AFR to Mv conversion?
Thread Starter
Restricted User
iTrader: (9)
Joined: Sep 2002
Posts: 7,603
Likes: 0
From: Sierra Vista, AZ
AFR to Mv conversion? Whats a conversion table for takign your O2mv readings and making them into AFR?
I seen CAL had a reply earlier that a 890mv = 12.8:1
I am seeing 940mvB1S1, and 950mv B2S1?
Would like to tune it out to around 12.9-13.1:1 AFR! Thanks.
I seen CAL had a reply earlier that a 890mv = 12.8:1
I am seeing 940mvB1S1, and 950mv B2S1?
Would like to tune it out to around 12.9-13.1:1 AFR! Thanks.
Thread Starter
Restricted User
iTrader: (9)
Joined: Sep 2002
Posts: 7,603
Likes: 0
From: Sierra Vista, AZ
Re: AFR to Mv conversion? Logged a little,
Part throttle various % position,
LTFT's B1 & B2 -6.xx to -2.xx, nomore than 1.5x between them except when blipping throttle, B2 goes negative more on decl, but then levels out to match B1.
WOT, LTFT's B1 = 0.00 B2 = -0.78 to 0.00
O2's B1 = 930
B2 = 935
No timing issues, and No KR thoughout the Band.
Are the LTFT's in good range, and how do you correct them if needed?
Not sure what the AFR is using the O2's (not WB O2 yet) But figure if 890mv is 12.8:1 then I must be running rich?
Part throttle various % position,
LTFT's B1 & B2 -6.xx to -2.xx, nomore than 1.5x between them except when blipping throttle, B2 goes negative more on decl, but then levels out to match B1.
WOT, LTFT's B1 = 0.00 B2 = -0.78 to 0.00
O2's B1 = 930
B2 = 935
No timing issues, and No KR thoughout the Band.
Are the LTFT's in good range, and how do you correct them if needed?
Not sure what the AFR is using the O2's (not WB O2 yet) But figure if 890mv is 12.8:1 then I must be running rich?
Re: AFR to Mv conversion? There is a lot of variation in the A/F to O2 mV
transfer function. Look at these charts:
http://community.webshots.com/album/74289894mbMeMp
If you know roughly what your exhaust gas temp is,
at the sensor, then you could interpolate from
there. But few people have that good a setup.
12.8 is "rich". But, there's rich relative to
stoichiometric ideal (12.8 is) and there's rich
relative to peak power mixture (12.8 is about
right for that). Give or take a couple of ticks,
the best bet is just to get peaked up on your
best guess until you have higher-quality
measurement.
If you do get on wideband and have someone tune
it for best HP/TQ, post up the wideband best A/F
ratio number and your corresponding in-car O2s.
transfer function. Look at these charts:
http://community.webshots.com/album/74289894mbMeMp
If you know roughly what your exhaust gas temp is,
at the sensor, then you could interpolate from
there. But few people have that good a setup.
12.8 is "rich". But, there's rich relative to
stoichiometric ideal (12.8 is) and there's rich
relative to peak power mixture (12.8 is about
right for that). Give or take a couple of ticks,
the best bet is just to get peaked up on your
best guess until you have higher-quality
measurement.
If you do get on wideband and have someone tune
it for best HP/TQ, post up the wideband best A/F
ratio number and your corresponding in-car O2s.
02, 128, 890mv, afr, automotive, calculator, chart, conversion, gm, millivolt, millivolts, mv, o2, o2mv, stoichiometry, table, tuning, vs
