General 2gNT SAFC seems to be tuning backwards

[thatblondechik]

Alright, so I'll be the first to admit I'm not the best at tuning. But I'm not THIS bad.

I recently installed a TurboXS TunerPro (would have preferred just a wideband but it was a gift so I'm not complaining). Once installed I started to try to tune my idle. I immediately noticed something was screwy to say the least.

Setup:
MAFT (Zero'd out, only translating signal)
SAFC
680's
Aeromotive AFPR (set at 42psi)
Walbro 255

Global: 35% and 80%
LO: -35%

Now right after I set my LO, I noticed the wideband spike up to 19-21:1 (fluctuating). Now like I said, I'm not very good at tuning but this obviously didn't seem right. The AFC had been Zero'd out before and was sitting at about (according to the wideband) 15:1.

Now at first I thought this might be the result of my MAFT richening out at startup. So I correct the MAFT, shut the car off, and restarted...still fluctuating from 19-21. I decided to play with it a little just to see what happened and corrected +50% in LO and BOOM I get an instant 12:1.

Tomorrow (if I can get it started, I think the starters about to bite the dust) I'm gonna zero the AFC again and see what happens when I try to compensate for injectors on the MAFT. But this has me absolutely BAFFLED! Any ideas of what I can try tomorrow?

 

[CanadianTSi]

IIRC when I was running 650's/S-AFC my Lo settings were in the -8 to -15 range.

 

[thatblondechik]

IIRC when I was running 650's/S-AFC my Lo settings were in the -8 to -15 range.

IIRC? Educate me.

My main WTF is why I'm seeing close ideal trims at +50%. That makes absolutely no sense to me or any of the people I've spoken to.

 

[2GturboTALON]

IIRC=if i recall correctly. Now have u tried to reset the ecu and start fresh ?

 

[toofast82]

IIRC when I was running 650's/S-AFC my Lo settings were in the -8 to -15 range.

Did you have all your honeycombs intact?
A good base setting would be -30 with 650cc, wondering if you had something else that would cause that little compensation.

 

[->PrOjEcTGS<-]

^^ Correct it should be about a -30% across the board on your SAFC LO setting. What do your fuel trims tell you? Your wideband could possibly be bad?

 

[thatblondechik]

ECU's been reset plenty of times over the past 4 months.

-30% is close enough to what I had and the higher I set the AFC the LEANER my wideband would read. I guess it's possible the wideband could be bad, but it's a brand new setup (this is the first time I've used it). Brand new Bosch sensor. I don't see it screwing up this bad.

I know TurboXS is more of a Subie thing so I asked a Subie friend of mine who used to have the same logger. He said something about "free air calibration." I've never heard of this and can't find much about it. It involves giving the sensor a base reading in, you guessed it, "free air" (ie. not in the exhaust).

Also, I was out messing with it today, and the starter is indeed shot. So until I can buy a new one I won't be able to test anything. I'll revive this thread once I reach that point.

 

[donniekak]

Usually with larger injectors and an afc the very lowest range of the correction factors (under 1000 rpm's) is way different than the rest of the range. This is due to the increased deadtime of the larger injectors.

 

[CanadianTSi]

Did you have all your honeycombs intact?
A good base setting would be -30 with 650cc, wondering if you had something else that would cause that little compensation.

Nope, all honeycombs intact. No need to remove them on a 2G, I can flow 50lbs/min through them without missing a count...

 

[toofast82]

a Subie friend of mine who used to have the same logger. He said something about "free air calibration." I've never heard of this and can't find much about it. It involves giving the sensor a base reading in, you guessed it, "free air" (ie. not in the exhaust).

This is necessary when using an Innovate LC-1 and i'm sure other Innovate widebands. I do not believe there is any calibration really for the AEM wideband.

After reading I see this Tunerpro has a built in wideband controller and may very well require the "free air calibration" as your friend mentioned.