Is it still safe to say that a 650 Speed Demon is comparable to a 750 Holley/QFT?
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The demon is supposed to be good for about 400 hp. Me, Larry, and George have then and the cars run great
Is Demon still rating there carbs using wet flow vs Dry flow the others use? I've read in other posts from a few years back that a Speed Demon 650cfm with annular boosters is the equivalent of a holley 750cfm. I've already got the Cobrajet cam and the BT intake on back order so 400 hp might be setting the bar low with a 650 carb. Unlikely I'll be running at 6500 rpm for very long on the street but would like to get the most out of a 357 iron head 4V cc set-up
I think Demon stopped the wet flow rating practice on some if not all of their carbs. It certainly caused confusion.
A Holley 750 has 1-11/16" throttle blades and 1-3/8" venturi throats, the Demon you select should have the same size throttle blades and venturi throats. Keep in mind that the big annular boosters reduce air flow a small amount. The trade-off is better low rpm performance, better fuel atomization at all rpm, therefore better fuel distribution within the intake manifold.
I believe I checked this before I made the recommendation for the 750 Demon, but it doesn't hurt to double check my work. My memory is really bad nowadays. Also keep in mind Demon Carbs has changed their product line a bit since they were bought out. If I've made an error please let me know. There is no reason for concern, a 750 carb is not too big, especially if it has annular boosters.
A Holley 750 has 1-11/16" throttle blades and 1-3/8" venturi throats, the Demon you select should have the same size throttle blades and venturi throats. Keep in mind that the big annular boosters reduce air flow a small amount. The trade-off is better low rpm performance, better fuel atomization at all rpm, therefore better fuel distribution within the intake manifold.
I believe I checked this before I made the recommendation for the 750 Demon, but it doesn't hurt to double check my work. My memory is really bad nowadays. Also keep in mind Demon Carbs has changed their product line a bit since they were bought out. If I've made an error please let me know. There is no reason for concern, a 750 carb is not too big, especially if it has annular boosters.