MHD FlexFuel Adapter (5 Minutes to FlexFuel)

[slaughter.mode]

I was running BM3 Stage 2 (ACN91) for the last year or so and it's been great and all but I wanted to try E85 AND I wanted an easy flex fuel option so I decided to give this CAN FlexFuel Analyzer a shot which also means trying out MHD tuning software.

Update 7/13/21:
Just picked up the MHD CAN ECA PnP unit, didn't realize they're also in SoCal! Grabbed a OBDII WiFi interface as well. It's as fast as my OBDII lightning adapter without any wires:




Update 7/13/21:
Installed the MHD CAN ECA unit. Super easy. Re-flashed the MHD Stage 2+ E30 map to include that I have their ethanol analyzer and voila! (My guesstimated E30 mix I did last night wasn't too far off! reads 29-30%!)



Update 7/13/21:
I was not sure why the rolling anti-lag wasn't working (I am very used to it from BM3's version and apparently their video on YouTube is incorrectly stating to use the 'SET' button but I got a e-mail from MHD saying it's supposed to be the 'RES' button. Just a FYI for those wondering why it's not working.

Update 8/13/2021
MHD just released version 3.4.0:

• Flex support for their MHD ECA (which I had installed previously).
• Multimap function
• S1 & S2 E85 OTS Maps

Update 8/18/2021:
I decided to give my tuner a breather as we're running into some misfiring issues at the upper RPM range and give this MHD OTS Flex tune a try. I'm pretty damn impressed. The PSI is a bit on the low side 18-19PSI (I need to log it to validate for sure) but it is everything you'd expect from a mature OTS map. Idles smooth, starts smooth, and more than likely long term durable.

What's cool:
Their flex option works with multiple CAN ECA sensors, doesn't even have to be MHD's option from Bimecu. I can't stress how great this is for a OTS feature. Nobody else does this.

What's not so cool:
I do wish they allowed you to apply the Flex option to any of their OTS maps without having to use the multimap option but that's the way it's setup right now. So, since I care less about having multiple maps, I just placed the same map in all 4 slots.

Definitely read the manual but the way it works (if you want Flex) is you need to select 4 OTS maps for each 4 slots and not a single one of them can be a E-map (i.e. their S2 E85 map or the S2+ E30 map). Has to be normal fuel maps only. The Flex option then takes into account the levels of ethanol you have in your tank and modifies the fuel map you have accordingly based on Stage you selected, etc. It's quite robust.

[RElias21]

Originally Posted by the_ghost

I was running BM3 Stage 2 91 for the last year or so and it's been great and all but I wanted to try corn power AND I wanted a reasonable flex fuel option so I decided I'm going to try out this CAN FlexFuel Analyzer which also means trying out MHD. The MHD super license comes with a ton of OTA tunes for only ~$500. No brainer-sold.

I am going to have this professionally tuned but I need to address this ridiculous out of the box experience.

First I flashed my 2018 M4 Competition to the S2+ 91 tune. I read it's the equivalent of the BM3 S2 91 tune. No way. Already it crushed my BM3 S2 tune in terms of butt dyno (but my logs and meter read 4-6 more PSI). It's a reasonable assumption it is faster...but then I got greedy. I remember I also have access to a S2+ E30 map and oh, how convenient, I'm passing a 76 fuel station which has E85.

I had to do it.

I put in 4.4gal of E85 and the rest 91 (all we have in SoCal). I flashed it in about 8 seconds and fired it up. Now before you try to yell at me, I know from others the ethanol content is generally 79-82% at this station, consistently.

Anyway, I drive up a hill and down at a moderate rate so the 91 and E85 can blend up. Next, I need to give it a pull. I found a freeway onramp and...yo... I have never spun 4th gear before. I'm not talking about a little hop + chirp, I'm talking my whole ass wanted to be in another lane, while climbing the MPHs like a demon from hell. I'm running 30psi 305x30x20 Michelin PS4s and they were over 100 degrees. I run stock camber, this car is planted. This thing suddenly has anger issues.

I have about 150k miles of combined F8X miles on the same roads. I believe my butt dyno-ism methodology is somewhat qualified when I say this is really the most insane tune I ever purchased over the air. I am a huge BM3 advocate too.

tl;dr-If you are the average M-thusiast and are just looking to squeeze some major ponies out of your car without spending a ton of money on tuning---definitely go with MHD! -A BM3 fanboy.

This is interesting.

With respect to the OTS Stg. 2 setup, it sounds to me like you are saying that MHD stage 2 runs a few psi higher than BM3 stage 2?

Also, with respect to E85, did you ever compare it to the BM3 E85 maps? Otherwise, are you comparing apples to apples?

Lastly, for current BM3 owners, would you recommend MHD OR custom tuning via BM3?

Thanks.

[E92Roni]

I've been using MHD on several different BMWs (E and F) chassis. Never had issues, only smiles. Simple to use, convenient app that allows you to switch maps in the matter of seconds. Whoever I come across with BM3 is always in my rear view and they think I run custom tunes. MHD> BM3 any day of the week.

[slaughter.mode]

Originally Posted by RElias21

This is interesting.

With respect to the OTS Stg. 2 setup, it sounds to me like you are saying that MHD stage 2 runs a few psi higher than BM3 stage 2?

Also, with respect to E85, did you ever compare it to the BM3 E85 maps? Otherwise, are you comparing apples to apples?

Lastly, for current BM3 owners, would you recommend MHD OR custom tuning via BM3?

Thanks.

Yes in respect to OTS Stage 2 apples to apples, MHD is running a good 4PSI higher from my logging over the last day.

I never tried a BM3 E85 map because I didn't want to pay for it. At that point I'd have paid a tuner, which I was planning to, until I found this MHD flex fuel option.

Can't really compare a OTS tune (BM3 or MHD) vs. a custom tune. Custom tuning with a reputable tuner is always the way to go for the best / safest improvements but if you're ever going down the Flex Fuel route and you want to keep it simple and as DIY as possible, MHD + their Ethanol CAN PnP solution is going to be the clear choice.

[chewbakam4]

Believe me if you added 4-6psi on top of any OTS map for 91 octane you’re kicking the shit out of your motor. 91 can’t take 26-28psi especially on an OTS map that’s meant to work on POS Arizona or Cali 91 octane, period. But whatever makes you happy or rocks your boat dude. If that works for you and doesn’t knock the just flash a Stage 2H OTS map and its like 24-25psi instead of 20psi

[slaughter.mode]

Originally Posted by chewbakam4

Believe me if you added 4-6psi on top of any OTS map for 91 octane you’re kicking the shit out of your motor. 91 can’t take 26-28psi especially on an OTS map that’s meant to work on POS Arizona or Cali 91 octane, period. But whatever makes you happy or rocks your boat dude. If that works for you and doesn’t knock the just flash a Stage 2H OTS map and its like 24-25psi instead of 20psi

Well, this is E30 so I think it's just fine for a OTS map. I'm getting 25.5 (maximum) PSI.

[hellokitty]

Originally Posted by the_ghost

Well, this is E30 so I think it's just fine for a OTS map. I'm getting 25.5 (maximum) PSI.

Seems quite high on just E30… I'm on a Cary Jordan full E85 flex fuel tune and he only pushes 24 psi peak. Max effort tuning on stock turbos is 26 psi.

[slaughter.mode]

Originally Posted by hellokitty

Seems quite high on just E30… I'm on a Cary Jordan full E85 flex fuel tune and he only pushes 24 psi peak. Max effort tuning on stock turbos is 26 psi.

Well this is what I'm reading in MHD---I would not be surprised if it's just not as accurate as my mechanical gauge. I had a boost metering blocked I removed because I'm making some adjustments. Possible error? I don't know.

To be fair, though, I don't have stock turbos.

[slaughter.mode]

I did some road testing on the Stage 2 E85 OTS map and it is impressively fast and smooth. Holy crap. It's giving me about 22-23PSI and it idles so smooth it feels like the car is off. This is great and even greater that it's free.

[Xer0449]

Originally Posted by hellokitty

Seems quite high on just E30… I'm on a Cary Jordan full E85 flex fuel tune and he only pushes 24 psi peak. Max effort tuning on stock turbos is 26 psi.

Assuming you're on the stock fuel system, that makes sense.

Anything beyond E50 on the stock fuel system needs boost to be scaled back to keep the pumps happy.

[slaughter.mode]

Update: I'm getting into the final revisions of my custom tune and with a rather modest 23PSI on E75 (ECA reading). Dyno today read 600whp (4 pulls). The difference between each pull was 1-5whp tops and I'm going to thank the Mishimoto charge cooler along with the CSF heat exchanger for that. Pretty awesome stuff. Had some un-registered mis firing in the upper RPM limit (ECA readings were clean) but we'll sort that out.

We have 5-8 PSI to go. I'll post the final dynos when we get there.

[Xer0449]

Originally Posted by nv_f82

Update: I'm getting into the final revisions of my custom tune and with a rather modest 23PSI on E75 (ECA reading). Dyno today read 600whp (4 pulls). The difference between each pull was 1-5whp tops and I'm going to thank the Mishimoto charge cooler along with the CSF heat exchanger for that. Pretty awesome stuff. Had some un-registered mis firing in the upper RPM limit (ECA readings were clean) but we'll sort that out.

We have 5-8 PSI to go. I'll post the final dynos when we get there.

Mind if I ask who's doing the tuning?

[Wanted_M]

Not sure if I missed it but who's tuning your M?

[Wanted_M]

HAHAHA, man look at the times for both our posts!! Can't believe we were thinking the same thing.

[slaughter.mode]

I haven't disclosed who is tuning, per their request. But not Cary Jordan if that's what the question is. LOL.

[Xer0449]

Originally Posted by nv_f82

I haven't disclosed who is tuning, per their request. But not Cary Jordan if that's what the question is. LOL.

LOL no, didn't think it was him. All good

[slaughter.mode]

Update 8/18/2021:

I decided to give my tuner a breather as we're running into some misfiring issues at the upper RPM range and give this MHD OTS Flex tune a try. I'm pretty damn impressed. The PSI is a bit on the low side 20-22PSI (I need to log it to validate for sure) but it is everything you'd expect from a mature OTS map. Idles smooth, starts smooth, and more than likely long term durable.

What's cool:
Their flex option works with multiple CAN ECA sensors, doesn't even have to be MHD's option from Bimecu. I can't stress how great this is for a OTS feature. Nobody else does this.

What's not so cool:
I do wish they allowed you to apply the Flex option to any of their OTS maps without having to use the multimap option but that's the way it's setup right now. So, since I care less about having multiple maps, I just placed the same map in all 4 slots.

Definitely read the manual but the way it works (if you want Flex) is you need to select 4 OTS maps for each 4 slots and not a single one of them can be a E-map (i.e. their S2 E85 map or the S2+ E30 map). Has to be normal fuel maps only. The Flex option then takes into account the levels of ethanol you have in your tank and modifies the fuel map you have accordingly based on Stage you selected, etc. It's quite robust.

[Wanted_M]

Is misfire plug gap related, coil or a bad injector? Any codes?
Sounds like MHD has the OTS full E maps sorted nicely for the masses.

[slaughter.mode]

Originally Posted by Wanted_M

Is misfire plug gap related, coil or a bad injector? Any codes?
Sounds like MHD has the OTS full E maps sorted nicely for the masses.

None of the above, it's custom tune related. I have no issues with OTS maps...they have been flawless.

[Levanime]

Levan from Bimmer ECU Solutions here,

If anyone has questions regarding our Kit, will be happy to answer questions

[slaughter.mode]

Originally Posted by Levanime

Levan from Bimmer ECU Solutions here,

If anyone has questions regarding our Kit, will be happy to answer questions

Thanks. So I think I've captured the issue with the MHD Can:

Kind of a boring video but my tank is full E85. After this erratic movement from the CAN sensor, it is now permanently stuck at 14% and I'm glad I'm on the OTS E85 S2 map or I'd be really having a rough time since flex tunes adjust and adapt based on this reading.

[Levanime]

The replacement module is already on the way that fixes the issue