Road tuning with OFT

[steve99]

Originally Posted by solidONE

That log was done with tactrix? I might get one just for the logging capabilities. Would save me a lot of time.

yes was done with tactrix , currently ony have logging addresses for roms C and G series although tdd can probably dig out the parameters for auto roms, but might require a bit of testing.

you can do about 20 parameters at about 20 times a sec. multiple logs and you can use at least a 4Gb mem card

[MFB]

Originally Posted by steve99

@Kodename47

dug up an old log where I had a bit of knock.

It using Tactrix to log and parameters provided by open source romraider guys but it appears to show that KCA can be 0 or negitive ? and that even when KCA =0 the FLKC correction is applied to the total timing value.

Assuming the log parameters RAM addresses and scaling are correct.

although in some areas it does not seem to add up unless some other compensations are being applied.

http://datazap.me/u/steve99/98-knock...zoom=2020-2314

Your log is showing flkc even if kca is already 0. However flkc removes from total timing. There may be hidden compensations that have not been defined that could explain this (add or subtract from total timing)

[BuBlake]

I have a few questions when tuning AFR.

First and foremost, the AFR when I log does not match the open loop fueling table. For example, I am supposed to be getting 11.8 or so at 1.4 load, 6k rpm, but instead at wot I am basically always getting a commanded AFR of 11.25:1. What is causing this? Thanks

(Edit: For future thread readers, this becomes kind of confusing... I wasn't looking at commanded AFR... I was actually looking at the measured AFR in logs and thinking it was commanded. Read further to see that we eventually figure this out, then everything becomes pretty straightforward. OFT has both a commanded AFR output and AFR output in logs. "AFR" means "measured AFR" in logs.)

[steve99]

Originally Posted by BuBlake

I have a few questions when tuning AFR.

First and foremost, the AFR when I log does not match the open loop fueling table. For example, I am supposed to be getting 11.8 or so at 1.4 load, 6k rpm, but instead at wot I am basically always getting a commanded AFR of 11.25:1. What is causing this? Thanks

most likelyOpen loop MAF scaling off

O2 sensor inaccurate
Exhaust or intake leaks.

[BuBlake]

Originally Posted by steve99

most likelyOpen loop MAF scaling off

O2 sensor inaccurate
Exhaust or intake leaks.

My LTFT is usually <4%, so I thought my MAF scaling was good... or at least keeping it from sticking me with a 11.25 AFR! Any idea what table it is pulling the 11.25 from? A compensation table?

btw running 93 now, so ltft is usable.

Here's a log: http://www.datazap.me/u/tuner1b/93-o...6?log=0&data=1

[steve99]

Originally Posted by BuBlake

My LTFT is usually <4%, so I thought my MAF scaling was good... or at least keeping it from sticking me with a 11.25 AFR! Any idea what table it is pulling the 11.25 from? A compensation table?

btw running 93 now, so ltft is usable.

Here's a log: http://www.datazap.me/u/tuner1b/93-o...6?log=0&data=1

If you fuel trims are less than 4% then your Closed loop maf scaling is ok this is generally the lower swction of the scale to around 3v or so.

What will be out is the OPEN Loop maf scaling during WOT.

The ECU looks at the OL Fuel table and the maf volts for the flow rate makes a calculation as to amount of fuel needed then applies the LTFT compensation and that's the fueling.

While the O2 sensor reads the result during WOT no correction is applied as a result of the 02 sensor reading during WOT (open loop fueling).

So its probably just you OL MAF scaling that off a bit.

Just be carefull if you adjust maf scaling to bring the afr leaner and closer to OL FUEL table as you may run into knock issues.

do you have aftermarket intake FA20 club by any chance

[solidONE]

Originally Posted by BuBlake

My LTFT is usually <4%, so I thought my MAF scaling was good... or at least keeping it from sticking me with a 11.25 AFR! Any idea what table it is pulling the 11.25 from? A compensation table?

btw running 93 now, so ltft is usable.

Here's a log: http://www.datazap.me/u/tuner1b/93-o...6?log=0&data=1

STG 2 OTS tune? The OTS maf scale on the stg2's seem to be a bit generous. @Wepeel's stg 2 logs looked exactly like this. He is running the factory front pipe with just a UEL Borla header IIRC.

[steve99]

Originally Posted by BuBlake

I have a few questions when tuning AFR.

First and foremost, the AFR when I log does not match the open loop fueling table. For example, I am supposed to be getting 11.8 or so at 1.4 load, 6k rpm, but instead at wot I am basically always getting a commanded AFR of 11.25:1. What is causing this? Thanks

I think I misread this post if your COMMANDED AFR is always 11.25 then I suspect a logging problem if you have OFT talk to the openflash guys the RAM address or scaling looks like it might be off for your ROM

[Wepeel]

Originally Posted by solidONE

STG 2 OTS tune? The OTS maf scale on the stg2's seem to be a bit generous. @Wepeel's stg 2 logs looked exactly like this. He is running the factory front pipe with just a UEL Borla header IIRC.

It was just a little different - mine seemed to peg 11.25 as it crossed 5k RPM at full load, but seemed to be mostly close to targets before that at most loads in OL or CL. I think with more driving it's gotten a little better, takes longer to hit 11.25, but it still gets there.

I have since added a Berk HFC and am replacing the Borla with an OFH. I noticed the Borla was showing leaks at all 3 flanges - I'm sure that was not helping the AFR, but not sure how much of an effect it would have. Hopefully with the OFH it will make things better - obviously the OFT is tuned specifically for it and from what I've seen it flows better than the Borla at higher RPM.

[Kodename47]

Out of interest, what does Shiv map the stock O2 down to? Are we getting commanded AFR and AFR muddled? And is the O2 mapping only down to 11.25, hence why people are seeing it "pegged" there?

[Td-d]

Rich maximum on stock O2 sensor is limited to 0.75 lambda, yes. So 11.025 AFR.

[BuBlake]

Originally Posted by steve99

If you fuel trims are less than 4% then your Closed loop maf scaling is ok this is generally the lower swction of the scale to around 3v or so.

What will be out is the OPEN Loop maf scaling during WOT.

The ECU looks at the OL Fuel table and the maf volts for the flow rate makes a calculation as to amount of fuel needed then applies the LTFT compensation and that's the fueling.

While the O2 sensor reads the result during WOT no correction is applied as a result of the 02 sensor reading during WOT (open loop fueling).

So its probably just you OL MAF scaling that off a bit.

Just be carefull if you adjust maf scaling to bring the afr leaner and closer to OL FUEL table as you may run into knock issues.

do you have aftermarket intake FA20 club by any chance

I am running FA20club CAI, Borla UEL Headers, Invidia FP, Invidia Q300 catback. No cats...

The AFR is pegged at 11.25 above 5k or so. Take a look at my logs if you want to see exactly what's going on.

I'm confused by what you said about the MAF scale being the culprit...

Let's say the intake is flowing more air than the MAF sensor scaling says it is. For example: Chart says at 3v the intake should be flowing 150cfm, but we're actually getting 200. Far as the ecu knows, it's still getting 150cfm and will continue to command the the fuel injectors according to the open loop fueling table.

In other words, isn't the MAF scale irrelevant if all I am trying to do is get the ECU to command a 12:1 AFR instead of a 11.25:1 AFR?

I thought the only sensor the ECU payed attention to in open loop fueling was the knock sensor? Back to the drawing board. lol

[Shiv@Openflash]

Originally Posted by BuBlake

I am running FA20club CAI, Borla UEL Headers, Invidia FP, Invidia Q300 catback. No cats...

The AFR is pegged at 11.25 above 5k or so. Take a look at my logs if you want to see exactly what's going on.

I'm confused by what you said about the MAF scale being the culprit...

Let's say the intake is flowing more air than the MAF sensor scaling says it is. For example: Chart says at 3v the intake should be flowing 150cfm, but we're actually getting 200. Far as the ecu knows, it's still getting 150cfm and will continue to command the the fuel injectors according to the open loop fueling table.

In other words, isn't the MAF scale irrelevant if all I am trying to do is get the ECU to command a 12:1 AFR instead of a 11.25:1 AFR?

I thought the only sensor the ECU payed attention to in open loop fueling was the knock sensor? Back to the drawing board. lol

The intake isn't flowing more air than stock. What is happening is that the MAF sensor element is reading a "sliver" of air which isn't a good representative of total airflow through the MAF housing. That's why the MAF calibration table would need to be remapped to achieve something closer to your AFR targets. Better solution might just be to put the factory airbox in.

[BuBlake]

Originally Posted by Shiv@Openflash

The intake isn't flowing more air than stock. What is happening is that the MAF sensor element is reading a "sliver" of air which isn't a good representative of total airflow through the MAF housing. That's why the MAF calibration table would need to be remapped to achieve something closer to your AFR targets. Better solution might just be to put the factory airbox in.

Is that just an assumption or do you know that the Fa20club actually flows less at any given RPM? I understand that the MAF sensor just measures a sliver which is why it needs to be calibrated for different intakes. MAF sensor outputs the amount of voltage needed to keep its wire at a specified temperature.(what is that temperature anyways?)

If I'm not mistaken, AFR target(or commanded AFR) is what I am seeing in the logs when in open loop fueling. I would understand if my AFR readings from a wideband O2 sensor were 11.25:1 when they were commanded 11.8:1 if my MAF scale was poorly calibrated, but not my commanded AFR. Why would the ECU change the AFR target? Is it going into limp mode? Is it making educated guesses from what it experienced in closed loop fueling, in a sense?