[Tom Vaught]

Today, going to talk a bit about Carb Tuning to match the airflow going into a specific Carb Bonnet.

The HO Racing Guys had a nice Bonnet Design for their Q-Jet Carb but the bonnet was heavy.

Heavy is not all bad, as I have seen thin wall Bonnets split apart under Higher Boost Conditions and people always get greedy when it comes to Boost Pressure.

Step 1: Whoa, 15 psi, scared myself and soiled my shorts.
Step 2: Ok, 15 psi is fun, but I think I will try 20 psi. OOPS, time to change underware again.

Step 3: Well, I am up to 38 PSI on the boost, making over 800 HP with my 4 cylinder 200 cid Pontiac Engine and maybe I ought to fix the drivability of the vehicle off boost and make it more fun to drive vs scare the crap out of myself.

Drive-ability is based on getting the air/fuel right at all of the load/rpm points and having a smooth transition between each of those points.
You can do it with a NA Holley carb and you can do it with a Boosted Holley carb, if you get the air distribution right so that the carb boosters are happy and all of the cylinders are making the same basic power per cylinder.

PROPER Air Distribution really helps in that area when using a carb system and boost.

With EFI you can tune each cylinder based on uneven air distribution and still get away with it.
Much harder with a boosted carb engine because now you have to look at the air distribution as a Systems Approach:

How does the air come into the Bonnet?
How does the air mass divide between the given Carb Boosters?
How does the Intake Manifold design distribute that air mass to the cylinders?

More on this later this afternoon.

Tom V.