Annular boosters on a Tunnel Ram
With a bigger MAB, there's more air flow so it pulls more fuel. Not difficult to grasp.
How much MORE air flow is there at idle and low engine speeds and what does that do to the pressure drop across the booster?
Thats what Taylor is saying. At low air flows the pressure differential makes the MAB act like an emulsion. The signal is now weaker and the MAB start is DELAYED.
You have to think in terms of air flow and pressure differential across the booster and the bowl vent.
When you think about that, it becomes clear what Taylor is saying.
Plus, if you can do algebra you can mathematically calculate it out.
Thats in the Taylor books and Oberts “Internal Combustion Engines” and I think “The Design and Tuning of Competition Engines” by Phillip Smith.
You can’t just read one quick quote like I posted above. But I can tell you 100% that Tuner says this is true and Shrinker says it’s true and my testing says its true.
Air flow changes the pressure differential across the booster and that changes the way the MAB acts.
You can also find this is NACA (I think it’s now NASA) Report 49 and also in Effects of Air-Bleed Systems on Carburettor (sic) Performance by Yasuke Asano, Toshitska Chuma, Heiichiro Haga and Tadahiro Mochida.
I can‘t remember where the latter came from so if you can’t find it, PM me your email and I’ll have the wife scan it and email you a copy.
