[Gmecm] Re: Fuel Economy

[Mark Romans]

No No No!   You can't run a wide band in place of a narrow band.
The Wide band puts out a somewhat linear 0-5 v output.
The narrow band puts out a non-linear 0-1 v output.
I was datalogging with diacom with one pc and the wide band
with a 2nd pc, datalogging the wideband afr, lamda, rpm and tps.
Then going back and looking through each datalog and comparing screens to 
set the afr's.
Mark
----- Original Message ----- 
From: "Darrell" <ndarrell at telusplanet.net>
To: <gmecm at diy-efi.org>
Sent: Thursday, September 15, 2005 9:08 PM
Subject: Re: [Gmecm] Re: Fuel Economy


> Cowen: (and all)
> 
> Well, you are right, second times the charm.  Thank you for 
> responding anyway, and getting a little action going on the thread.  
> A lot of this information will be useful, thanks to all who posted on 
> the topic.  Some of it went way over my head, but I'm here to learn.
> 
> Interesting idea about using a WBO2 sensor, has anyone actually tried 
> this?  I mean replacing a stock NB with a WB on a stock computer?  
> That in combination with changing the voltage threshold may allow you 
> to set the AFR to a slightly leaner mixture overall.
> 
> I was thinking more of optimizing the ignition advance, perhaps 
> advancing the timing a bit on light throttle acceleration, tweaking 
> the deceleration enleanment up a bit, that sort of thing.
> 
> Definitely the low restriction exhaust system will help, I used to 
> drive a Camaro with cheap turbo mufflers, when the mufflers blew out 
> my gas mileage went up by 10%!   Also thinking about 1.6:1 rockers 
> for the exhaust valves to increase the flow a little.
> 
> Not sure what I can do on the intake side, haven't really researched 
> what's available for that engine, but I suspect not much.  Perhaps 
> some 3.1l parts, I've heard that 3.1l heads make a fairly big 
> difference.  A straighter intake tube with smooth sides rather than 
> the ribbed stock hose may help as well, and perhaps a larger diameter 
> MAF.  I'd actually like to get rid of the MAF altogether.
> 
> I tend to agree with Bruce's observation, if you make more power, you 
> need to get into the throttle less for the same effect, and fuel 
> economy is tied to engine RPM and throttle position...  That is, if 
> you can resist the temptation to put your foot in it.
> 
> On 15 Sep 2005 at 16:33, Cowen wrote:
> 
>> Wow!  A bit of vigorous action on this topic!  This IS
>> my first rodeo, at least in this arena, and normally I
>> might not have responded to Darrell, but it seemed no
>> one else was, so I gave it a whirl.  I thought I put
>> in enough "maybes" to draw out some clarification from
>> the experts...  Well! I have been severely chastised
>> for some poor writing skills!
>> 
>> GAS said:
>> > NB more sensitive at what ratio?  On what WB sites
>> > are you referring
>> > to?  
>> 
>> Not "NB more sensitive" at some other ratio, I
>> understand NB to be very limited.  I meant to suggest
>> that WB might allow closed loop with leaner AF ratios
>> than stoich, which would be a probable benefit because
>> although stoich is chemically the best ratio, "best"
>> ratios vary depending on your needs, for power,
>> emmissions, economy, driveability, etc...(hence PE
>> mode).
>> 
>> What sites?  I have to admit, I've only skimmed some
>> of the WB sites found in a Google search, I don't have
>> any suggestions for which is most detailed...  But
>> don't worry, none of them I saw are trying to use NB
>> sensors outside stoich!
>> 
>> Gas also said:
>> >The NB sensor is a switch centering around, and
>> > being most
>> > sensitive at stoich.  It's sensitivity deteriorates
>> > the farther from stoich
>> > (either direction) the AFR.  There are NB O2 sensor
>> > voltage to AFR
>> > curve charts on the net, that verify this.  By
>> > design, NB sensors need
>> > not be accurate at AFRs away from stoichiometric.
>> 
>> Thanks for clarifying and expanding on exactly what
>> I'd said about NB O2 sensors!
>> 
>> GAS continued:
>> >  There is WB O2
>> > sensor technology
>> > however, that allows for PCM closed loop operation
>> > at ratios leaner
>> > (or richer) than stoich.
>> > 
>> > GAS
>> 
>> Again, my case stated more eloquently. Now I know why
>> no one else responded to Darrell! :)
>>  
>> 
>> 
>> **********************END TRANSMISSION**********************
>> 
>> 
>> 
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