afr parameters

[stanger383]

I have an 05 A4 C6 with h\c and usual bolt ons. I get an afr of around 11.9 in first gear and then close to 12.8-9 in second and third gear. The pe table is rpm based so how do I try to make it more consistant? Thanks, Norm

[DSteck]

Did you just wreck the PE table, or did you truly tune the MAF and SD?...

I've found that cars with raped PE tables don't run consistent from gear to gear, but cars that have been done correctly will crap out the same AFR in every gear.

[CDODSON]

I am tuning my 05 C6 A4 (ARH Headers w/ cats, Callaway Honker CAI, 160 stat) as well.

I get low to mid 14.1 - 14.5 when crusing - the occasional 13.8. LTFT are mostly within +/- 5%.

Car runs nice and smooth. I do get a P0420 and P0430. Unable to tune that out. I finally switch the reporting to "3". We'll see how that works.

Track tuning has got me a 12.32 @114 so far.

I'd like to hear your results once you get straightened out.

Bottom line for me - Spent a lot of time with VE and MAF tables. AFR is still a little rich.

Good luck

[stanger383]

I tuned the maf by adjusting using hz. No sd tuning. My ltft are all 0 to -4 typically. What is wrecking the PE table? I logged afr with my wideband and when pe table was 1.18 it was 11.6 afr I went to 1.13 it went to 12.1. Im at 1.08 now and it is leaner through first gear and richer in 2nd and 3rd. It might sound stupid but what is raping or wrecking the PE table???

[superwagon]

I tuned the maf by adjusting using hz. No sd tuning. My ltft are all 0 to -4 typically. What is wrecking the PE table? I logged afr with my wideband and when pe table was 1.18 it was 11.6 afr I went to 1.13 it went to 12.1. Im at 1.08 now and it is leaner through first gear and richer in 2nd and 3rd. It might sound stupid but what is raping or wrecking the PE table???

Raping or wrecking your PE table is adjusting your pe table to get your desired fueling rather than adjusting your maf to get what you are commanding from your pe table.

[stanger383]

I tuned my MAF. there is an error from what is commanded to what the wideband reads. My wideband reads 14.3-14.7 at cruise and idle. Is there something else to adjust to decrease the discrepancy from commanded afr to actual afr?

[DSteck]

I tuned my MAF. there is an error from what is commanded to what the wideband reads. My wideband reads 14.3-14.7 at cruise and idle. Is there something else to adjust to decrease the discrepancy from commanded afr to actual afr?

The statement that is in bold means you did NOT calibrate your MAF during power enrichment, and instead you are just raping your PE table to get an end result.

If you want a 12.5 AFR, then your PE table needs to be 1.176 across the board, and your MAF needs to be recalibrated to make the actual AFR match the commanded AFR. Read up on MAF tuning and how to create a wideband error that works the same as a fuel trim.

[markislive]

Also make sure your wideband display and HPT readings are spot on....

[stanger383]

ah ha ok.. so in just the way that I dialed in the maf up to 6k hz I continue on up to 12k. That makes sense. Am i correct in that thinking? So in short....if my actual afr is 12.0 when commanded 13.0then i will multiply the maf numbers in those hz cells by .92 aprox. to start. is that the proper way?

[markislive]

ah ha ok.. so in just the way that I dialed in the maf up to 6k hz I continue on up to 12k. That makes sense. Am i correct in that thinking? So in short....if my actual afr is 12.0 when commanded 13.0then i will multiply the maf numbers in those hz cells by .92 aprox. to start. is that the proper way?

VCM Scanner can log can wideband AFR error % in hz table when setup properly, all you have to do is copy the % error from scanner and paste special/multiply by % into the MAF table...

[stanger383]

I do not have hp pro so i am forced to use the lm1 separately. I can correspond rpm to hz if I compare my lm1 log to my vcm log and translate lm1 rpm to Hz. does that change the last pointer you gave me?

[markislive]

I do not have hp pro so i am forced to use the lm1 separately. I can correspond rpm to hz if I compare my lm1 log to my vcm log and translate lm1 rpm to Hz. does that change the last pointer you gave me?

Ohhh shit, ur doing this by hand... Never messed with that, sorry wish I could help...

[DSteck]

Your general approach is correct. You should look into logging your LM1 in through the AC pressure sensor though... it will make your life easier.

[stanger383]

a friend of mine is going to let me use his hp pro cable for when i am scanning so i can feed the lm1 right into hp tuners

[vortec]

use a wideband.In order to get everything dialed in correctly,you need a wideband.

[stanger383]

I have a wideband. here is my first log after my first cal. of the maf hi table. i was commanding 12.45 afr (1.18 pe table). after that log i fine tune it some more. I am doing it by hand by writing down the Hz vs afr and making a list then modifying editor. thanks for the help so far! frame 2600 is a low rpm stab in second gear so it wouldnt spin and skew results. that is the main part of the log im working with. Feel free to point out other issues if see any.