CLASS RACER FORUM - View Single Post

Paul Merolla · 08-03-2012, 02:34 PM

In my opinion, yes it will. That formula doesn't take into account the fact that when the carb is flowing its "rated" cfm, it is causing a restriction and vacuum is increasing. Bigger carb = less restriction = more power...to a point. Too big and you'll lose signal. My street car is almost identical to the way you've described your customer's ride. When I started taking it to the Friday night street drags, it had an Edelbrock 600 cfm on a Performer RPM intake. It ran fairly consistent 12.90s every week. For an experiment, one Friday I bolted my buddy's 850 Holley on. The new norm became 12.80, then after lots of jet changes and squirter changes, the car ran a best of 12.63. I thought that was cool, but he wanted his carb back so I bought a 750 DP almost new and spent week after week chasing that elusive 12.63 to no avail. It settled in at .70s and that was it. Sorry for the long story...but my logic tells me the bigger the better (within reason of course), as long as you can keep the A/F where it needs to be.

08-03-2012, 02:34 PM	#2
Paul Merolla Senior Member Join Date: Dec 2001 Location: Papillion, NE Posts: 610 Likes: 242 Liked 293 Times in 65 Posts	Re: Holley carburetor question In my opinion, yes it will. That formula doesn't take into account the fact that when the carb is flowing its "rated" cfm, it is causing a restriction and vacuum is increasing. Bigger carb = less restriction = more power...to a point. Too big and you'll lose signal. My street car is almost identical to the way you've described your customer's ride. When I started taking it to the Friday night street drags, it had an Edelbrock 600 cfm on a Performer RPM intake. It ran fairly consistent 12.90s every week. For an experiment, one Friday I bolted my buddy's 850 Holley on. The new norm became 12.80, then after lots of jet changes and squirter changes, the car ran a best of 12.63. I thought that was cool, but he wanted his carb back so I bought a 750 DP almost new and spent week after week chasing that elusive 12.63 to no avail. It settled in at .70s and that was it. Sorry for the long story...but my logic tells me the bigger the better (within reason of course), as long as you can keep the A/F where it needs to be.