[IneedAZ]

Originally Posted by Joshinator99

If you don’t install the flex sensor, stoichiometric stays at 14.1 because all gas, at least here in Northeast, is E10.

If you do install the E sensor, then you MUST rescale that table.

.82 Lambda works in both cases.

So, if he left it at 14.1 and is commanding .82 isn't that 11.5 afr and isn't that on the rich side? Or am I misunderstanding?

[Camaro1973]

Originally Posted by IneedAZ

So, if he left it at 14.1 and is commanding .82 isn't that 11.5 afr and isn't that on the rich side? Or am I misunderstanding?

.82 is 11.9AFR using stoich 14.1

[IneedAZ]

Originally Posted by Camaro1973

.82 is 11.9AFR using stoich 14.1

Then I must be using wrong formula. Thought it is afr/stoich..11.9/14.1 = .84

[JANNETTYRACING]

Originally Posted by Joshinator99

If the car is setup to run E, stoichiometric is set for 14.7 at 0% E, and scaled accordingly. Otherwise the car is set to 14.1 across the board and that would obviously not work. Lol

Originally Posted by IneedAZ

I'm not set to run e. I was curious if he changed the stoich from factory 14.1 to 14.7 when he said he tunes to .82 lambda. Cause 11.5afr seems rich but 12.0 i think is reasonable, but I could be wrong.

Originally Posted by Joshinator99

If you don’t install the flex sensor, stoichiometric stays at 14.1 because all gas, at least here in Northeast, is E10.

If you do install the E sensor, then you MUST rescale that table.

.82 Lambda works in both cases.

Originally Posted by IneedAZ

Then I must be using wrong formula. Thought it is afr/stoich..11.9/14.1 = .84

Stoich is different than lambda.

AFR to achieve Lambda is based on the fuel composition.

Lambda is the same across all fuels.

Set your wideband to read lambda and avoid all confusion.

All AFR gauges use a Lambda sensor and the gauge converts it to AFR based on a user input for the fuel they are running, Default is 14.7 for Pure Gasoline but you can go in the gauge settings and change Stoich value to match your fuel.

Since AFR changes with Ethanol content it is far too confusing to keep track of what normal readings are.

Lambda 1 is cruise and .82 is WOT.

The stock sensors are also lambda sensors but Narrow band which means they are only accurate at Lambda 1.

Any variation from Lambda 1 results in STFT which then transfers over to LTFT which ultimately is your Error from perfect calibration.

Ted.

[KingLT1]

Stoich AFR on a GAS scale is 14.7. E10 is 14.1.

.82 Lambda converted to a gas scale reading is 12.2 AFR.

.82 Lambda converted to a E10 scale is 11.9 AFR.

Look up the unit conversion in your VCM scanner. The options are Lambda(best), AFR for Methanol(6.4), Ethanol(9.0), Diesel(14.6), Gasoline(14.7). There is no E10 scale.

And for this reason, Unless you are running 100% gasoline, Lambda should be used as a reference for AFR... then if you want to see a reading on a gas scale you convert it using 14.7 not 14.1.

Now the confusion here is how WOT(PE) enrichment is calculated. The ECU uses the stoich value of the fuel you are running and divides it by the PE multiplier and that is the target AFR.

So if you are running E10 fuel then the ECU is taking the stoich value of 14.1 and dividing by PE numbers populated in the power enrichment table.

For example, 14.1 / 1.205 = 11.7 afr for E10 but that isn't gasoline AFR scale. You have to use Lambda then convert it back to AFR scale using 14.7.

And this is why Lambda is used to avoid all the confusion between different AFR's for different fuels. Lambda is 1 regardless of the fuel used.

[IneedAZ]

Also want to add I really appreciate the feedback. Just trying to fully understand it and hopefully it helps others too.

Also, what PE is being used to achieve the .82? Is it based on the 14.1 or 14.7 ? For example..my pe table is at 1.150 and my stoich set to 14.1, what is my Lambda then? .833?

[JANNETTYRACING]

Originally Posted by IneedAZ

Also want to add I really appreciate the feedback. Just trying to fully understand it and hopefully it helps others too.

Also, what PE is being used to achieve the .82? Is it based on the 14.1 or 14.7 ? For example..my pe table is at 1.150 and my stoich set to 14.1, what is my Lambda then? .833?

Lambda / 1.22

I can't say it enough stop with the AFR.

Set the Stoich value for the fuel you are burning, then use LAMBDA

I see this alot, Some how, some way, Tuners just don't understand how this works, you would think everyone who tunes would know this but they don't.

Quite honestly I have seen these discussions for many years and have tried to help but it continues.

I tune N/A DI cars at PE 1.16 Or .86 Lambda, and Boosted DI cars at PE 1.22 or .82 Lambda

PI cars are PE 1.18 or .85 Lambda and boosted PI cars PE 1.28 or .78 Lambda

1.15 on a boosted application PI or DI is insane.

Just because you command 1.15 does not mean you will achieve it that comes in the way of the MAF calibration.

Which means that if you are achieving .82 and PE is set to 1.15 then the MAF cal is a train wreck.

At the same time If Stoich value is not set correctly for the fuel you are burning another train wreck occurs.

Here is something to think about.

There is no such thing as an AFR sensor, but there are AFR gauges.

Ted.

[IneedAZ]

Originally Posted by JANNETTYRACING

Lambda / 1.22

I can't say it enough stop with the AFR.

Set the Stoich value for the fuel you are burning, then use LAMBDA

I see this alot, Some how, some way, Tuners just don't understand how this works, you would think everyone who tunes would know this but they don't.

Quite honestly I have seen these discussions for many years and have tried to help but it continues.

I tune N/A DI cars at PE 1.16 Or .86 Lambda, and Boosted DI cars at PE 1.22 or .82 Lambda

PI cars are PE 1.18 or .85 Lambda and boosted PI cars PE 1.28 or .78 Lambda

1.15 on a boosted application PI or DI is insane.

Just because you command 1.15 does not mean you will achieve it that comes in the way of the MAF calibration.

Which means that if you are achieving .82 and PE is set to 1.15 then the MAF cal is a train wreck.

At the same time If Stoich value is not set correctly for the fuel you are burning another train wreck occurs.

Here is something to think about.

There is no such thing as an AFR sensor, but there are AFR gauges.

Ted.

For my application, I do know my Stoich is set to 14.1. What i don't know is what my Lambda is at WOT as i have not made a pass since the tune and i don't have any of the logs from the dyno. My original Tune was set to 1.155 PE, and the new tuner changed it to 1.150. When i saw the dyno sheet, i also had seen it say AFR of 13:1. I don't know how their system is calibrated so i don't know its Lambda. He did say my Fuel pressure is holding now and not dropping like it did before. Also my INJ PW went from 6.2 to 5.2 with current tune. The current tune does have both MAF & SD now where as my original tune was MAF only. My concern is am i running to lean? Without seeing the log and seeing the Lambda i think i am in the dark. Did he push it lean since i wasn't showing any signs of KR? And was this cause i had 1/2 can of Boostane in the tank? I did look at my MAF table and the upper end of the scale numbers are lower than what i had from prior tune. Lastly, we did go 1 more step colder plug from what i had and did the Brisk plugs this time. I believe this plug puts me 2 steps colder than stock.


Either way, that is a big difference from what you have at 1.22 PE vs my 1.15. Odd that 2 different local shops want to run the car that much leaner than you. As mentioned original tune was 1.155 which is close to the 1.150 i have now. Also this makes me wonder if i should NOT try adding the e30 or e40 as suggested. I was hoping to move away from the Boostane by running e30 or e40.

[KingLT1]

Just because they are using 1.15 as a PE multiplier doesn't mean it's running lean.

If 14.1 is the number populated in the 0% column of the stoich table, then your ECU is using the Formula 14.1 / 1.15 = 12.26 target AFR.

Ted is using 1.22 because the 0% column of the stoich table is probably set to 14.7. 14.7 / 1.22 = 12.05

Either way, You should go out and log a pull... make sure you are logging your Wideband in Lambda and Maf vs EQ error in histogram. It's the only way to know instead of sit here on the forum and guess at it.

[IneedAZ]

Originally Posted by KingLT1

Just because they are using 1.15 as a PE multiplier doesn't mean it's running lean.

If 14.1 is the number populated in the 0% column of the stoich table, then your ECU is using the Formula 14.1 / 1.15 = 12.26 target AFR.

Ted is using 1.22 because the 0% column of the stoich table is probably set to 14.7. 14.7 / 1.22 = 12.05

Either way, You should go out and log a pull... make sure you are logging your Wideband in Lambda and Maf vs EQ error in histogram. It's the only way to know instead of sit here on the forum and guess at it.

Totally agree...Just been waiting til this coming sunday as i just finished cleaning it up for a car show..Maybe on the way home weather permitting i can do a wot test. And yes, that is why i wanted to know if Ted was using 14.7 or 14.1.

Again, appreciate everybody posting

[arpad_m]

Originally Posted by IneedAZ

Totally agree...Just been waiting til this coming sunday as i just finished cleaning it up for a car show..Maybe on the way home weather permitting i can do a wot test. And yes, that is why i wanted to know if Ted was using 14.7 or 14.1.

Again, appreciate everybody posting

For the record, this is specifically what King is alluding to. The stock tune has 14.1 across the board, because pump gas usually has 10% ethanol, but a proper flex fuel tune will change all stoich cells.

[JANNETTYRACING]

Originally Posted by KingLT1

Just because they are using 1.15 as a PE multiplier doesn't mean it's running lean.

If 14.1 is the number populated in the 0% column of the stoich table, then your ECU is using the Formula 14.1 / 1.15 = 12.26 target AFR.

Ted is using 1.22 because the 0% column of the stoich table is probably set to 14.7. 14.7 / 1.22 = 12.05

Either way, You should go out and log a pull... make sure you are logging your Wideband in Lambda and Maf vs EQ error in histogram. It's the only way to know instead of sit here on the forum and guess at it.

Please don't make assumptions.

My PE table is 1.22 regardless of fuel burned, Lambda 1/1.22 = .82 I don't really care what the AFR is.

My stoich table is set to the appropriate AFR for the fuel burned or Flex fuel sensor.

My VE and MAF are tune to achieve commanded Lambda both in closed and open loop.

You have to stop trying to use formulas to convert AFR to Lambda.

We use Lambda, as it is the same across all stoich values.

You only need to know the Stoich value of the fuel at the beginning of creation of the tune and should obtain that from the fuel manufacturer.

After that its all Lambda.

Like I said just because your commanding .90 lambda does not mean your running .90 the end result is derived from the MAF calibration and will show up on your gauge.

If your car is showing .90 lambda at WOT STOP IMMEDIATELY.

[JANNETTYRACING]

Originally Posted by IneedAZ

Totally agree...Just been waiting til this coming sunday as i just finished cleaning it up for a car show..Maybe on the way home weather permitting i can do a wot test. And yes, that is why i wanted to know if Ted was using 14.7 or 14.1.

Again, appreciate everybody posting

Set your Gauge to LAMBDA, it is in the settings.

[IneedAZ]

Originally Posted by JANNETTYRACING

Set your Gauge to LAMBDA, it is in the settings.

I believe it is but will double check. It is an Aeroforce intercepter gauge and wideband setup.