[Slim415]

Im about to get an MHD tune and a Galaxy tablet to run it with along with a few other mods to install at the same time. I know I will be leaving power on the table if I run 91 octane but I would have to drive 30 minutes to get to the closest station that sells 93. And 40 minutes for e85. So this is a 3 part question.

1- Would my tune be able to tell what gas I'm using if I change from 91 to 93 or e85? Or would I have to manually change maps?

2- What if I still have 1/4 tank of 91 and I want to fill up with 93 or e85? Or go down from 93 to 91.

3- Will MHD have different octanes for me in the same map? Or will it require different purchases of separate maps?

Thanks guys!

[E93Beast]

Originally Posted by Slim415

Im about to get an MHD tune and a Galaxy tablet to run it with along with a few other mods to install at the same time. I know I will be leaving power on the table if I run 91 octane but I would have to drive 30 minutes to get to the closest station that sells 93. And 40 minutes for e85. So this is a 3 part question.

1- Would my tune be able to tell what gas I'm using if I change from 91 to 93 or e85? Or would I have to manually change maps?

2- What if I still have 1/4 tank of 91 and I want to fill up with 93 or e85? Or go down from 93 to 91.

3- Will MHD have different octanes for me in the same map? Or will it require different purchases of separate maps?

Thanks guys!

1. I dont run MHD , but manually change maps most likely.
2. Just mix them, no harm, but E85 requires a different map all together.
3. Most likely different maps, especially running E85 as it will run leaner and cause fuel trims to climb.
Scalars must be changed in the flash to run higher concentrations or full E85.

[mkolankowski]

If you get the Motiv flex fuel kit theres no changing maps. Just have to set your pump gas map and whenever you add e85 it automatically adjusts the tables for the ethanol.

[Bimmer_Engineer]

MHD has multiple maps on each stage for different fuel types. If the map you're running is too aggressive then it will pull timing, just like the car does with the OE map. I was running the 93 octane map, and running 93 octane fuel but my car doesn't like that map with the 93 octane fuel we have here...so I backed down to the 91 octane map and it pulls hard with no timing reductions...

[alpnwss]

1) You should read the MHD Manual cover to cover
2) It takes maybe 1.5m to change maps. Just be very careful about clicking and slow down. It's not hard to hit the wrong thing etc.
2.5) Remember there is fuel in the lines and injectors, so when you switch fuels, remember that it takes a minute to get it all flushed.

[Slim415]

Ok, and I'm a bit confused with the MHD website. Do I buy anything from the site or does anything get shipped to me? Or do I just buy the app and go from there? What's the difference between the flasher module and monitor module? Are those handheld devices? I'm just having trouble finding anywhere on the website to purchase anything.

[IllSic_Design]

You download the MHD APP to your cell phone/tablet. You purchase the tunes/flasher module from MHD through the app. You need the flasher module and then the map packs at least to tune your car. The "Monitor Module" is a set of gauges on the MHD app that you can use to monitor the car while driving/tuning/whatever, purchased separately from the other 2 items.

Nothing gets shipped to you, you use your cell phone to purchase the app and maps/flasher. You do need to have/buy a DCAN cable and an OTG cable for your phone to be able to connect it to your car and flash the tunes.

[langsbr]

Originally Posted by Slim415

1- Would my tune be able to tell what gas I'm using if I change from 91 to 93 or e85? Or would I have to manually change maps?

No. If just using the OTS stage maps, it presumes you put in the proper octane fuel. You would need to get the Motiv/MHD Flex fuel to let it autodetect ethanol, but if running pump gas, you'd sitll need to specify proper octane.

Originally Posted by Slim415

2- What if I still have 1/4 tank of 91 and I want to fill up with 93 or e85? Or go down from 93 to 91.

If you're running the OTS maps, say the 91 octane map, and you then fill up with 93 or E85, you would need to flash the corresponding map.

Originally Posted by Slim415

3- Will MHD have different octanes for me in the same map? Or will it require different purchases of separate maps?

Not in the same "map" but in the same Stage. There are various octanes for each stage if you purchase the OTS "map pack".

[IllSic_Design]

Originally Posted by langsbr

You would need to get the Motiv/MHD Flex fuel to let it autodetect ethanol, but if running pump gas, you'd sitll need to specify proper octane.

Might have misunderstood what you said, but that's incorrect. If you have Motiv flex fuel, there is NEVER a need to change the octane of the tune. Even if running straight gas, the tune will correct for that mix. I have been on regular ACN91 Stage 2+ since flex fuel came out and never need to switch maps, I run anywhere from 91 to E50.

[langsbr]

Originally Posted by IllSic_Design

Might have misunderstood what you said, but that's incorrect. If you have Motiv flex fuel, there is NEVER a need to change the octane of the tune. Even if running straight gas, the tune will correct for that mix. I have been on regular ACN91 Stage 2+ since flex fuel came out and never need to switch maps, I run anywhere from 91 to E50.

No - you are correct that you can run any variance of ETHANOL. But the Flex fuel kit does NOTHING for determining 91 or 93.

Your base tune is on ACN91 (which is pretty much worse than 89) and then you have flex fuel which accomodates adding ethanol for additional octane.

If you fill up with 93, you will get no additional benefit over your ACN91 tune (other than knock resistance) but it will not increase timing/boost/fueling because there is no extra ethanol.

There are some lab sensors that can determine octane, but they cost many thousands of dollars vs and $80 ethanol sensor which just measures capacitance.

[mweisdorfer]

Originally Posted by Slim415

Im about to get an MHD tune and a Galaxy tablet to run it with along with a few other mods to install at the same time. I know I will be leaving power on the table if I run 91 octane but I would have to drive 30 minutes to get to the closest station that sells 93. And 40 minutes for e85. So this is a 3 part question.

1- Would my tune be able to tell what gas I'm using if I change from 91 to 93 or e85? Or would I have to manually change maps?

2- What if I still have 1/4 tank of 91 and I want to fill up with 93 or e85? Or go down from 93 to 91.

3- Will MHD have different octanes for me in the same map? Or will it require different purchases of separate maps?

Thanks guys!

1- Would my tune be able to tell what gas I'm using if I change from 91 to 93 or e85? Or would I have to manually change maps?

No. You would have to change the map via tablet.

2- What if I still have 1/4 tank of 91 and I want to fill up with 93 or e85? Or go down from 93 to 91.

I wouldn't worry about going from 91 to 93. It's insignificant.

You should get an E85 app to help you figure out the mixing ratios for E85. You can always buy a 5 gallon gas can and fill it up with E85. On an 1/8 tank of gas using all 5 gallons of E85 and filling the rest with 93, you'd be pretty close to E30 - so, you'd have to flash to an E30 map before you pull out of the gas station.

3- Will MHD have different octanes for me in the same map? Or will it require different purchases of separate maps?

Yes, you will have different octanes in the same map.

[langsbr]

Originally Posted by mweisdorfer

Yes, you will have different octanes in the same map.

This is not true, or it's confusing MAPS with STAGES.

If you load a Stage 1 MAP for 93 octane, it assumes you are ALWAYS using 93 octane. If you want to use 91 (especially piss water ACN91) you should flash to the Stage 1 MAP for 91.

Same for stage 2 - each MAP you load assumes you are using the fuel that corresponds for what you loaded, e.g. 91 octane for 91 MAP, 93 for 93 MAP.

[IllSic_Design]

Originally Posted by langsbr

No - you are correct that you can run any variance of ETHANOL. But the Flex fuel kit does NOTHING for determining 91 or 93.

Your base tune is on ACN91 (which is pretty much worse than 89) and then you have flex fuel which accomodates adding ethanol for additional octane.

If you fill up with 93, you will get no additional benefit over your ACN91 tune (other than knock resistance) but it will not increase timing/boost/fueling because there is no extra ethanol.

There are some lab sensors that can determine octane, but they cost many thousands of dollars vs and $80 ethanol sensor which just measures capacitance.

Ok yeah you're right on that, I wasn't thinking about the different maps for 91/93, etc. I was thinking about it in a different way, my fault. I run the lowest quality tune for the lowest quality gas, so all I can get really is 91 so I don't have to worry about running a 93oct map and then getting 91 oct gas.

[mweisdorfer]

Originally Posted by langsbr

This is not true, or it's confusing MAPS with STAGES.

If you load a Stage 1 MAP for 93 octane, it assumes you are ALWAYS using 93 octane. If you want to use 91 (especially piss water ACN91) you should flash to the Stage 1 MAP for 91.

Same for stage 2 - each MAP you load assumes you are using the fuel that corresponds for what you loaded, e.g. 91 octane for 91 MAP, 93 for 93 MAP.

That's what I meant. You have different octane(s) I'm the same map. So, you don't have to purchase each map separately based on Octane level

[coppee]

If I run the wrong Map/Fuel combo (say Stage2+ 91 map with ACN91 fuel) what happens? Will this hurt the engine? Will I get a performance difference?

[Saif2018]

Originally Posted by coppee

If I run the wrong Map/Fuel combo (say Stage2+ 91 map with ACN91 fuel) what happens? Will this hurt the engine? Will I get a performance difference?

I doubt it will hurt the engine but running 91oct map with ACN91 fuel will most likely result in several timing corrections and loss of some performance.

Use the correct Octane map for the fuel your using.

[lookalikehuuh]

Originally Posted by coppee

If I run the wrong Map/Fuel combo (say Stage2+ 91 map with ACN91 fuel) what happens? Will this hurt the engine? Will I get a performance difference?

I accidentally ran 91 tune on ACN91 fuel before with no real issues. There were timing corrections all over the place which of course means less power in the end. There is inherently some higher risk of pre-detonation by running a tune that is designed for higher octane fuels than what you are actually using.

With that in mind why not just use the ACN91 tune and not risk some pre-detonation?