E85 Discussion - HPFP lubrication and Flow issues

[Fatguy729]

Whoa, so perhaps with e85 we could start using less idc... Maybe even lighten the tax on the fuel system for bt guys?

[Realgib3]

Originally Posted by Fatguy729 Whoa, so perhaps with e85 we could start using less idc... Maybe even lighten the tax on the fuel system for bt guys?

Yep. I posted earlier that running 13.5:1 netted me a 12-14% less idc whic gives a looooot more headroom

[Enki]

Max power rich:
1 gal E85 + 14 gal gas = E15, AFR = 12.34
2 gal E85 + 13 gal gas = E20, AFR = 12.29
3 gal E85 + 12 gal gas = E25, AFR = 12.24
4 gal E85 + 11 gal gas = E30, AFR = 12.19
5 gal E85 + 10 gal gas = E35, AFR = 12.13
6 gal E85 + 9 gal gas = E40, AFR = 12.08
7 gal E85 + 8 gal gas = E45, AFR = 12.03
8 gal E85 + 7 gal gas = E50, AFR = 11.98
9 gal E85 + 6 gal gas = E55, AFR = 11.92
10 gal E85 + 5 gal gas = E60, AFR = 11.87
11 gal E85 + 4 gal gas = E65, AFR = 11.82
12 gal E85 + 3 gal gas = E70, AFR = 11.77
13 gal E85 + 2 gal gas = E75, AFR = 11.71
14 gal E85 + 1 gal gas = E80, AFR = 11.66
15 gal E85 + 0 gal gas = E85, AFR = 11.61

[speedms6]

interesting stuff, i'd be interested in seeing the egt's before i do that though, can anyone help out with my post form before though? just to get off topic of correct afr's for a while, at least i know i'll just be running very rich, id rather feel safer doing that in the meanwhile, but how i go about the tuning, is this correct for now(disregarding what the best afr would be)?
so i read this whole damn thing over the past two days at work, and finished up this morning, my head hurts, but i think i have it grasped.

first, i have an ms6, so 16 gal gas tank, at some point this weekend i plan on adding 5 gal and filling the rest with 93.

my maf cal is good on 93 and if i get knock it will only be above 6200 i think its actually just noise, but with the e85 i will find out.

so, i should take a maf cal log, then adjust my CL for the new ltft's. there isnt really a reason to change anything above 100 g/s bc my cl/ol transition is like 1.2 or 1.25. so once above 100 g/s i think i am getting into OL. and no need for adjusting open loop bc the car takes the readings in lambda and the computer just gives a read out of the lambda in terms of the stoich scale for petrol. so if my WOT target afr meets my actual then all is good and i can start messing with boost a little(currently at 18.5 may try 20) and then from there mess with timing incrementally.

now, if i was to scale my whole maf cal, i would then also have to scale every table that had load on an axis. so say i multiply the whole maf cal by 1.15(not sure if that is correct dont feel like thinking about the math right now after reading 33 pages). Then in turn any table with load on the axis i would then multiply the whole table by 1.15, i assume not including ign timing, boost, but i would for the cl/ol transitions etc?

if this is all correct please let me know, and im not sure but i think i just summarized this thread."
"

[superskaterxes]

You only need to cal the cl part of your curve. The wot ol targets won't change but u will want to adjust them for max power.

Btw I'm pretty sure the above calcs are incorrect. What eq did u use to calculate these enki?

[Fatguy729]

Originally Posted by superskaterxes You only need to cal the cl part of your curve. The wot ol targets won't change but u will want to adjust them for max power. Btw I'm pretty sure the above calcs are incorrect

I was wondering, considering you mentioned 16 AFR earlier

[Enki]

I used the listed 11.6 for e85 as base for my calculations; if they are off, blame yourself superskaterxes

[superskaterxes]

I haven't figured out the correct eq yet to calc the afr based on different blends and that's why I diddent post it yet haha

[speedms6]

Originally Posted by superskaterxes You only need to cal the cl part of your curve. The wot ol targets won't change but u will want to adjust them for max power. Btw I'm pretty sure the above calcs are incorrect. What eq did u use to calculate these enki?

what about in terms of the load on the axis? if you scale you're maf, say 1.2 then when you're in actuality at 1.0 load you'll be reading 1.2 putting things into open loop sooner then they should? or should that not be a problem?

also the calcs dont make sense according to you're earlier post, but i dont tihnk the post makes sense

it says for e85 you divide by 1.5 to get you're true afr, you multiplied 10.7 x 1.5 to get 16, im skeptical of that.

do you think you might have to scale that 1.5 value as well for e30?

[superskaterxes]

Originally Posted by speedms6 what about in terms of the load on the axis? if you scale you're maf, say 1.2 then when you're in actuality at 1.0 load you'll be reading 1.2 putting things into open loop sooner then they should? or should that not be a problem? also the calcs dont make sense according to you're earlier post, but i dont tihnk the post makes sense it says for e85 you divide by 1.5 to get you're true afr, you multiplied 10.7 x 1.5 to get 16, im skeptical of that. do you think you might have to scale that 1.5 value as well for e30?

With cl load depending on how much e85 you run might not matter for every day part throttle driving. The transition point is def important so I would keep and eye on that.

You might be on to something with scaling that multiplier as well. Ill play with it in a little while

[rfinkle2]

I think it should be noted that many pumps in the US are pre-blended with up to 10% ethanol.

e.g. if running a 15 gallon tank, and you have 12 gallons of e10 (10%ethanol, 90 petrol), and 3 gallons of e-85 (85% ethanol and 15% petrol), you are effectively running a ~E25 blend.

EDIT: I see Enki's calculations above have already accounted for the additonal ethanol content.

Late to the party..

[phate]

You guys are making this more complicated than it really is.

[Refer to my "removing the voodoo" post a page or so back.]

[rfinkle2]

Originally Posted by phate You guys are making this more complicated than it really is. [Refer to my "removing the voodoo" post a page or so back.]

above referenced post here:

http://www.mazdaspeedforums.org/foru...ml#post1062438

[Bucker]

Originally Posted by Enki Max power rich: 1 gal E85 + 14 gal gas = E15, AFR = 12.34 2 gal E85 + 13 gal gas = E20, AFR = 12.29 3 gal E85 + 12 gal gas = E25, AFR = 12.24 4 gal E85 + 11 gal gas = E30, AFR = 12.19 5 gal E85 + 10 gal gas = E35, AFR = 12.13 6 gal E85 + 9 gal gas = E40, AFR = 12.08 7 gal E85 + 8 gal gas = E45, AFR = 12.03 8 gal E85 + 7 gal gas = E50, AFR = 11.98 9 gal E85 + 6 gal gas = E55, AFR = 11.92 10 gal E85 + 5 gal gas = E60, AFR = 11.87 11 gal E85 + 4 gal gas = E65, AFR = 11.82 12 gal E85 + 3 gal gas = E70, AFR = 11.77 13 gal E85 + 2 gal gas = E75, AFR = 11.71 14 gal E85 + 1 gal gas = E80, AFR = 11.66 15 gal E85 + 0 gal gas = E85, AFR = 11.61

Where is this from? What engine? What research?

Remember, "AFR" that we quote on this car for e85 is skewed. A LOGGED 14.7 on 100% E85 is an ACTUAL ~9.7.

[Enki]

Originally Posted by phate You guys are making this more complicated than it really is. (Refer to my "removing the voodoo" post a page or so back.)

At this point, we are trying to figure out the ideal AFR for the blended ratios. I've come pretty close with some basic math, but it still doesn't add up perfectly (the difference leaves you .25 AFR or so off what it should be at specific known value).

I already have the lambda scale figured out for any blend version you could possibly run, but figuring out where peak power (rich or lean) comes on at is a bit tricky. For example:

The max power (lean) for e85 is actually less on the lambda scale than either pure gas or pure eth, whereas the max power (rich) for e85 is nearly identical to pure eth, but VERY far away from gas.

Originally Posted by Bucker Where is this from? What engine? What research? Remember, "AFR" that we quote on this car for e85 is skewed. A LOGGED 14.7 on 100% E85 is an ACTUAL ~9.7.

This is using superskaterxes' base table (with 11.6 listed in the last row as the starting point) and everything is converted to lambda and back. It's a ratio based off of what skater already had in the table, basically; he said he needed to "finish" it so I assumed (incorrectly) that the value he had listed was accurate and went from there.

[phate]

nm

[Dano]

the multiplier is 1.47 to 1.50 so that variable needs to be considered, right?

From Supers post

If you must use an O2 sensor that only reports gasoline AFR information simply divide the numbers it reports by 1.47 - 1.50.

[Ziggo]

Here is the cheat sheet. All this mess about a reported 16afr being correct is way off base.




Zigatapatalka

[Bucker]

LAMBDA.

I just use the scaled MAF information... ~12 - 12.5 (gas AFR gauge) should be a great safety/power balance on most e85/93 blends. I like .86L which is a little leaner than those numbers.

Originally Posted by Ziggo Here is the cheat sheet. All this mess about a reported 16afr being correct is way off base. Zigatapatalka

Woah, what is that from? I like it!

[Dano]

Originally Posted by Ziggo Here is the cheat sheet. All this mess about a reported 16afr being correct is way off base. Zigatapatalka

could you make that just a lil smaller so I have more trouble reading it.

better yet post up the xls

[phate]

Originally Posted by Dano the multiplier is 1.47 to 1.50 so that variable needs to be considered, right? From Supers post If you must use an O2 sensor that only reports gasoline AFR information simply divide the numbers it reports by 1.47 - 1.50.

I hope you aren't serious.

This thread has turned to shit all because of that number, lol.

[superskaterxes]

fml i retract my previous statement haha

[Ziggo]

Originally Posted by Dano could you make that just a lil smaller so I have more trouble reading it. better yet post up the xls

If you would take those sunglasses off it would be fine!

I didn't save the xls, but can generate another later this evening if interested, it isn't rocket science.


Zigatapatalka

[Dano]

Originally Posted by phate I hope you aren't serious. This thread has turned to shit all because of that number, lol.

hum....your thread but IIRC the max power AF has never been discussed and I think it is useful information to know what to target for the various blends


* goes to back of class*

[superskaterxes]

ziggo,

your sheet is only based on a 12 gallon tank btw. i need to do some further reading before i respond back to this thread haha


from everything i have read, MBT of E85 isent that far off from pump gas and that the target AFR is really where u pick up some power.

[Enki]

Originally Posted by phate I hope you aren't serious. This thread has turned to shit all because of that number, lol.

Precisely why I was trying to scale based on lambda. Sorry if I shit on your thread unintentionally; just trying to figure out maths.

[Enki]

Wow, so my numbers above were almost dead on.

Edit: Well, not quite. Didn't scale well.

[phate]

Originally Posted by Dano hum....your thread but IIRC the max power AF has never been discussed and I think it is useful information to know what to target for the various blends * goes to back of class*

LOL, I wiped out my angry post, above, which explained some of this.

Anyway, I tested AFR on the dyno. This wasn't an all inclusive, end all be all set of sweeps, but I tested enough to know it wasn't worth my time or money to test it any more.

My findings are on page 20 with my other dyno results. The AFR change netted me nothing.

Some of you may remember, I got all over Dustin for this same reason, saying you couldn't possibly change AFR without changing power and timing and blah blah blah. My dyno time confirmed what he said, and made me a believer of using whatever AFR keeps your car from knocking and whatever doesn't scorch valves.


I think one important thing we all forget sometimes is that with direct injection, some of the old "rules" don't apply to us.

[Ziggo]

Originally Posted by superskaterxes ziggo, your sheet is only based on a 12 gallon tank btw. i need to do some further reading before i respond back to this thread haha from everything i have read, MBT of E85 isent that far off from pump gas and that the target AFR is really where u pick up some power.

I chose 12 gal because that's how much I typically fill up with. You want to run your tank pretty dry and mix to ratio, not just top off with gas if you want an accurate ratio.

Look at the PDF I sent you. MBT in terms of crank angle @ peak cylinder pressure is the same no matter the fuel. What changes is the burn rate of the fuel. If somehow you were able to reach MBT on race fuel, you would have to add extra timing if you switched to E85 to achieve the same results because it burns slower and thus requires more advance to generate peak cylinder pressure at the same crank angle.


Zigatapatalka

[rfinkle2]

[Enki]

So then commanding 11.5 AFR and hitting just over 12:1 with an e blend (no maf cal) shouldn't hurt power any.

[Realgib3]

Originally Posted by Ziggo Here is the cheat sheet. All this mess about a reported 16afr being correct is way off base. Zigatapatalka

Great sheet but I believe its still off since the whole thing based on e10 being 10% e85 when it should be 10% ethanol itself

[phate]

Let me summarize what my earlier post was trying to convey:

With e85 mix, YOU CANNOT PROVE THE AFR YOU ARE RUNNING AT AND IT DOESN'T MATTER. What matters is LAMBDA. If you understand this and can get over reported afr being inequal to actual afr, you are golden.

Lambda is always correct. You can calculate lambda from the reported AFR since 1.0 lambda DOES equal 14.68 in our ECU's terms.

[Ziggo]

Originally Posted by Realgib3 Great sheet but I believe its still off since the whole thing based on e10 being 10% e85 when it should be 10% ethanol itself

Yeah that's just a labeling issue I should have labeled it %Ethanol. Actually meant to hide that row.


If you are targeting 11.5 and getting 12.0 your MAFCAL is off by ~4% The 11.5 and 12.0 are just representations of lambda incorrectly assuming you are using pump gasoline. What you are actually doing is targeting .782 lambda and getting .816 it's not really a problem if .816 is within the max power range of your blend.

Like phate said, lambda is always right it's the interpretation into AFR that screws things up and gets people confused when using anything other than pump.


Zigatapatalka

[Bucker]

Just so anyone who is lost right now know, lambda is logged/stoich.

Stoich for gas is 14.68, so 1L = 14.68AFR on gas.

Stoich on e85 is ~ 9.7, so 1L = 9.7 on e85

L is constant, so regardless of the mix, the L number will represent your "actual" AFR.

[jonlax]

I went threw as much as possible and didn't see what i am going to share.

GM has been using direct injection and E-85 for awhile now. I worked on them for a good while also and noitced they have little problems when running E-85 straight (GM says not to mix Gas and E-85 because of some reason with pump failures) They don't really do anything special to the metal other than some coating....Feels like a coating of plastic.

So what i am getting at is having our factory or upgraded pumps coating in this (what ever it is). So now i continue to search. Bosch makes a reman unit for the eco-tec but does not list what they use to coat the internals. Anyway i will shoot back in a week or so after my parts guy gets me more info on the pumps and after i look into it more for the coating.


Edit/Addition to above:
Seems they also use this coating on the diesel engine pumps which are also Bosch made. Hopefully i can dig up some info!

[Lex]

Heh - I love how complicated this got. Here's a quick chemical background - this can hopefully clear things up.

You have to remember that in a given mixture (E85, gas, etc) you have a fuel and an oxidizer (O2).

The gasoline molecule is C8H18. This means that in 1 molecule you have 8 carbon atoms and 18 hydrogen atoms.

This is mixed with air (oxygen) to create combustion: 2C8H18 + 25O2 ~> 16CO2 + 18H2O

The molar ratio of these two for there to be no excess reactants left over is 14.7 : 1. So you need 14.7 O2 moles for C8H18 moles so that all reactants are used up.

Ethanol has a chemical formula of C2H5OH.

Notice that it contains carbon and hydrogen just like gasoline does BUT it also contains oxygen.

The combustion reaction of ethanol is C2H5OH (l) + 3 O2 (g) → 2 CO2 (g) + 3 H2O (g)

Now what you should notice is that the products of this combustion are also CO2 and water. However, you need LESS oxygen to use up all the reagents because ethanol CONTAINS oxygen itself.

So therefore you only need 9.0 moles of oxygen for 1 mole of ethanol to have complete combustion.

In other words, the stoich ratio between air and gasoline fuel is 14.7:1. The stoich ratio between air and ethanol is 9.0:1. This means AFR is fuel specific.

Lambda as was stated above is not. Stoich for any fuel is 1.0 lambda by definition. Lambda = AFR / AFR stoich

The O2 sensor in the car measures residual oxygen for any fuel used. In other words, any wideband can give you lambda (for any fuel) because it just tells you how much O2 is still passing by it regardless of the fuel used.

The AFR you see as 14.7 is just computed from the calibration for gasoline engines.

So if your Dashhawk tells you 14.7, it is equivalent to lambda 1.0 of any fuel you use. However to achieve 14.7 using ethanol you will have to inject a lot more fuel for the same amount of air you are pulling in.

So the MAF curve is scaled up to account for the oxygen that is present in the ethanol fuel. Although that is a little bit cheating since the oxygen is coming from the fuel, not the intake air, it gets the job done.

E85 approved vehicles have an E85 sensor that simply switches the ECU logic when it detects E85 is used.

[Ziggo]

Zigatapatalka

[silvapain]

Originally Posted by Lex Heh - I love how complicated this got. Here's a quick chemical background - this can hopefully clear things up. You have to remember that in a given mixture (E85, gas, etc) you have a fuel and an oxidizer (O2). The gasoline molecule is C8H18. This means that in 1 molecule you have 8 carbon atoms and 18 hydrogen atoms. This is mixed with air (oxygen) to create combustion: 2C8H18 + 25O2 ~> 16CO2 + 18H2O The molar ratio of these two for there to be no excess reactants left over is 14.7 : 1. So you need 14.7 O2 moles for C8H18 moles so that all reactants are used up. Ethanol has a chemical formula of C2H5OH. Notice that it contains carbon and hydrogen just like gasoline does BUT it also contains oxygen. The combustion reaction of ethanol is C2H5OH (l) + 3 O2 (g) → 2 CO2 (g) + 3 H2O (g) Now what you should notice is that the products of this combustion are also CO2 and water. However, you need LESS oxygen to use up all the reagents because ethanol CONTAINS oxygen itself. So therefore you only need 9.0 moles of oxygen for 1 mole of ethanol to have complete combustion. In other words, the stoich ratio between air and gasoline fuel is 14.7:1. The stoich ratio between air and ethanol is 9.0:1. This means AFR is fuel specific. Lambda as was stated above is not. Stoich for any fuel is 1.0 lambda by definition. Lambda = AFR / AFR stoich The O2 sensor in the car measures residual oxygen for any fuel used. In other words, any wideband can give you lambda (for any fuel) because it just tells you how much O2 is still passing by it regardless of the fuel used. The AFR you see as 14.7 is just computed from the calibration for gasoline engines. So if your Dashhawk tells you 14.7, it is equivalent to lambda 1.0 of any fuel you use. However to achieve 14.7 using ethanol you will have to inject a lot more fuel for the same amount of air you are pulling in. So the MAF curve is scaled up to account for the oxygen that is present in the ethanol fuel. Although that is a little bit cheating since the oxygen is coming from the fuel, not the intake air, it gets the job done. E85 approved vehicles have an E85 sensor that simply switches the ECU logic when it detects E85 is used.

All correct, except gasoline isn't just C8H18 (Octane). It also contains a great deal of Heptane (C7H16). Just a very, very minor correction.


Tapadatass

[Lex]

Originally Posted by silvapain All correct, except gasoline isn't just C8H18 (Octane). It also contains a great deal of Heptane (C7H16). Just a very, very minor correction. Tapadatass

Thanks Daniel. There are more details to this but I wanted to keep it relatively simple. We haven't even touched on reaction times and the fact that oxygen is in liquid form in ethanol blends