more 747 questions

[steve ravet]

Bruce Plecan wrote:
> 
> From: steve ravet <steve at sun4c409.imes.com>
> Subject: Re: more 747 questions
> 
> >> Your looking at two different tables, one is an enrichment (a fuel
> >> VE addition), and the other a final air fuel ratio.  The 0487-048E
> >> would be expressed after the conversion as something like 12.5:1,
> >> the other as a percent.  The percentage is added as PE is enabled.
> >
> >But, at WOT you are open loop, right?
> 
> Open loop just means it's not looking at the O2 voltage at that moment.
> There are still BL corrections applied, coolant temp
> corrections applied.  The Injectors have to have enough capacity for
> accleration modes.  So control of WOT AFR is nececessary,
> and the fuel reguirements may or maynot be linear.

I'm still confused.  This table lists desired A/F ratios, right?  But at
WOT you're not measuring A/F because you're ignoring the O2 sensor. 
Having a table of A/F values seems to imply closed loop operation in
that you measure A/F, compare to what's in the table, and adjust if
necessary.

--steve




--
Steve Ravet
International Meta Systems
http://www.imes.com
steve at imes.com