7L (y-body fly-by-wire) @ 790cfm
the 2003-2004 5.7L (y-body fly-by-wire) @ 800cfm
all tested on a SF-1020 Flow-bench @ 28" H2O
*note* all versions with an idle air control couldnt break over 780cfm
a 496 (8.1) @ 6000rpm requires 870cfm air-flow @ 4" hg @ sea level
a 350 (5.7) @ 7000rpm requires 725cfm air-flow @ 4" hg @ sea level