More WOT AFR stuff

[timsiford at hushmail.com]

Went back through some old diacom readings last night.  

With the stock chip on my '90 IROC (730) with heads/cam and upgraded stock 
TPI intake I was hitting AFRs of 11.7@ 4200rpms.  After installing the MiniRam 
and adjusting the WOT AFR vs RPM table Diacom is showing that I am hitting 
AFRs of 11.2 @ 5500rpms.  So, even though I calculated a 10.2 AFR Diacom 
is reporting an 11.2 AFR.  I think that Diacom is correct on this one but 
it is only a hunch.  This is refreshing information for me :-)

Tim

At Thu, 16 Nov 2000 17:46:00 -0500, rr <RRauscher at nni.com> wrote:

>
>
>Umm, I just checked the anht hac, and I can't get the equation quoted
>below to give me the same answers as the code.
>
>Using tables L860D & L8617 @ 80c & 6400rpm, I get an AFR of
>11.6:1. Here is the equation using the raw bin values:
>
>WOT AFR = 6553.6 / ((TBL L8617 + TBL L860D + 128) * 445) / 256)
>
>w/vals:
>
>11.6 = 6553.6 / ((138 + 58 + 128) * 445) / 256)
>
>This is right from the hac and matches the code (I corrected the one 
>table
>address in the equation). What are the AFR's when using this equation?
>
>Thanks,
>
>BobR.
>
>
>JN wrote:
>
>> Wow, in looking at my bin that was modified by a reputable tuner originally,
>> he has what I calc as a 14.12 AFR at 5200 and a 14.85 at 5600!  I 
>guess with
>> the miniram I should fatten these up some.  Tim, what do you have 
>for PE vs
>> RPM.  Our motors are similar cams, intake and we both run 30 pound 
>injectors
>> with a 33 pound injector constant.
>>
>> Jason
>> ----- Original Message -----
>> From: <timsiford at hushmail.com>
>> To: <gmecm at diy-efi.org>
>> Sent: Wednesday, November 15, 2000 4:04 PM
>> Subject: Re: Question about WOT table in $8D bin
>>
>> > Bruce,
>> >
>> > I don't think its as bad as what you are saying.  Please - hear 
>me out.
>> >  I said that the calculation shows that I am running 10.16 AFR. 
> This was
>> > at 5600rpms and a coolant temp of 80deg C.  HOWEVER, the stock AUJP 
>bin
>> > has a PE modifier of 7.8 at 4000rpms in WOT %Change in AFR vs RPM 
>and a
>> > modifier of 22.7 in WOT %Change in AFR vs Coolant.  This results 
>in a
>> 10.22
>> > AFR.
>> >
>> > Now, I am NOT running 10.16 everywhere.  I just picked the highest 
>point
>> > of the curve and reported that point.  I also picked the highest 
>point of
>> > the AUJP curve and reported that.  Again, the formula I am using 
>is the
>> > one previously supplied here on the list ....
>> >
>> > ( 1  -  (( RPM Mod  +  Coolant Mod )  /  100 )  *  14.7
>> >
>> > I am not concerned about the fueling.  I am close to 128 at all 
>points
>> when
>> > driving.  I spent significant time on the VE curves.  The WOT %Change 
>to
>> > AFR tables are modified from stock ... but, no so much in the levels 
>but
>> > more as to the shape.  The MiniRam doesn't need as much fuel at 
>4000RPMs
>> > as compared to the TPI.  However, it does need more at 5600rpms.
>> >
>> > Tim
>> >
>> > At Wed, 15 Nov 2000 12:28:20 -0500, "Bruce Plecan" <nacelp at bright.net>
>> wrote:
>> >
>> > >
>> > >
>> > >IMO,
>> > >Your running a diesel now.
>> > >You have enough fuel that your CR is even up.
>> > >At tear down the ring lands will be knocked out and you'll need 
>pistons.
>> > >Just about beat you have a 160d and within one heat range of stock 
>plugs.
>> > >The tip of the plug is acting like a glow plug for lighting the 
>change.
>> > >It kinda a typical thing when your at more fuel more timing agenda 
>stuff,
>> > >just some guys go that route wastes gas, and tough on parts IMO.
>> > >No telling what the heads will be like, if (oem) iron probably 
>cracked
>> > >between the seats.
>> > >Also, will have more carbon to deal with and more likely to burn 
>an
>> > >exhuast
>> > >valve.
>> > >It's like doing a nitro tune but with gas, eats parts
>> > >Bruce
>> > >
>> > >
>> > >> >Just remember you said that <g>
>> > >>
>> > >> I'll remember Bruce <g>.  But, I'm not a fluke.  I've talked 
>to several
>> > >> other AFR190/MiniRam ownders that are running the same type of 
>spark
>> > >advance
>> > >> (max).  Now sure about the Air/Fuel ratio they are running though.
>> > > Will
>> > >> be pulling plugs soon to take a gander.
>> > >>
>> > >> Curious though .... I have a feeling that you think I'm gonna 
>blow
>> > >myself
>> > >> up :-)  Can I pick your mind and ask why?  I know that I will
>> eventually
>> > >> lose the bottom end ... but, I don't think that it will be PROM
>> related.
>> > >>
>> > >> Tim
>
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