It was way too low for my liking. But, let's not forget that this was MINNESOTA GAS! It was 92 octane BP pump premium, with a minimum 10% ethanol content. Ethanol needs to burn at richer mixtures, because the fuel contains oxygen. So, the optimum power mixture of 12.5:1 for A/F does not apply to this fuel. As a result, a lower A/F is expected.
When I was originally tuning this engine with the PI intake, we started with 77 jets, and worked our way all the way down to 67 jets. We had peaked in power with the 70 jets, but when we changed to the 67 jets, HP went down, even though the A/F was up to 12.8:1. On the dyno, you always jet for power, because it automatically removes other variables (like ethanol in the fuel). So, during the testing I was more interested in seeing that the A/F was stable from manifold to manifold, rather than looking at the absolute A/F numbers.
And here I was hoping you would sell me all your dual plane intakes for cheap LOL! I think you are wise to hang onto them, because the next test could come out completely differently. We will see...
Jay Brown
1968 Shelby GT 500 Convertible, all aluminum 489" 1030 HP Supercharged FE
1969 XL Convertible, 460
1969 R code Mach 1, 706 HP 511" all aluminum FE, 10.457 @ 127.47, 2005 Drag Week Winner, Naturally Aspirated Big Block
