Questions about ECU parameters

GeorgeRex · 07-03-2006, 04:06 PM

1.) Is there a reason to change or not change the max airflow value (300 g/s)? Does the ECU respond to this value in some way? I am hitting MAF voltage values between 4.75 and 4.80 which hypothetically are higher than 300 g/s already.

2.) Could someone please give some tips on how to set the throttle position values so that it does not start closing at 6800 rpm. Where is the table found, what is it called in the directory? I couldn't make sense of the existing thread on this subject.

Thanks, ST gurus!

crystal_Imprezav · 07-04-2006, 09:54 AM

Most intakes will not throw a value over 300 unless in the cold or using a larger MAF housing. With that being said, I have mine set a 500 even though I have never seen any values over 300 to this day. Its more of a precaution for me so that in case I do, the ecu doesn't do anything to 'learn' and throw some of my parameters off like the AFR and KC.

daemon · 07-04-2006, 10:27 AM

If you are exceeding 300g/s, then that is the reason to increase it.

The ECU calculates fueling from that number, not from the MAF voltage itself, as I understand it. So if you are exceeding 300g/s, but the ECU limit is truncating the value to 300g/s, then you will have a natural tendency to lean out the farther over that limit you go. I have no personal experience logging the leaning, that is just my understanding. I can exceed 300g/s and have my limit set at 500 also (dare to dream).

I believe the table you want is the Throttle Duty Cycle table in the Misc Tables folder. WolfPlayer is the guru there, but it looks like the stock map doesn't start to shutdown the throttle until 6900 RPM. You can change a few of the RPM axis values and then have it start closing later.

07-03-2006, 04:06 PM	#1
GeorgeRex Junior STI Driver Posts: 186 Join Date: Feb 2004 Trader Rating: (0)	Questions about ECU parameters 1.) Is there a reason to change or not change the max airflow value (300 g/s)? Does the ECU respond to this value in some way? I am hitting MAF voltage values between 4.75 and 4.80 which hypothetically are higher than 300 g/s already. 2.) Could someone please give some tips on how to set the throttle position values so that it does not start closing at 6800 rpm. Where is the table found, what is it called in the directory? I couldn't make sense of the existing thread on this subject. Thanks, ST gurus! This ad is not endorsed by this member. Please register or login to hide this ad.

07-04-2006, 10:27 AM	#3
daemon The Next Petter Solberg Car: 2004 STi Location: Florida Posts: 855 Join Date: Feb 2004 Trader Rating: (0)	If you are exceeding 300g/s, then that is the reason to increase it. The ECU calculates fueling from that number, not from the MAF voltage itself, as I understand it. So if you are exceeding 300g/s, but the ECU limit is truncating the value to 300g/s, then you will have a natural tendency to lean out the farther over that limit you go. I have no personal experience logging the leaning, that is just my understanding. I can exceed 300g/s and have my limit set at 500 also (dare to dream). I believe the table you want is the Throttle Duty Cycle table in the Misc Tables folder. WolfPlayer is the guru there, but it looks like the stock map doesn't start to shutdown the throttle until 6900 RPM. You can change a few of the RPM axis values and then have it start closing later. This ad is not endorsed by this member. Please register or login to hide this ad.

07-04-2006, 09:54 AM	#2
crystal_Imprezav Spec C Club Car: Slow 05 STi Fav Mod: Loping Idle Location: Chewy's Garage Posts: 1,873 Join Date: Mar 2005 Trader Rating: (11)	Most intakes will not throw a value over 300 unless in the cold or using a larger MAF housing. With that being said, I have mine set a 500 even though I have never seen any values over 300 to this day. Its more of a precaution for me so that in case I do, the ecu doesn't do anything to 'learn' and throw some of my parameters off like the AFR and KC.