MAF Scaling - Open/Closed Loop Fueling info

[solidONE]

Originally Posted by Kodename47

You can load multiple logs into it, no need to join them up

did not know that... and ive been using it for couple years haha. Is there a new version, or it's been like this?

[Kodename47]

Originally Posted by solidONE

did not know that... and ive been using it for couple years haha. Is there a new version, or it's been like this?

If you've not updated in ages then there will be a newer version so download it again anyway. It has some very sweet features.

It has been able to use multiple files for some time though. Just add the logs/run data before you hit the Go button.

[Kayysonie]

I am trying to understand this whole MAF Scaling thing.
basically, Scaling the MAF will give better Fuel to Air ratio that will make the run happy.
I see benefits in Milage and Power.

Standard OFT Tunes are tuned for stock air box/inlet.

Can the OFT tune still adjust w/o adjusting MAF Scaling to just inlet modification like the Perrin or AVO or Zeta and still keep the stock airbox?

[steve99]

Originally Posted by Kayysonie

I am trying to understand this whole MAF Scaling thing.
basically, Scaling the MAF will give better Fuel to Air ratio that will make the run happy.
I see benefits in Milage and Power.

Standard OFT Tunes are tuned for stock air box/inlet.

Can the OFT tune still adjust w/o adjusting MAF Scaling to just inlet modification like the Perrin or AVO or Zeta and still keep the stock airbox?

MAFis a mas air flow sensor, its job is to measere the amount of air flowing into the engine so the ecu can accuratly inject the correspinding amount of fuel as per the various fueling tables in the ecu. The maf value is also used as an input to thge ecu load calculation and many ecu tables for ignition timing cam timing fueling use the load value. ie the maf is very important .

The maf sensor does not measure the total volume of air, it measures a small sample then a offset is applied to estimate the total volume of air, part of this is the maf scale.
If you change the positioning of the maf sensor or the size of the tube the maf sensor sits in then this calculation is now incorrect and maf scaling is required.
Some intakes remove the air straightner that smooths airflow over maf, or place maf sensor two close to throttle body or on a sharp bend, these thing make the air flow unpredictable due turbulance ect and make rescalling maf difficult.

Scaling the maf even on stock intake will ensure the mas air flow and load calculations are correct for your car and ensure you tun the fueling and timing that are in the ecu tables as accuratly as possible.

sometimes rescaling maf may result in you hitting different load cells in fueling or timing tables and further adjustments to tables may be required.

[tracerit]

I'm starting to look into MAF scaling to prepare myself when I install my Perrin 3" CAI and switching to E85 however when I open up RomRaider, it can not download the new ECU Definitions since the link is down. Stupid question, but can I use the XML file from the OFT 2069 tune download?

[Kodename47]

Originally Posted by tracerit

I'm starting to look into MAF scaling to prepare myself when I install my Perrin 3" CAI and switching to E85 however when I open up RomRaider, it can not download the new ECU Definitions since the link is down. Stupid question, but can I use the XML file from the OFT 2069 tune download?

http://www.ft86club.com/forums/showp...&postcount=414

[steve99]

Originally Posted by tracerit

I'm starting to look into MAF scaling to prepare myself when I install my Perrin 3" CAI and switching to E85 however when I open up RomRaider, it can not download the new ECU Definitions since the link is down. Stupid question, but can I use the XML file from the OFT 2069 tune download?

just make sure your rom and definition match please read the romriader tips link below
especially if you r editing launch and ffs patch parameters.

dont use the romraider application to try to download defs,download your defs from oft or romraider sites ect directly depending on which type of rom your editing.

[MGPAX]

Originally Posted by steve99

ol cl transition should be arround 3v maybe 3.2 v

closed loop fueling mode is 2
open loop is 4

make sure your not logging injection mode that is port\direct injection.

I just went to check and make sure I'm not logging injector mode. In my '14 AT it seems that anything other than holding speed or hwy driving is in OL. I thought I may be logging the wrong thing.

It's actually difficult to log CL in my car because it switches to OL so easily.

Any ideas on how to keep the car in CL more often?

Pax

[steve99]

Originally Posted by MGPAX

I just went to check and make sure I'm not logging injector mode. In my '14 AT it seems that anything other than holding speed or hwy driving is in OL. I thought I may be logging the wrong thing.

It's actually difficult to log CL in my car because it switches to OL so easily.

Any ideas on how to keep the car in CL more often?

Pax

steady or slow throttle movements
light throttle

[MGPAX]

Originally Posted by steve99

steady or slow throttle movements
light throttle

Thanks!
I must have a serious lead foot!! LOL
It was very hard to keep this car in CL. I did it. But even up a little hill on the interstate at 70 with cruise on it goes in OL for a bit.


Pax

[Wayno]

Originally Posted by MGPAX

Thanks!
I must have a serious lead foot!! LOL
It was very hard to keep this car in CL. I did it. But even up a little hill on the interstate at 70 with cruise on it goes in OL for a bit.


Pax

Change the throttle map.

You're pissing in the wind adjusting CL on Stg1 anyway imo. Get some headers!

[tracerit]

I just installed my Perrin BigMAF CAI and have only driven 10 miles with Perrin's provided MAF scale. Is there a minimum time frame before I start logging to customize the MAF scaling to my car?

[steve99]

give it say 50 miles for ltft to stabilise a bit the do some logging, the perrin scaling is a fair bit off.

[solidONE]

Originally Posted by Kodename47

It's just individual data points. If you think you're getting good data, reduce the dV/dt filter, I usually use 0.3 or 0.35. It will massively reduce the data but make it far more reliable, you need a long log though. You can always rerun the same file with different filters to see how it changes the results. Also, I do set max AFR to 16 so that I capture as much data as possible.

The recorded fuel trims captured while leaner than a stoichiometric target of 14.7:1 is no good, no? I've been setting mine at 15...