N54 Stock DME Flex Fuel

[langsbr]

My understanding is that past E60, its just wasting fuel, and most full E85 setups are done for convenience of fill up, which shouldn't be a problem now with flex fuel. On stock turbos, you'll be limited to what, around 475ish WHP on full E85.

Without PI, I've seen some dynos of 600whp, most in the 550 range on hybrids - but they're usually using somewhere between E40 - E60.

My question regarding the flex fuel is - what's the ramification of running a higher E mix than what your max ethanol tune is?

 

[fmorelli]

Well but your last question comes back to my question colon have you seen anything written anywhere that says what the ethanol tune needs to be for Flexfuel?

Filippo

 

[LamboLover]

Implementing a somewhat similar setup for the later DMEs, I would say there is nothing in the implementation that forces you to do it any particular way. If you are only using a different mixture rarely, you could use known good or safe values for that and tune on your most frequently used fuel. If you are concerned about putting in too high an ethanol concentration and running out of fuel pump or risk of pre-ignition, you could reduce the boost as ethanol concentration goes too high. You can slice it how you/your tuner want to, and there will be many variants used I would think.

 

[langsbr]

you could reduce the boost as ethanol concentration goes too high. You can slice it how you/your tuner want to,

Is that a fact, or just assumption on how it works? For instance - can I say, run 25psi on E40, but if the mixture gets to >E70, dial it back to 22 psi so that I don't run out of fuel.

My initial understanding from the post a year ago was that it was Pump fuel / E fuel - interpolate "between" those with higher or lower timing, boost, and afr values. It's REALLY REALLY impressive if it can go the opposite direction when exceeding a certain metric as well.

 

[LamboLover]

This is an example of what I mean. I think Jake is doing it like this too - you can see in post #1.

 

[NoQuarter]

Is that a fact, or just assumption on how it works? For instance - can I say, run 25psi on E40, but if the mixture gets to >E70, dial it back to 22 psi so that I don't run out of fuel.

My initial understanding from the post a year ago was that it was Pump fuel / E fuel - interpolate "between" those with higher or lower timing, boost, and afr values. It's REALLY REALLY impressive if it can go the opposite direction when exceeding a certain metric as well.

Right. I dont think it is that at all. A simple Max/min tune and extrapolation between the two.

 

[LamboLover]

Well I copied his idea and that idea was to have different blending for fuel, ignition and load since that models the real life situations.

 

[NoQuarter]

That chart is saying call E62 the 100% point. If you put more than E62 in the tank is isn't going to do anything with that information.

 

[langsbr]

I thought it was saying use e62 as the highest load and reduce load above that.

 

[LamboLover]

It is just an example I quickly made for the thread.

blend = gasoline+(loadblend*(ethanol-gasoline))

Where "gasoline" is the lookup from the gasoline map, and "ethanol" is the lookup from the ethanol map.

You can think of the gasoline map as one extreme and ethanol the other. Then make the curves do what you want. Cook it how you like.

 

[LamboLover]

Your ignition curve may look like this: left hand side shows initial steep gains from knock suppression, right hand side avoids you crossing MBT because flame speed of ethanol is faster than gasoline.

 

[LamboLover]

Your fuel curve might look like this since its main role is to blend fuel correction and that is a linear relationship.

 

[matreyia]

I have no idea why people are discussing blends and ratios... MHD and Motiv kit are supposed to make this irrelevant. Otherwise there is no point in getting an automatic sensor and software solution to address variable ratios of fuel. Pop it in, install software and forget about mixing or flashing back and forth.

 

[langsbr]

Lambolover, are you developing this same thing for a different platform? I saw something about live running that I thought you had posted but it wasn't for N54 I didn't think.

Thanks for this info. This is the most technical stuff that's been released about this unless I've missed a different thread .

 

[LamboLover]

I have no idea why people are discussing blends and ratios... MHD and Motiv kit are supposed to make this irrelevant. Otherwise there is no point in getting an automatic sensor and software solution to address variable ratios of fuel. Pop it in, install software and forget about mixing or flashing back and forth.

It is a hugely configurable tuning system. You can if you wish leave the details to whatever OTS maps are coming for your spec, or your tuner. The material I posted above is about how it is tuned.

 

[LamboLover]

Lambolover, are you developing this same thing for a different platform? I saw something about live running that I thought you had posted but it wasn't for N54 I didn't think.

Thanks for this info. This is the most technical stuff that's been released about this unless I've missed a different thread .

I'm doing this for the slow ass N55 and slightly slower ass S55. There is a thread in the N55 section including a recent summary.

In some ways the N54 and S55 DMEs are very similar. In many other ways they are quite different. Jake's ideas are in the N55/S55 work, and some of my code is in the N54 work. We collaborate regularly.

 

[matreyia]

It is a hugely configurable tuning system. You can if you wish leave the details to whatever OTS maps are coming for your spec, or your tuner. The material I posted above is about how it is tuned.

thank god... I was getting cold feet thinking I'd have to mess with ratios and flashing over and over.

 

[fmorelli]

Bump.

 

[veer90]

Seriously guys what's the hold up...

 

[Terry@BMS]

Are the XDFs and stuff posted yet? Need to look in to this new integration to see if it makes sense to add a JB4 BEF option for it.