EQ Ratio vs MAF Please Look Over Tune File and Scans

[LSandlteditor]

Hey Guys,

I Believe I figured out how to use this New AEM 30-0334 OBDII Wideband with an EQ Ratio Error Graph. Please look over my scan Files and Tune File and Tell me if the Slight Fluctuation im seeing is perfectly fine or not, i believe it is but Im not 100% Sure. I'm new to Lambda, i set my EQ Ratio to 1.174 Which on 100% Pump Gas would be 12.5 AFR, and that equates to .85 LAMBDA. I'm using EQ RATIO ERROR MATH vs MAF FREQUENCY SENSOR to correct by Multiplying by % Half. Also, i set my Wideband to Read Lambda as I am trying to Learn Lambda. So i'm running a Flex Fuel Tune with a Flex Fuel Sensor Mounted on the Fuel Rail. Currently I have 11.0-11.4% Ethanol in the tank, The Rest is 91 Octane. I know with 11% Being in the Tank my Commanded Stoich is Around 13.95 - 14.04 AFR. NOW Heres the part that gets me.....I know that 14.04 Stoich DIVIDED BY MY PE EQ RATIO OF 1.174 = 11.9 AFR Do I ignore all that if i'm targeting Lambda Now? Is being at .85 Lambda Perfectly Fine for whatever Fuel i'm using On My Naturally Aspirated Cammed Truck? Do I ignore Stoich Now Due to Using Lambda? I know stoich is always 1.00 when using Lambda, so it won't matter what fuel i'm using correct? However the transition from AFRS to Lambda on Flex Fuel is a Bear for me at the moment. Attached I Have 2 Scan Files along with my Tune File. Both Scans are from the same exact tune except 2 different occasions i went WOT in Second Gear at 3000RPM. Please Feel Free to correct me and give pointers. THANK YOU!!!!!

Here are my Mods
2011 Gen IV E38 Chevy Avalanche 5.3l With 6l80e
BTR Stage 3 Cam 218/224 113 LSA
Longtube Headers
Cold air Intake with GREEN FILTER
FLEX FUEL SENSOR at the RAIL


Golden New GREEN 91 - e85- dialed in WOT New Part and idle BEST YET.hpt
AFR SHOW THE FORUM.hpl
AFR SHOW FORUM 2.hpl


THANKS TO ANYONE WILLING TO HELP!!!

[RobZL1]

I haven't looked at the logs yet, but in short, you are correct. Target lambda will be the same, regardless of the blend in your tank. 0.85 lambda will be your WOT target, period. 1.00 will be your stoich/cruise target, regardless.

[LSandlteditor]

Well i'm going to update everyone as this can help someone in the future who is learning Lambda and WOT Tuning or AFR Tuning for that matter. So after speaking with ERM Performance, I explained to him what was going on and if my process was practical and made sense. He clarified a couple of my questions as stated earlier about lambda and my thought process in the Original Post was correct. I however noticed that when I Tune For WOT in SECOND Gear and get it dialed in, the Commanded and ACTUAL EQ RATIO are perfect for SECOND gear, however at a higher gear Like THIRD or FOURTH it goes Richer by up to .4-.5 in some cases. So, say one is commanding .85 Lambda and tuned for getting .85 Lambda in SECOND gear, then at a higher load you will be Richer.

After speaking with Ed from ERM, he mentioned to me wanting to be at ideally a 1.1 Transmission ratio and then tune for WOT. So I decided to try again tonight with retuning the MAF for WOT using EQ Ratio but this time in FOURTH Gear. Now, im still commanding .85 lambda, however this time i'm using the Scanner Values while being in a Higher Gear, more load. I calibrated the MAF for WOT in FOURTH Gear and Got it Perfect.... NOW HERE is the KICKER....I thought to myself, let me go ahead and do a 2nd gear pull from 3,000 RPM up and See how the Wideband Reading looks....I do a pull in SECOND GEAR after Tuning for WOT in FOURTH and now SECOND GEAR is slightly leaner than my Commanded Lambda of .85....in Second gear it goes .3-.4 Leaner highest I saw was .88


This was all done on the street and I manipulated my transmission table shift MPH Tables so that I can Use FOurth Gear without it downshifting. Hope this helps someone. Experienced Tuners and Vets, please Chime in.

[LSandlteditor]

Would love some feedback. It would be much appreciated.

[RobZL1]

It has to do with transients and loading. The manifold temp, cylinder temp, rate of RPM increase, and X-tau (fuel puddle on the port walls) all contribute. Some people tune in 3rd gear because of this, so that it balances out. I have heard of hardcore drag racers actually tuning for 1st-3rd for better 1/8 mile performance and more biased toward 4th for 1/4 mile runs (and their 1/8 performance actually suffers while the 1/4 improves). For reference, my car runs 0.78 in 4th, 0.79 in 3rd, and 0.80 in 2nd.

[LSandlteditor]

It has to do with transients and loading. The manifold temp, cylinder temp, rate of RPM increase, and X-tau (fuel puddle on the port walls) all contribute. Some people tune in 3rd gear because of this, so that it balances out. I have heard of hardcore drag racers actually tuning for 1st-3rd for better 1/8 mile performance and more biased toward 4th for 1/4 mile runs (and their 1/8 performance actually suffers while the 1/4 improves). For reference, my car runs 0.78 in 4th, 0.79 in 3rd, and 0.80 in 2nd.

But I have heard that you must be in a 1.1 transmission ratio. The 6l80e does not have one, closest one being 4th gear. That is why I tuned for fourth gear.

[5FDP]

I use 2nd, 3rd or 4th depending on what I'm doing and where I am doing it. Speed limits and certain roads only allows me to do so much.

I get it close, you can never be exact on the street because of variables. If I can get it within 2-3% of my target all the time and it's not doing anything crazy I just let it ride. It's exact why I run a little richer instead of on the edge. Why run say 12.8 when I can run 12.2-12.3 commanded AFR and always be safe and have plenty of torque.

[RobZL1]

But I have heard that you must be in a 1.1 transmission ratio. The 6l80e does not have one, closest one being 4th gear. That is why I tuned for fourth gear.

Ratio really doesn't matter, in my opinion. 3rd or 4th makes sense in your case, I think.

I use 2nd, 3rd or 4th depending on what I'm doing and where I am doing it. Speed limits and certain roads only allows me to do so much.

I get it close, you can never be exact on the street because of variables. If I can get it within 2-3% of my target all the time and it's not doing anything crazy I just let it ride. It's exact why I run a little richer instead of on the edge. Why run say 12.8 when I can run 12.2-12.3 commanded AFR and always be safe and have plenty of torque.

I'm of the same thinking.