750 Holley but flows 930CFM???????

[72Dart360]

I've heard this a few times and decided to ask the question. How do you change the CFM in a carb? I've seen this in magazines and read a thread on this site that someone had a holley 750 but flows much more, how??

 

[george]

I wont post tech responses to the board anymore, but if you are interested, I can pm you.

 

[Snake]

One way to increase cfm is to remove the choke plate it alows more air to flow freely into the throat.i do this on all of my holleys.

 

[dgc333]

Air flow is a function of the pressure drop across the carb. So you can remove restrictions (ie. remove the choke plate, smooth the inlet, etc) while testing at the same pressure drop or simply test it at a higher pressure drop. 4bbls are typically rated at 1.5" Hg pressure drop but if you increase the pressure drop you increase the flow. That would be deceitful if someone was advertising a carb that is a 750 size with 930 cfm rating by testing at a higher pressure drop.