Question for the Tuned (Non Meth) folks

IneedAZ · 08-30-2021, 01:25 PM

What AFR or Lamda did you or your tuner set as a desired number? From what i have read the LT4 can run leaner than previous motors being it is direct injected. My latest tune showed me to be around 13.1 AFR. Previous tuner had me in the mid 12 range i believe. I will need to pull an old log to verify.

CW3SF · 08-30-2021, 02:53 PM

I believe target is around 12.3-12.4 at WOT on flex fuel car.

IneedAZ · 08-30-2021, 03:27 PM

Quote:

Originally Posted by CW3SF

I believe target is around 12.3-12.4 at WOT on flex fuel car.

what about non flex fuel? Like to know both!

*radz28* · 08-30-2021, 04:50 PM

Safe EQ for DI FI is something like .80-.85 or so. If you're using 14.108 as stoich, that's a range of about 11.286 to about 12.0 I believe. Lean is meaner, is what's said, but you could probably go as high as you are if your are running 93-plus octane booster, which I thought I remembered you saying. I imagine fuel where you are is probably okay to do that. I couldn't do that here, with the 91-swill we have. I think I've seen about .83-.84 on 91-plus octane booster (blended to about 93-94 octane).

You can't run too rich, otherwise you'll get knock with DI. DI is more efficient than port, so you can run leaner.

Camaro1973 · 08-30-2021, 06:59 PM

Quote:

Originally Posted by IneedAZ

What AFR or Lamda did you or your tuner set as a desired number? From what i have read the LT4 can run leaner than previous motors being it is direct injected. My latest tune showed me to be around 13.1 AFR. Previous tuner had me in the mid 12 range i believe. I will need to pull an old log to verify.

13.1 AFR on a wideband at WOT? That's way lean.

I've seen average 11.9-12.5 WOT.

My commanded is 12, don't have a wideband for exact.

Stephen12ZL1 · 08-30-2021, 07:23 PM

At 40% E my AEM gauge was reading 11.2 AFR at WOT on a long pull. It is probably 11.8 with only 93 octane in the same situation.

Joshinator99 · 08-30-2021, 09:01 PM

Quote:

Originally Posted by Camaro1973

13.1 AFR on a wideband at WOT? That's way lean.

I've seen average 11.9-12.5 WOT.

My commanded is 12, don't have a wideband for exact.

Agreed. Target of .82 lambda is a good number for FI/DI engines.

IneedAZ · 08-31-2021, 05:51 AM

Quote:

Originally Posted by Camaro1973

13.1 AFR on a wideband at WOT? That's way lean.

I don't have the logs he used on the dyno so I don't know what my wideband reading was. I'm going by the sensor he stuck in the muffler connected to the dyno. I could be wrong but would think his sensor being that it is much further back would show a leaner number than mine, but could be wrong.

IneedAZ · 08-31-2021, 07:07 AM

Something i can check without the logs is the PE to see what i am commanding and compare that to others

KingLT1 · 08-31-2021, 08:55 AM

.80-.82 Lambda is what you should be targeting with FI on E. 93 octane I would go a touch richer. I would only do .84 to stretch out the fuel system if the injector pusle widths are getting too high or pressure is dropping. Anything higher then .85 is too lean.

Comparing PE from one car to the next doesn't mean much because the VVE and MAF may not be tuned to target what the PE number is suppose to be hitting. I have seen plenty of tunes where the PE is the same but the Wideband is reading different.

Either way I use PE multiplier of 1.205.

14.7 / 1.205 = 12.199 AFR target. You use 14.7 if trying to calculate AFR on a gas scale not 14.06 which is E10.

IneedAZ · 08-31-2021, 09:25 AM

Quote:

Originally Posted by KingLT1

.80-.82 Lambda is what you should be targeting with FI on E. 93 octane I would go a touch richer. I would only do .84 to stretch out the fuel system if the injector pusle widths are getting too high or pressure is dropping. Anything higher then .85 is too lean.

Comparing PE from one car to the next doesn't mean much because the VVE and MAF may not be tuned to target what the PE number is suppose to be hitting. I have seen plenty of tunes where the PE is the same but the Wideband is reading different.

Either way I use PE multiplier of 1.205.

14.7 / 1.205 = 12.199 AFR target. You use 14.7 if trying to calculate AFR on a gas scale not 14.06 which is E10.

how much diff u think there is from my wideband to his sensor back at the muffler? Would u think his would show a little leaner?

KingLT1 · 08-31-2021, 09:59 AM

At idle maybe...at WOT I doubt it.

IneedAZ · 08-31-2021, 12:14 PM

Quote:

Originally Posted by KingLT1

At idle maybe...at WOT I doubt it.

Guess i will check my PE table..see what he is commanding and see how close it is to actual and then i can adjust the MAF as needed. I may be adding e to the car next week. I am not really doing for the power gains, but more so for the cooling benefits and will quit using the Boostane. I believe it will be a good tradeoff.. Get similar octane, but added cooling. Probably shoot for e30 or e40. I don't need to push it since not doing it for big number gains.

KingLT1 · 08-31-2021, 03:35 PM

Make sure to look up the stoichiometric value in your stoich table and divide the PE multiplier into AFR like shown above.

On my car I use 14.7 because that is the stoich value used in the 0% E cell. From the factory GM uses 14.06 across all cells so if that value is in the 0% cell then that is what you use. Mine is tuned on E so all the Ethanol % cells are populated with the correct stoich value.

08-30-2021, 01:25 PM	#1
IneedAZ Drives: 2017 ZL1 A10 & 2021 BMW M340i x Dr Join Date: Mar 2009 Location: Tampa Posts: 5,110 View My Garage	Question for the Tuned (Non Meth) folks What AFR or Lamda did you or your tuner set as a desired number? From what i have read the LT4 can run leaner than previous motors being it is direct injected. My latest tune showed me to be around 13.1 AFR. Previous tuner had me in the mid 12 range i believe. I will need to pull an old log to verify. __________________ Sold 2012 2LT RS 12.3@112 old setup Sold 1967 Camaro Pro Street. Ran 10's mild BB on NOS. 2017 HyperBlue ZL1 A10 Born 3/17/17Delivered 4/08/17 2020 Build: Mag2650, BTR Stage2, NW103, BG, 14% lower, 90mm upper, ARH 2" Long system w/no cats, SW Legend mufflers. 807hp/762tq on 93 gas and 848hp/792tq on e47 Sold 2018 (Go Mango) Dodge Charger Daytona 392 Daily Driver Daily Driver 2021 BMW M340i Xdrive

08-30-2021, 02:53 PM	#2
CW3SF Drives: 2019 Chevy Camaro ZL1 M6 Join Date: Jul 2019 Location: Sea level Posts: 1,252 View My Garage	I believe target is around 12.3-12.4 at WOT on flex fuel car. __________________ Kong Stage X Port, NW103, LPE HPFP, XDI +30 Injectors, ARH Headers, Flex Fuel, JMS Booster, AWE Touring, Elite E2-X CC. Stock heads, stock cam, stock pulleys: Tuned by KingLT1. 740whp Uncorrected on e50

08-30-2021, 04:50 PM	#4
radz28 Petro-sexual Drives: Ultra-Grin Join Date: Oct 2006 Location: Crazy Coast Posts: 15,192 View My Garage	Safe EQ for DI FI is something like .80-.85 or so. If you're using 14.108 as stoich, that's a range of about 11.286 to about 12.0 I believe. Lean is meaner, is what's said, but you could probably go as high as you are if your are running 93-plus octane booster, which I thought I remembered you saying. I imagine fuel where you are is probably okay to do that. I couldn't do that here, with the 91-swill we have. I think I've seen about .83-.84 on 91-plus octane booster (blended to about 93-94 octane). You can't run too rich, otherwise you'll get knock with DI. DI is more efficient than port, so you can run leaner. __________________ '20 ZL1 Black "Fury" A10, PDR, Exposed CF Extractor Magnuson Magnum DI TVS2650R // RFBG // Soler 103 // TooHighPSI Port Injection // THPSI Billet Lid // FF // Katech Drop-In // PLM Heat Exchanger // ZLE Cradle bushings // BMR Chassis-Suspension Stuff // aFe Bars // Diode Dynamics LEDs // ACS Composites Guards // CF Dash // Aeroforce // tint // other stuffs

08-30-2021, 07:23 PM	#6
Stephen12ZL1 Drives: '21 ZLE A10 Join Date: May 2012 Location: Mechanicsville, VA Posts: 6,808	At 40% E my AEM gauge was reading 11.2 AFR at WOT on a long pull. It is probably 11.8 with only 93 octane in the same situation. __________________ '21 ZLE A10 Wild Cherry PDR 2:00.78 VIR Full 10.68@131.69 1.68 60' '17 ZL1 A10 Mosaic Black PDR/Nav 2:03.08 VIR Full 11.003@129.2 1.75 (sold) '15 Z/28 #325 Black a/c & stereo. 2:10.1 VIR Full (sold) '12 ZL1 A6 Black 10.52@131 1.55 60' 2:13 VIR Full (sold)

08-31-2021, 07:07 AM	#9
IneedAZ Drives: 2017 ZL1 A10 & 2021 BMW M340i x Dr Join Date: Mar 2009 Location: Tampa Posts: 5,110 View My Garage	Something i can check without the logs is the PE to see what i am commanding and compare that to others __________________ Sold 2012 2LT RS 12.3@112 old setup Sold 1967 Camaro Pro Street. Ran 10's mild BB on NOS. 2017 HyperBlue ZL1 A10 Born 3/17/17Delivered 4/08/17 2020 Build: Mag2650, BTR Stage2, NW103, BG, 14% lower, 90mm upper, ARH 2" Long system w/no cats, SW Legend mufflers. 807hp/762tq on 93 gas and 848hp/792tq on e47 Sold 2018 (Go Mango) Dodge Charger Daytona 392 Daily Driver Daily Driver 2021 BMW M340i Xdrive

08-31-2021, 08:55 AM	#10
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,796	.80-.82 Lambda is what you should be targeting with FI on E. 93 octane I would go a touch richer. I would only do .84 to stretch out the fuel system if the injector pusle widths are getting too high or pressure is dropping. Anything higher then .85 is too lean. Comparing PE from one car to the next doesn't mean much because the VVE and MAF may not be tuned to target what the PE number is suppose to be hitting. I have seen plenty of tunes where the PE is the same but the Wideband is reading different. Either way I use PE multiplier of 1.205. 14.7 / 1.205 = 12.199 AFR target. You use 14.7 if trying to calculate AFR on a gas scale not 14.06 which is E10. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

08-31-2021, 09:59 AM	#12
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,796	At idle maybe...at WOT I doubt it. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

08-31-2021, 03:35 PM	#14
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,796	Make sure to look up the stoichiometric value in your stoich table and divide the PE multiplier into AFR like shown above. On my car I use 14.7 because that is the stoich value used in the 0% E cell. From the factory GM uses 14.06 across all cells so if that value is in the 0% cell then that is what you use. Mine is tuned on E so all the Ethanol % cells are populated with the correct stoich value. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

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