wideband datalog of my NA
03-22-07, 09:20 PM
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wideband datalog of my NA
i did this last fall before i put the car into storage. i wanted to post it up just to show my datalog (might be of interest to people), and see if anyone has any tuning tips.
but it's kind of moot for me. i have a Megasquirt sitting in my room waiting to go in, and hopefully i will have better luck tuning that. my problem with the stock ECU+SAFCII is that i could never dial in the AFR very well. this datalog was about as consistent as i could get it. i aimed for a 12.5 AFR at WOT, because without a dyno i can't really tell what is absolute best (there is also environmental conditions to take into account). also i don't think airflow correction is the most accurate way to tune something. that's just what i think though, hopefully something else isn't the cause of AFR irregularity.
anyways, this is a graph of a 1st and 2nd gear (and a bit of 3rd) pull datalogged using a Zeitronix ZT-2 wideband. i hope it isn't too hard to read. this was street tuning on a bit of an uphill to put as much load on the engine as possible. unfortunately i was short shifting a bit because i was reading 8k on the tach which read 500rpm too high. ah well...
oh, this is just a stockport S4 engine. i'm seeing what i can get from it before it kicks (which will probably not happen anytime soon). click on my sig for mod list...
but it's kind of moot for me. i have a Megasquirt sitting in my room waiting to go in, and hopefully i will have better luck tuning that. my problem with the stock ECU+SAFCII is that i could never dial in the AFR very well. this datalog was about as consistent as i could get it. i aimed for a 12.5 AFR at WOT, because without a dyno i can't really tell what is absolute best (there is also environmental conditions to take into account). also i don't think airflow correction is the most accurate way to tune something. that's just what i think though, hopefully something else isn't the cause of AFR irregularity.
anyways, this is a graph of a 1st and 2nd gear (and a bit of 3rd) pull datalogged using a Zeitronix ZT-2 wideband. i hope it isn't too hard to read. this was street tuning on a bit of an uphill to put as much load on the engine as possible. unfortunately i was short shifting a bit because i was reading 8k on the tach which read 500rpm too high. ah well...
oh, this is just a stockport S4 engine. i'm seeing what i can get from it before it kicks (which will probably not happen anytime soon). click on my sig for mod list...
03-23-07, 03:12 AM
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what areas are you referring to? the AFR will go very lean if there is low or no throttle. actually there is essentially no fuel if you have 0% throttle.
i have cruise, less than 25% throttle or so, tuned very lean, about 16 AFR at steady cruise (i.e on the highway).
the full-throttle parts of the graph are (approximately on the y-axis which is TIME for all graphs):
1st gear: 22:47:00-22:47:02
2nd gear: 22:47:03-22:47:08
3rd gear: 22:47:09-22:47:15
i tried to tune these parts between 12.5-13.0 AFR, but as you can see it's not very smooth.
i have cruise, less than 25% throttle or so, tuned very lean, about 16 AFR at steady cruise (i.e on the highway).
the full-throttle parts of the graph are (approximately on the y-axis which is TIME for all graphs):
1st gear: 22:47:00-22:47:02
2nd gear: 22:47:03-22:47:08
3rd gear: 22:47:09-22:47:15
i tried to tune these parts between 12.5-13.0 AFR, but as you can see it's not very smooth.
