How is the target PE AFR actually calculated for 95 Camaro LT1 $EE in TunerPro.
I've got 3 different versions and none seem to match up
Thanks
Mitch
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How is the target PE AFR actually calculated for 95 Camaro LT1 $EE in TunerPro.
I've got 3 different versions and none seem to match up
Thanks
Mitch
It is compicated.
Here is the formula
$FFFF*($93/($80+PEvsRPM+PEvsCOOLANT))=$XXYY
[$XX]/10=PEAFR
It is all in hex, so you need a hex calculator.
The XX result is converted to decimal and divided by 10 and you got PE target at given Rpm and temp.
in my eex xdf, i wrote:
is this not reasonably accurate? always seemed pretty good to me. also tunercat has similar documentation.Code:AFR = PE AFR Base (usually 14.7:1) / ( BOTH PE TABLES ADDED - 1)
Thanks steveo, just wanted confirmation. I've got a slightly different info from t'internet.Quote:
Originally Posted by steveo
Kur4o: Concise answer but a little deeper than i required.
OK Bought a milling machine to cut the manifold. Done that. Initial test looks like the split on BLM's changed sides... but they still swap around.
My AFR guage doesn't match BLM's. idles around 15-16 AFR. BLM's at 120-130 . LO2 sits at 750mV for 7 mins the other sits around 4mV. New O2's to go in. PE showing around 16-18 .
Thanks
Mitch
widebands and narrowbands definitely dont read the same at very low airflows
probably because there is a ton of flutter, and their response rates are very different
id actually trust trims more than wideband at idle
Replaced the 02's & knock sensor again just for fun.Quote:
Originally Posted by steveo
AFR Guage matches the O2's but output appears different when read by EEHack....
Idle: BLM's 119_128... AFR 14.5-15 EEHack is showing 17.0
PE O2's read 850-880mV EEHack is showing 14.7
Wideband reads 22.39 at power on & 7.45 until car fires up. Pretty close to full range.
I did recalibrate the LC2 Wideband a few months ago but need to check output settings. Steveo mentioned narrowing the range but i'm pretty certain i didn't alter it from the std 0-5V output.
Steveo: Can i see the actual value of the AC Pressure anywhere?
Any suggestions.
Thanks
Mitch
for sure, and more!Quote:
Steveo: Can i see the actual value of the AC Pressure anywhere?
the full blown parameter selector is accessible in two places, in the graphing window, or in the user parameter section of the datalog window (bottom right). the datalog window is restricted to msg0 parameters (the main message) only. the graphing window, however, can graph anything.
choose view level 'extended' to get anything useful
to save time, simply type 'ac' in the search box
see attached screenshot
this is due to the lack of linearity of the 0-5v inputs on the ecm.Quote:
Wideband reads 22.39 at power on & 7.45 until car fires up. Pretty close to full range.
I did recalibrate the LC2 Wideband a few months ago but need to check output settings. Steveo mentioned narrowing the range but i'm pretty certain i didn't alter it from the std 0-5V output.
it'll never be 100% accurate, but the error is more dramatic if you're trying to get a huge range of afr values.
to get reasonable accuracy, i'd reccommend reconfiguring your wideband to read a narrower range, 0-5v=9.0:1-16:1 or something like that. that way the tiny bit of curvature wont have much effect.
I know you've mentioned that before but i hadn't realised how much the input was skewed.Quote:
Originally Posted by steveo
The input voltage swings from 5.00V to 0.02V when the car starts, so the LC-2 does output the full range of voltage.
Excellent.
Thankyou.
Mitch
the 0-5v is always ok, it's more that if you graphed input voltage vs logged voltage, it has a bit of a curve to it.
if we could get a proper graph i could make a compensation table, but robert once stated that it varies depending on the current of the particular wideband, so i never got around to it.
with my logging i usually found it was off by less than 0.1 afr, which is about as accurate as a wideband is anyway... but with a default 10-20 afr or whatever, it gets a bit sketchy