Question about PLX wideband - help
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Oct 2003
Posts: 1,066
Likes: 1
From: Zurich - Switzerland
Question about PLX wideband - help Who is logging the AF ratio using the wideband output of the PLX M-300? (0-5 volts).
In my case the voltage doesn’t match with the display (about 0.2 volts too high).
This makes a difference of about 0.4 AF units (so according to the voltage I’m richer than the display).
What is your experience with this unit?
Should I trust the display or the voltage?
In my case the voltage doesn’t match with the display (about 0.2 volts too high).
This makes a difference of about 0.4 AF units (so according to the voltage I’m richer than the display).
What is your experience with this unit?
Should I trust the display or the voltage?
Originally Posted by pknowles
I see the same result. I trust the value I see in HPT, because when I dialed in my tune and my LTFT's went to 0, my AFR was 14.7 across almost all of the non-PE mode cells.
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Oct 2003
Posts: 1,066
Likes: 1
From: Zurich - Switzerland
I think the PLX is not so bad and it's not a problem to add a correction factor, the boring job is to find out the factor.
My real problem is that I go with the WB signal to the PCM through the A/C connector and read it using Atap.
Atap sees only one decimal, on top of this Atap (or the PCM) rounds up the values.
Example: 2.01 volts from the WB is logged as 2.1 V; but also 2.10 is logged as 2.1V.
The PLX formula is AF=(V*2)+10
0.1V is already 0.2 AF units, to my opinion a too big error. It would be better to go directly to the interface as EFILive (or maybe also HPTuners) and log the real numbers.
I made a test (pls don't call me stupid!): I recorded the display values and the RPM using a digital camers. Then watched the movie in slow motion to see what happens.
The display is refreshed about 8 times in a second (too fast to follow in real time) and I was able to draw a nice curve (excel).
Really time consuming but this would be a way to find out the correction factor, in fact PLX told me to trust the display...
My real problem is that I go with the WB signal to the PCM through the A/C connector and read it using Atap.
Atap sees only one decimal, on top of this Atap (or the PCM) rounds up the values.
Example: 2.01 volts from the WB is logged as 2.1 V; but also 2.10 is logged as 2.1V.
The PLX formula is AF=(V*2)+10
0.1V is already 0.2 AF units, to my opinion a too big error. It would be better to go directly to the interface as EFILive (or maybe also HPTuners) and log the real numbers.
I made a test (pls don't call me stupid!): I recorded the display values and the RPM using a digital camers. Then watched the movie in slow motion to see what happens.
The display is refreshed about 8 times in a second (too fast to follow in real time) and I was able to draw a nice curve (excel).
Really time consuming but this would be a way to find out the correction factor, in fact PLX told me to trust the display...
Trending Topics
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Oct 2003
Posts: 1,066
Likes: 1
From: Zurich - Switzerland
Yes, it works. As said, the correction isn't a problem, it's just that the values I see using Atap are too raw for a nice AF log (because it rounds up the numbers).
Looking at the display during WOT it's a little dangerous: 2nd gear goes up to 90 mph and I do log on the highway...
Looking at the display during WOT it's a little dangerous: 2nd gear goes up to 90 mph and I do log on the highway...
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Five Reasons the Camaro Was the Most Pivotal Player in the Pony Car Wars 2.0
Brett Foote
10 Reasons the LS7 Is GM's Most Extreme Naturally Aspirated V8 Engine Ever
Verdad Gallardo
Tici- I have not quantified the issues that you noticed. However, my M-300 appears to display about .1 AFR above stoich when both shortband O2's are averaging stoichiometric. The M-300 analog output seems closer to the shortband O2's.
In otherwords, when car is in closed loop, M-300 display spends more time above 14.7 than below. Its too bad we cant increase the time average on display. It has too much resolution.
In otherwords, when car is in closed loop, M-300 display spends more time above 14.7 than below. Its too bad we cant increase the time average on display. It has too much resolution.
Thread Starter
TECH Fanatic
iTrader: (1)
Joined: Oct 2003
Posts: 1,066
Likes: 1
From: Zurich - Switzerland
Same here: during cruising I see an AF average of 14.9. THis is not the WB output but the display.
I'll soon try to use the narrow band output to the PCM and compare the LTFT before - after. Just to see how precise is this thing...
I'll soon try to use the narrow band output to the PCM and compare the LTFT before - after. Just to see how precise is this thing...
