How do I know if wide band is right?
03-30-2011, 07:29 AM
#1
How do I know if wide band is right? I have an NGK AFX wideband hooked up to a HP Tuners EIO.
I tuned my vette last fall and Im wondering if the widebands values were not even close?? My idle A/F was around 14-15:1 according to this WB (os so i think). I had some high idle problems and cut the table almost in half to get it to idle perfect.
I also tuned a friends car that he sold..... cruise/idle was around 14-15:1 and when you got on it, it went to 12.2:1 up till about 4000 rpms and then to about 12.8:1 No knock at all. He sold the car and the new guy had it tuned on a dyno.... he said it was extremely lean....dangerously lean. Car put down a little over 300whp when he brought it there, but after adding fuel went to like 406whp. Seems kind of a big jump..... but I do question my WB's readings.
Im at work right now so I can access my configuration file for the WB... but does anyone else use the AFX? And with HP Tuners EIO? If so what formula did you put in the config file?
I tuned my vette last fall and Im wondering if the widebands values were not even close?? My idle A/F was around 14-15:1 according to this WB (os so i think). I had some high idle problems and cut the table almost in half to get it to idle perfect.
I also tuned a friends car that he sold..... cruise/idle was around 14-15:1 and when you got on it, it went to 12.2:1 up till about 4000 rpms and then to about 12.8:1 No knock at all. He sold the car and the new guy had it tuned on a dyno.... he said it was extremely lean....dangerously lean. Car put down a little over 300whp when he brought it there, but after adding fuel went to like 406whp. Seems kind of a big jump..... but I do question my WB's readings.
Im at work right now so I can access my configuration file for the WB... but does anyone else use the AFX? And with HP Tuners EIO? If so what formula did you put in the config file?
03-30-2011, 07:54 AM
#3
The biggest thing I had an issue with was making sure the HPT Scanner was set up appropriately - for the longest time, I didn't have the input calibration scaled correctly, so even though the wideband was saying one thing, it wasn't being scaled properly in the datalogs, so I was making incorrect fueling adjustments. My first clue was when I hooked up a gauge to the wideband, and compared the two - after that, everything has been as good as I can expect. I trust it, but know that it could potentially be wrong...that is the risk you run with any measurement tool.
Widebands can always be recalibrated, and I usually do so before going out on a long tuning excursion.
As for the other issue you had, there's nothing to say there wasn't some other underlying issue like a fuel pump going out, although if that was the case, he probably wouldn't have been able to get the A/F ratio back in line.
Widebands can always be recalibrated, and I usually do so before going out on a long tuning excursion.
As for the other issue you had, there's nothing to say there wasn't some other underlying issue like a fuel pump going out, although if that was the case, he probably wouldn't have been able to get the A/F ratio back in line.
03-30-2011, 10:56 AM
#5
11 Second Club
iTrader: (8)
Join Date: Jan 2002
Location: SILSBEE TX
Posts: 1,782
Likes: 0
Received 0 Likes
on
0 Posts
"....Car put down a little over 300whp when he brought it there, but after adding fuel went to like 406whp. Seems kind of a big jump..... "
kind of a big jump? I find it hard to beleave that the car was driveable if the tune was off over 100 hp
Just me, Johnny
kind of a big jump? I find it hard to beleave that the car was driveable if the tune was off over 100 hp
Just me, Johnny
03-30-2011, 12:08 PM
#6
TECH Fanatic
iTrader: (1)
Join Date: May 2004
Location: Northern WV just south of MD
Posts: 1,016
Likes: 0
Received 0 Likes
on
0 Posts
When in closed loop control the A/F ratio increase and decrease about 14.4 as the short trim factors adjust the air fuel ratio. I just look for the roll around 14.4 driving down the road.
03-30-2011, 12:18 PM
#7
Yea... I know. I Find it hard to believe also. But my lean idle issue I just had with my vette made me think of that.
Trending Topics
03-30-2011, 02:31 PM
#8
Moderator
iTrader: (11)
Join Date: Mar 2002
Location: East Central Florida
Posts: 12,605
Likes: 0
Received 6 Likes
on
6 Posts
You should use whatever wideband software came with
the thing, to read or assert the AFR-volts map. It's
easiest, if not ideal, to use factory defaults with the
tuning software / cable packages. My LM-1 seems to
revert to factory when the battery is replaced and I
get mis-scaled (against my preferred range settings)
logs until I remember to fix it.
Dynos like to use tailpipe sensors which are easy and
very unreliable. I'd trust a tool I owned and cared for
and was located right, over somebody else's every time.
But widebands can be spoofed by some things, like
misfires, as well. You have to keep an eye on what
they're telling you and have a sense of what's sane,
and chase down causes if something smells wrong.
the thing, to read or assert the AFR-volts map. It's
easiest, if not ideal, to use factory defaults with the
tuning software / cable packages. My LM-1 seems to
revert to factory when the battery is replaced and I
get mis-scaled (against my preferred range settings)
logs until I remember to fix it.
Dynos like to use tailpipe sensors which are easy and
very unreliable. I'd trust a tool I owned and cared for
and was located right, over somebody else's every time.
But widebands can be spoofed by some things, like
misfires, as well. You have to keep an eye on what
they're telling you and have a sense of what's sane,
and chase down causes if something smells wrong.
03-30-2011, 05:59 PM
#9
pwrtrip i use lambda and its
volts/10.42+.62 and i know the afr math is in the manual for the ngk, i just don't have it here in front of me. somewhere (here or hpforum) sound engineer does one of his famous 1000 word discertations on it.
04-05-2011, 06:04 PM
#10
It didnt come with software.
Ive been away from this thing for a week now.... now back at it.
I went through my config file and here is how I have it.
Volts/0.7143 + 9
I dont remember where I came up with that.... but How do I know what value to put in there. If I remember right the one in the manual it told me to put in was way off and the display on the WB was nowhere near what the HPtuners was saying.
Ive been away from this thing for a week now.... now back at it.
I went through my config file and here is how I have it.
Volts/0.7143 + 9
I dont remember where I came up with that.... but How do I know what value to put in there. If I remember right the one in the manual it told me to put in was way off and the display on the WB was nowhere near what the HPtuners was saying.
04-06-2011, 06:15 AM
#12
So the Volts/0.7143 + 9 is correct? Im questioning it a lot....thinking its leaner than its advertising.
Last night just messing around I changed the stoich value to 13.5 to see if it would make a difference.... and it did. Still idled perfect, seem to pull harder and it broke the tires loose going into 3rd pretty easy.... didnt do that before.
I think I need to start all over tuning this thing. But I want to know that what im reading is right.
Last night just messing around I changed the stoich value to 13.5 to see if it would make a difference.... and it did. Still idled perfect, seem to pull harder and it broke the tires loose going into 3rd pretty easy.... didnt do that before.
I think I need to start all over tuning this thing. But I want to know that what im reading is right.
04-06-2011, 07:21 PM
#15
Its the ratio im wondering about... I know its really close driving around low rpm.... when its around 14.5:1ish... but when im on it full throttle and cant study both readings... when it dips down to 12.5:1 I dont know because im not about to watch them while at full throttle closely....lol.. So unless I run it to the bottom of the scale which is either 9 or 10:1 to see if that is on, and then to the top of the scale to see... how else would you know?
Hope I make sense.
Hope I make sense.
04-06-2011, 09:24 PM
#16
Command a static airfuel ratio at WOT such as 12:1 and then when you have your airflow calculation dialed in correctly and you are achieving the 12:1 in your datalogger, then look at the wideband itself.
Personally I have 3 widebands on my dyno, 2 AFX and an AFM1000 and I can look at the graph of all 3 along with my datalogs on a seperate application and review it all after the run, but most people do not have these tools available.
Ryan
Personally I have 3 widebands on my dyno, 2 AFX and an AFM1000 and I can look at the graph of all 3 along with my datalogs on a seperate application and review it all after the run, but most people do not have these tools available.
Ryan
04-06-2011, 09:36 PM
#17
i think the answer is faith. i think ngk probably has there slope formula figured out. when i command a pe of .86 lambda and i log my ngk it will read close to .86 as long as my ve is correct. when i go into be and command .80, even if it's in the samc ve cell as my previous .86 reading , i will get around .80. i have little idea what the led gauge says. try this.
1.in your eio input 1, insert your wide band as volts/10.42+0.62 call it actuall lambda.
2.then make a pid for commanded lambda with [PID.6001]/14.68 wher pid6001 is your afr hi res and 14.xxx is your stoich afr.
3.is make another pid for lambda error 100*([AUX.20121]-[USER.9006])/[USER.9006] where the aux is your eio input in lambda, user 9006 is your commanded lambda.
put them all in your table
4. you can then make a histogram with the plotted pid lambda error , top axis rpm and row axis your map
this will give you all of the units in lambda to plot independant of your fuel type.
1.in your eio input 1, insert your wide band as volts/10.42+0.62 call it actuall lambda.
2.then make a pid for commanded lambda with [PID.6001]/14.68 wher pid6001 is your afr hi res and 14.xxx is your stoich afr.
3.is make another pid for lambda error 100*([AUX.20121]-[USER.9006])/[USER.9006] where the aux is your eio input in lambda, user 9006 is your commanded lambda.
put them all in your table
4. you can then make a histogram with the plotted pid lambda error , top axis rpm and row axis your map
this will give you all of the units in lambda to plot independant of your fuel type.
