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Old 08-21-2013, 06:17 PM   #1
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Default AFR/Timing/Fueling question

Hey guys, I want to start focusing on fixing my fuel map (it's pretty ugly right now) and was hoping folks could look at my AFR target and Timing maps so I know they're right before I start adjusting fueling. From what I'm hearing on fueling it should be going up in a linear fashion, however I don't want to play with the fuel map until I'm sure everything else is OK. I attached my fuel map for kicks if anyone wants to advise me on this. I'd like to avoid going to a Dyno this time, I'm tired of paying for peak power and having shitty cruising fuel economy.
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AFR/Timing/Fueling question-fuel-map.png  
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File Type: csv 8-21-2013 - AFR table.csv (4.1 KB, 71 views)
File Type: csv 8-21-2013 - Fuel table.csv (6.3 KB, 61 views)
File Type: csv 8-21-2013 - Timing table.csv (5.3 KB, 70 views)
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Old 08-21-2013, 10:42 PM   #2
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So, there's no VEA or VEAL for a Hydra?

Your AFR table doesn't make sense to me. Some areas have sensible values like 12:1 and 14:1. Other areas have gibberish like 0.5:1 and 43:1. What's up with that?

Do a search for AFR tables. There are threads with good examples along with discussion of why you use certain AFR's in certain operating areas.
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Old 08-22-2013, 03:38 PM   #3
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Oh shoot yeah the AFR table and Timing table CSVs are backwards (AFR table is the timing table, and vice versa). I tried using interpolation to clean up my fuel map, but it gutted some sections so deeply that they would likely have very lean cells.
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Old 08-30-2013, 02:46 PM   #4
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Bump. Anyone?
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Old 08-30-2013, 05:44 PM   #5
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I don't run that lean at idle, but run leaner in cruise(15.5-16), and I think you can run leaner in your under 8 psi boosted cells(~12.2-12.7). I didn't look at anything else yet because I'm driving.
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Old 09-04-2013, 05:18 PM   #6
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I have trouble idling smoothly at 900rpm and anything more than ~14.7, but anything 1250+ and in a vacuum cell was adjusted leaner (target of 15.6, might bump it up even more), as was boost up to 6psi (target of 12.2:1, 7psi has 12:1 and 8 has 11.8:1).

Car runs surprisingly well in cruise for running so lean, just need to go through a tank without any ignition issues and I should have some improved economy. My last mostly freeway tank I got 22mpg, if I can get 24 I'll be happy. If I break 26 (doubtful) I'll be back to the worst mpg tank I had prior to converting to turbo.
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Old 09-04-2013, 05:49 PM   #7
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Some of the economy might be from your timing too. Joe has a good thread where he adjusted his timing in the cruising cells for fuel efficiency. Basically, the closer you are to MBT the better economy you will get (which makes sense, a more complete burn, more torque).

IIRC he was datalogging pulsewidth to help him determine if a change resulted in better or worse economy.
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