[Gmecm] Adjusting 7730/$8D for larger cam

[Mark Romans]

Every time you make a change, save the file with a new name and keep a log 
of what was changed on each file.
That way in case you have undesired consequences you can always go back to a 
known good one.
Mark

----- Original Message ----- 
From: "Clair Davis" <clair.davis at charter.net>
To: <gmecm at diy-efi.org>
Sent: Friday, February 02, 2007 8:43 PM
Subject: Re: [Gmecm] Adjusting 7730/$8D for larger cam


> John,
> Question regarding the O2 constants you mentioned...
>
> In the Constants/Scalars section, I've got:
> 0.60V at 496 (Idle O2 Rich/Lean Threshold Fast)
> 0.60V at 497 (Idle O2 Rich/Lean Slow Zero Error Upper)
> 0.56V at 498 (Idle O2 Rich/Lean Slow Zero Error Lower)
>
> Are you saying to knock them all down by 0.04 - to 0.54, 0.54, and 0.52? 
> I
> haven't done that yet, but I can before I burn again.  I bumped the idle
> spark advance at 800rpm up to 24.96* from 20.04* in the Closed Throttle 
> vs.
> RPM table.  That's the same as the 1200rpm point, not a big bump, and this
> engine likes idle advance.
>
> With some luck, I'll get to try this out tomorrow, and see what the BLM's
> look like as well.
>
> On a semi-related note, what are some thoughts on saving versions of bins 
> to
> help track progress?  I've got very few changes at this point, so I've 
> been
> keeping essentially a single file so far.  I can see how I'll need 
> multiple
> files in the very near future, and I'd like to keep up with what has been
> changed.  I'm thinking date-stamp-type file names, but that can get
> ungainly, and the XDF would have to be changed at the same time.  Maybe no
> biggie, if I keep the date stamp in a directory name.  There must be some
> tidier ways, though.
>
> Thanks again,
>
> Clair
>
> ----- Original Message ----- 
> From: "JohnsHome" <JohnsHome at wideopenwest.com>
> To: <gmecm at diy-efi.org>
> Sent: Thursday, February 01, 2007 9:32 PM
> Subject: RE: [Gmecm] Adjusting 7730/$8D for larger cam
>
>
>> I would suggest upping your idle timing a bit to see if that helps.
> (closed
>> throttle table L81FD-8209)
>> Removing about 40mV from the o2 constants may help as well.
>> They are at L8496 thru L8498 locations. Will get the smell of unburnt 
>> fuel
>> to get better as well.
>> Not knowing what cam you are running, although it sounds like its mid 220
>> range from the description I'm not sure what else to suggest. Hopefully
> you
>> are running a heated o2. If not, get one for sure.
>> Idle will probably need to be around 700-800 rpm.
>> There is a hard code idle limiter in AUJP if that is what you are 
>> running.
>> It can be increased by changing BOTH values to be the same at locations
>> L426C & L4270.
>> these are in the code and will need to be added to your XDF or just done
> in
>> the hex editor.
>> They are single byte, RPM = 6400/255 = 25 rpm increments.
>> For 1000 RPM max idle you would use a value of $50
>> These have helped me out with my 224/230 roller 350. My idle is at 58Kpa 
>> @
>> 800 RPM.
>> HTH
>> John
>>
>
>
> _______________________________________________
> Gmecm mailing list
> Gmecm at diy-efi.org
> Subscribe: http://lists.diy-efi.org/mailman/listinfo/gmecm
> Main WWW page: http://www.diy-efi.org/gmecm
>