EQ ratio Commanded VS AFR Commanded for 2014 Coyote FRPP ecu

[hakeem]

Hi All,

Sorry if this is a dump question. I am still new to this and a little confused.

Now in the VCM Scanner Channel I can only add EQ commanded. there is no AFR Commanded Channel. I have Daytona sensor that is measuring AFR instead of Lamda and its kinda confusing.

So, I have few questions please;

1) if I changed the units on EQ commanded from Lamda to AFR 14.7 gasoline, is this same as AFR commanded?

2) I noticed in the original tune for FRPP ecu, it has the AFR stoich set to 14.08 (14.64 max and 9.85 min). does this mean that Lamda 1 = to 14.08?

Thanks
Hakeem

[ADuff321]

Yes lambda 1 will always be equal to stoich. Trying to change or convert units will probably only further confuse the situation since the vehicle is already equipped with widebands from the factory and the pcm really thinks in terms of lambda. It's musc easier to just think in terms of lambda because that takes into account the differences in fuel and ethanol content. Lambda is just the ratio to stioch of what ever particular fuel you are using and its associated stoich afr. The factory has it set to 14.08 because thas the stoich value for gasoline with 10 precent ethanol or E10 as its known, which is most commonly found in the gas pumps across the USA. you can use an external wideband if you like but it's really only going to be like a triple check that the factory ones are working right since you can already cross check them to eachother (and the pcm does this on its own as well).

[hakeem]

Yes lambda 1 will always be equal to stoich. Trying to change or convert units will probably only further confuse the situation since the vehicle is already equipped with widebands from the factory and the pcm really thinks in terms of lambda. It's musc easier to just think in terms of lambda because that takes into account the differences in fuel and ethanol content. Lambda is just the ratio to stioch of what ever particular fuel you are using and its associated stoich afr. The factory has it set to 14.08 because thas the stoich value for gasoline with 10 precent ethanol or E10 as its known, which is most commonly found in the gas pumps across the USA. you can use an external wideband if you like but it's really only going to be like a triple check that the factory ones are working right since you can already cross check them to eachother (and the pcm does this on its own as well).

Thanks!
let me just check if I got this correctly;

1) So, here in Qatar. I have been told that the Stoich AFR is 14.2. So, I can change 14.08 to 14.2?
2) Also, I have Daytona vi wide band kit. and I have been told that I can change it to Lambda readings. So, when I do this I have to choose Lambda 1 = 14.2?

right?

Thanks Again

[ADuff321]

1. Yes you can do that change to 14.2 if you want but the difference between the 2 is less than 1 percent from 14.08 to 14.2 so I wouldn't. Also they may be assuming that is stoichow by you because GM likes to use that as its stoich value in the pcm on its newer vehicles. To really know you would have to test the fuel you are using for alcohol content and equate from that tested fuel what your stoich value is. But that's a lot of work to determine what the Ford value is probably very close to (probably within 1 percent). Unless you have no alcohol in the fuel then ford would use a 14.64 afr for its stoich value.

2. The problem with Daytona sensors software as of the last time I checked is that they do not allow you to change the stoich value in there calibration software. And they have it preconfigured for a 14.7 afr as stoich

[hakeem]

ok. I really dont know if i get it or I am just confused! let me try to explain what I understood from this. sorry I know its too much but please bear with me.

So,

1) lets say I am using VCM scanner with FRPP ecu while Idle. the EQ Commanded = 1 lambda (that means its 14.08)
2) lets forget the WEGO Single Channel Data Logging software.
3) I connected Daytona vi wideband sensor to my HPtuners as per the tuning school video. I did the free Air calibration for the sensor. And I added the MPVI1 Channel in vcm scanner for this sensor as per the video. So, the reading on this channel when the car is idling should display 14.08?

[ADuff321]

it will fluctuate but should be close to 14.08 as long as your daytona sensor is completely in the exhaust stream and the nearer the exhaust manifolds the better

[smcstevesmc]

[QUOTE=ADuff321;485147]it will fluctuate but should be close to 14.08 as long as your daytona sensor is completely in the exhaust stream and the nearer the exhaust manifolds

My gas has 10% ethanol, yet I see 14.7 afr.