[W126 Coupe] optimum air to fuel ratio

[Dan Landiss]

Shayegan, Richard wrote:

>There's more fuel but less air right?
>
Nope, more fuel SAME air.

>I know leaner = more power for
>2-strokes
>
Don't bet on it.

>, I know in Indy the driver's lean em out as far as they can
>(I've even seen a blown engine on the last lap as the driver tried to
>lean it out further to get more power)
>
He was leaning it out to try to get to the finish on an empty tank.

>, and a guy I know who builds race
>cars says leaner=more power
>
Does he also sell bridges?

>, but then everywhere I read says 13.5 is
>ideal for power. Is it just that 14.7 is overlean?
>  
>
14.72 = theoretical perfect ratio, fuel exactly combined with oxygen
15.5 = best economy
12.4 to 13.2 = best power

(Reference: MoTeC Air Fuel ratio Meter Manual, 
<http://www.motec.com/support/manuals/Manual%20AFM1%20A5.pdf>



>Here's an example of the conflicting evidence
>http://www.kennebell.net/faq/faq-answers11%286%29.htm
>
>It says in answer to the third question 13.5 is ideal for power, but it
>takes high octane to run lean.
>
Problem with that statement is that 13.5 is rich, not lean.

> Then it says want more power run higher
>octane and go leaner (I'm paraphrasing). This is a link Jim Nowak gave
>as evidence that 13.5 is better than 14.7, so it makes me think it's
>credible.
>  
>
13.5 is richer, not leaner. That is an air/fuel ratio, as you add fuel 
the ratio gets smaller because fuel is the denominator.

--
Never argue with a dragon, for you are crunchy and taste good with ketchup.