MHD Flex Fuel Kit, mixing E85 with 91oct B58

nrg2k · 10-29-2023, 10:34 AM

Hey forums,

I live in AZ, we have pretty poor fuel to choose from out here. Highest pump gas is 91oct, sometimes you can find 100oct. I want to start running E40 as I got the TU Pump for my F22 240. I’ve been considering buying the MHD Flex Fuel kit for the convenience factor, but if I remember right I seen a Kern417 video where he mentioned the kit doesn’t read 91 Oct. Is that still true? Would I just limited to Stage 2, and not stage 2+ because I can’t mix the E85 with 93?

Also, if I were to throw 100oct in the car, would the MHD Stage 2+ 95oct OTS tune be safe for the fuel I am running?

n55david · 10-29-2023, 07:18 PM

Quote:

Originally Posted by nrg2k

Hey forums,

I live in AZ, we have pretty poor fuel to choose from out here. Highest pump gas is 91oct, sometimes you can find 100oct. I want to start running E40 as I got the TU Pump for my F22 240. I’ve been considering buying the MHD Flex Fuel kit for the convenience factor, but if I remember right I seen a Kern417 video where he mentioned the kit doesn’t read 91 Oct. Is that still true? Would I just limited to Stage 2, and not stage 2+ because I can’t mix the E85 with 93?

Also, if I were to throw 100oct in the car, would the MHD Stage 2+ 95oct OTS tune be safe for the fuel I am running?

You can mix e85 with your garbage 89 (fake 91).. you just have to use more e85 to compensate.. you'll wanna run about e45 to run the e40 mhd map.

marcthedark · 10-31-2023, 06:49 AM

Quote:

Originally Posted by n55david

You can mix e85 with your garbage 89 (fake 91).. you just have to use more e85 to compensate.. you'll wanna run about e45 to run the e40 mhd map.

But the OP wanted to use the flex fuel kit. That obviously measures E in the tank but not if the rest is 93 or crappy 91 > will the timing be OK as the Arizona 91 might lead to pull

SpencerC_6MT · 11-01-2023, 11:58 PM

I've ran E30 on my stock tune (with a boost controller) just to make the 93 setting run smooth. I'm tempted to suggest you just run an aggressive 93 tune on E40 and go back to a 91 tune when you can't get your hands on E85.

cooolone2 · 03-17-2024, 09:09 AM

Could order a 55gal drum of Race Gas (Sunoco) and mix that too... Proper ratios to obtain a 95 even or higher if racing and want max benefit (with tune). Lol

dradernh · 03-17-2024, 07:41 PM

Quote:

Originally Posted by cooolone2

Could order a 55gal drum of Race Gas (Sunoco) and mix that too... Proper ratios to obtain a 95 even or higher if racing and want max benefit (with tune). Lol

I carried a 55-gallon drum of Sunoco leaded 116 octane when I ran an autocross car tuned for it. Nothing to it, really, when you have a pickup and are towing the car.

marcthedark · 03-19-2024, 10:58 AM

MHD released a 2plus 91 map > so you can use 91 and MHD should adjust accordingly when you add E

Dantesboyz · 03-27-2024, 01:07 PM

Use a couple ounces of boostane to correct the unleaded then add the ethanol to E target.

That's my fix when I suspect bad octane in the fuel.

I use this app (android) when calculating Emix
https://play.google.com/store/apps/d...anolCalculator

And I also have an Ethanol Content Analyzer.
In the F22, I get the most accurate mix by calculating the tank to be 12.8 gallons instead of 13.

10-29-2023, 10:34 AM	#1
nrg2k Nrg2k 75 Rep 3 Posts Drives: 2018 F22 ZF M240i Join Date: Jun 2023 Location: Arizona iTrader: (0) Garage List 2018 BMW M240i [9.75]	Hey forums, I live in AZ, we have pretty poor fuel to choose from out here. Highest pump gas is 91oct, sometimes you can find 100oct. I want to start running E40 as I got the TU Pump for my F22 240. I’ve been considering buying the MHD Flex Fuel kit for the convenience factor, but if I remember right I seen a Kern417 video where he mentioned the kit doesn’t read 91 Oct. Is that still true? Would I just limited to Stage 2, and not stage 2+ because I can’t mix the E85 with 93? Also, if I were to throw 100oct in the car, would the MHD Stage 2+ 95oct OTS tune be safe for the fuel I am running?
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11-01-2023, 11:58 PM	#4
SpencerC_6MT Second Lieutenant 201 Rep 240 Posts Drives: '17 M240i 6MT Join Date: May 2017 Location: San Diego, CA /// Tuscaloosa, AL iTrader: (0) Garage List 2017 BMW M240I [0.00]	I've ran E30 on my stock tune (with a boost controller) just to make the 93 setting run smooth. I'm tempted to suggest you just run an aggressive 93 tune on E40 and go back to a 91 tune when you can't get your hands on E85. __________________ 2017 BMW M240i 6MT Slicktop \| Wavetrac 3.46:1 Limited-Slip Diff - DinanTRONICS Sport Boost Controller - H&R Sport Springs - Millway Street Camber Plates - Agency Power Intake w/ Paradigm Engineering Turbo Inlet
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03-17-2024, 09:09 AM	#5
cooolone2 Captain 668 Rep 745 Posts Drives: 20' M240iX B58, 01' 330XI E46 Join Date: Jul 2019 Location: NY, USA iTrader: (0)	Could order a 55gal drum of Race Gas (Sunoco) and mix that too... Proper ratios to obtain a 95 even or higher if racing and want max benefit (with tune). Lol
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03-19-2024, 10:58 AM	#7
marcthedark Lieutenant 126 Rep 413 Posts Drives: M240i xdrive Convertible Join Date: Apr 2017 Location: Phoenix Metro Area iTrader: (0)	MHD released a 2plus 91 map > so you can use 91 and MHD should adjust accordingly when you add E
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03-27-2024, 01:07 PM	#8
Dantesboyz recovering e36er 89 Rep 133 Posts Drives: 2017 M240i Xdrive Join Date: Nov 2017 Location: Johnstown OH iTrader: (0) Garage List [10.00] 2017 ///M240i XDrive [7.25]	Use a couple ounces of boostane to correct the unleaded then add the ethanol to E target. That's my fix when I suspect bad octane in the fuel. I use this app (android) when calculating Emix https://play.google.com/store/apps/d...anolCalculator And I also have an Ethanol Content Analyzer. In the F22, I get the most accurate mix by calculating the tank to be 12.8 gallons instead of 13. __________________ 2017 F22 M240i, Xdrive, M Performance Package Active Autowerke Downpipe, Dinan Carbon Fiber Intake, Dinan Carbon Fiber Turbo Inlet, Dinan Mid-pipe, xHP Flashtool, MHD Stage 2 To do next list- #1- Wheel Spacers & Tires, #2- B58 TU Pump, #3- Flex Fuel Kit
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