750 Brawler vs 650 AVS 2 at the track, right OOTB !

What does all that do exactly?

The correct boosters atomize the fuel more with less of a vacuum signal so it vaporizes at the right time instead of staying in liquid form during the power stroke.
Vacuum is generated all the way through the intake tract even at the intake valve. Last time I looked vacuum is what the piston generates as it travels down the bore pulling the air and fuel in does it not?

Correct except in an engine built for any level of performance it's actually the scavenging effect of the exhaust pulse creating the vacuum before the intake valve opens far more than the piston moving down the cylinder during the intake stroke. The key point is that air is a compressible fluid and has inertia so the vacuum created at the intake valve can easily be lost trying to travel to the carburetor or throttle body especially during WOT if the intake port and runner design is bad.
The average Hot Rodder isn't Darin Morgan with a wet flow bench to actually see what the wet flow is doing is he?

How do you crutch an engine with a SSR that causes fuel separation?


Here's a thought, If the engine needs more exhaust residual to heat the incoming charge to help vaporize it helping it burn better what happens?

No but he/she can apply the lessons in any engine even if it's not a Pro Stocker. This isn't something you need a wet flow bench to discover anyway, OEMs figured it out before that was popular all you need is a way to draw air through a port while injecting some kind of liquid with a dye. If the port isn't keeping the fuel atomized the liquid will show up as a dribble or stain running down the chamber walls.

You "crutch" a port that causes fuel separation by increasing restriction which absorbs flow energy (thus power) or like you said, add heat which also reduces power by decreasing the charge density. Get the port right and you make max power because those "crutches" aren't needed anymore.

Your example of the big Ford running better with the smaller carb is precisely an example of that, the port design was bad enough to where there was a net gain in power by increasing manifold vacuum at WOT because the intake charge quality was trash. If the intake ports and runners were corrected it would have made more power with a bigger carb.

Sorry to the OP for getting sucked into the shitstorm but I think this is useful info for everyone. It applies to his situation as well because if the engine has decent intake flow characteristics it will indeed benefit from having a properly-dialed 750 cfm DP carb over the 650 cfm AVS with the annular boosters. Booster types can be easily swapped in Holley-style carbs anyway. If the carb is "too big" for the application and more booster signal and fuel atomization is needed at lower RPM then converting to annular boosters fixes that issue better than going to a smaller carb because it's not creating an airflow restriction, at least not nearly as much.