E85 Discussion - HPFP lubrication and Flow issues

[phate]

Originally Posted by 06Speed6 Arent the fueling tables in the ecu in lambda? In versatune all of the fueling tables are lambda so its easy to set the proper afr regardless of fuel type.

Yes, but that lambda is still based on the 14.68:1 gasoline scale.

@silvapain had it right.

You would actually need to scale lambda in order to run the proper lambda, LOL!

Originally Posted by silvapain Yes. The numbers in the ATR table are from COBB; the PCM deals in lambda like Phate said. That's what the WBO2 reads in. The issue is that the PCM uses petrol's stoich value to determine the amount of fuel to add. Fuel to add = AFR target (lambda) * MAF g/s * petrol stoich Until COBB reveals this value for us to edit, we have to compensate by skewing one of the other values. So far everyone has done it by skewing the MAF signal; I'm suggesting we try skewing the AFR target. Once COBB reveals the stoich constant, all we would have to do to switch to E85 would be to change one single value. Makes me wet just thinking about it. Tapadatass

There it is^^

[J-Liss]

O SNAPS DANNY BOY THE BEARD SPEAKS

[Ziggo]

Originally Posted by phate Yes, but that lambda is still based on the 14.68:1 gasoline scale. @silvapain had it right. You would actually need to scale lambda in order to run the proper lambda, LOL! There it is^^

Maybe I don't have my head on straight, but if you slewed lambda/AFR wouldn't your fuel trims be way off? IE, the car is going to try to eat your slew in closed loop? Or would you just spoof the lambda in open loop tables only? That makes for a tricky transition depending on how much E85 you are running, and you may throw CELs in closed loop.

Lambda = 1 is stoich for all fuels. The translation to AFR is based on gasoline and is done in ATR. What is probably in the ECU is a fuel constant relating that fills in the following simplified equation:

(Calc load*constant)/lambda target=pulsewidth

The current method to spoof the pulsewidth higher is to spoof the Calc load higher thru maf curves

Slewing the lambda target could work, given the problems I see above

Adjusting the constant would be the best solution

Maybe I just gotta get my head around this, but even with the load axis issues I think scaling the MAF is the better way to go till we can access the constant.

[phate]

Originally Posted by Ziggo Maybe I don't have my head on straight, but if you slewed lambda/AFR wouldn't your fuel trims be way off? IE, the car is going to try to eat your slew in closed loop? Or would you just spoof the lambda in open loop tables only? That makes for a tricky transition depending on how much E85 you are running, and you may throw CELs in closed loop. Lambda = 1 is stoich for all fuels. The translation to AFR is based on gasoline and is done in ATR. What is probably in the ECU is a fuel constant relating that fills in the following simplified equation: (Calc load*constant)/lambda target=pulsewidth The current method to spoof the pulsewidth higher is to spoof the Calc load higher thru maf curves Slewing the lambda target could work, given the problems I see above Adjusting the constant would be the best solution Maybe I just gotta get my head around this, but even with the load axis issues I think scaling the MAF is the better way to go till we can access the constant.

Hehe, isn't this fun. In atr and our ecu's fueling tables, lambda only means 14.68:1. 14.68 is the stoich constant found in the ECU, somewhere. Anyway, I'm going to drink some more beer.

The only place where lambda really means lambda is from the O2 sensor readings

[Realgib3]

Tried running 13.5-14:1 Targets today with only 1.8 gal of E... Stupid fucking fast, no kr and sent IDC's plummeting from 90+ to 75-77%... hmmm if this is really an option and doesn't cause egt issues, then I just found a lot more room for power

[Dano]

R u trying to blow #2. Lol

12-13 AF is optimal for petrol.


Tappin

[Realgib3]

Originally Posted by Dano R u trying to blow #2. Lol 12-13 AF is optimal for petrol. Tappin

Can't help but test new things lol.

I had talked to a cobalt guy running 14:1 on meth, making great power... so I figured I'd give it a try with just a little E... and I gotta tell ya, it looks kinda promising.

Taking this testing seriously though and watching everything very closely of course.

[Dano]

Lol

I can't keep up w the cross posting

GL w the testing for sure. Do you have EGT. If not get one ASAP.

Then go back to reg AF then compare. Right?


Tappin

[Realgib3]

Lol too many posts, too many threads! Have an egt...not in use but it will be put to use this weekend

[Dano]

you guys may already know this and I suppose it doesn't really matter due to the badassness of E85.

most people say the octane rating of E is between 105-107, and as high as 113 which is not really the case and its more like 94-96 apparently.

from Wiki

E85 - Wikipedia, the free encyclopedia

E85

There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests."

anyway just late night posting...

[hamptotl]

Ok I haven spent seriously all day reading this thread in its 33 page entirety. I am drooling on myself and twitching right now. I feel a little retarded but so much more well informed.

Phate I will forever know you now as ethzilla thats all there is to it.

You and everyone else with your tests and findings are absolutely amazing and I couldnt begin to thank you all enough for all of the win and genious in this thread.

I am currently in the process of tuning with Dustin and I am sprayng 100% meth out of a D07 nozzle and running a perfect 3/9 ratio every fill up. I still dont know if we have pushed this ratio to its limits but I am all about giving it a try.

It may have been done and I just forgot about it after thirty three pages but what the hell. Dustin well talk man and again Phate Driver 12pk bewsted and everyone else thank you so much for everything in this thread and all your contributions to my fueling joy.

[cld12pk2go]

Yeah, Phate the only way to really know when the switch occurs is by watching trims.

The other interesting thing about E85, is my gas stations apparently only refill their E85 tanks every few weeks instead of every few days like their gas tanks.

Obviously, this is due to much lower demand and thus turnover of the E85.

Here is the link again with the E85 mix class by month/state.

E85 Mustangs.com - Regional Fuel Chart by state

I should be expecting Class II now (min 74% ethanol).

[cld12pk2go]

Originally Posted by Dano you guys may already know this and I suppose it doesn't really matter due to the badassness of E85. most people say the octane rating of E is between 105-107, and as high as 113 which is not really the case and its more like 94-96 apparently. from Wiki E85 - Wikipedia, the free encyclopedia There is no requirement to post octane on an E85 dispenser. If a retailer chooses to post octane, they should be aware that the often cited 105 octane is incorrect. This number was derived by using ethanol’s blending octane value in gasoline. This is not the proper way to calculate the octane of E85. Ethanol’s true octane value should be used to calculate E85’s octane value. This results in an octane range of 94-96 (R+M)/2. These calculations have been confirmed by actual-octane engine tests." anyway just late night posting...

The octane numbers are obviously bogus for E85, but due to the epic cylinder cooling related to the 3x latent heat of vaporization difference it acts like ~116 octane race fuel with respect to detonation avoidance, which is what the octane number is supposed to be telling us anyways.

[Dano]

Originally Posted by Dano you guys may already know this and I suppose it doesn't really matter due to the badassness of E85.

Originally Posted by cld12pk2go The octane numbers are obviously bogus for E85, but due to the epic cylinder cooling related to the 3x latent heat of vaporization difference it acts like ~116 octane race fuel with respect to detonation avoidance, which is what the octane number is supposed to be telling us anyways.

so what you are really saying is that the 105, 107, 116 is the badassness rating of E85 not the octane rating....thanks for confirming what i said

[BigjohnB20]

Thats badassness on the (R+M)/2 scale right?

[Dano]

LOL heres the different methods

105,107,116 (badassness) method

94-96 (R+M)/2) method

but again as I said it doesn't really matter what the octane "number" is because the real world advantages far outreach what the number would indicate its deto resistance is.

I only brought it up b/c i was having an argument with a buddy of mine who kept saying the official rating was like 107...then I googled it and found what wiki stated.

now back to the fun.

[Realgib3]

Originally Posted by BigjohnB20 Thats badassness on the (R+M)/2 scale right?

No badassness is a scale of it's own and E is at the top fo shooo

[Dano]

BTW....I disabled my WMI and can now get KR on a 3/9 gallon mix with the below timing from 2.5K

1.00	2.00	6.50	9.00	10.50	11.50	13.50	15.00	17.00	18.00

Knock is in the 1.0 to 2.0 range randomly around 5-5.5k...with meth it isn't present so I'll continue to run the timing curve.

[Ziggo]

Thanks for the data point sans meth. Any chance I can see the rest if that log? I am interested in your BAT results without meth.


Zigatapatalka

[silvapain]

Originally Posted by Dano BTW....I disabled my WMI and can now get KR on a 3/9 gallon mix with the below timing from 2.5K 1.00 2.00 6.50 9.00 10.50 11.50 13.50 15.00 17.00 18.00 Knock is in the 1.0 to 2.0 range randomly around 5-5.5k...with meth it isn't present so I'll continue to run the timing curve.

Offtopic: do I see you increasing VVT at high RPMs? Do you have any empirical evidence of power gains from this?


Tapadatass

[Dano]

Originally Posted by Ziggo Thanks for the data point sans meth. Any chance I can see the rest if that log? I am interested in your BAT results without meth. Zigatapatalka

sure thing homie....These logs were taken while I was working on my boost and AF so you'll see my highlighted portions which indicate the issues I am addressing.

anyway 2 logs attached but I was "quick logging" close to home so I wasn't reving all the way out.

[Dano]

Originally Posted by silvapain Offtopic: do I see you increasing VVT at high RPMs? Do you have any empirical evidence of power gains from this? Tapadatass

hahah no I am not...you are seeing the VVT actuator acting up I guess....if you are referring to those .62 numbers??

my VVT goes to 0 @ 5K but I do run 35 up to 2500 and am going to move that to 3K one of these days. I seem to never be able to finish anything LOL

once I get my E85 tune cleaned up I'll go back to VVT testing. Really this time of year is not ideal for VVT experiments on the street as AMB temps change too much to quantify results.

[phate]

Originally Posted by hamptotl Ok I haven spent seriously all day reading this thread in its 33 page entirety. I am drooling on myself and twitching right now. I feel a little retarded but so much more well informed. Phate I will forever know you now as ethzilla thats all there is to it. You and everyone else with your tests and findings are absolutely amazing and I couldnt begin to thank you all enough for all of the win and genious in this thread. I am currently in the process of tuning with Dustin and I am sprayng 100% meth out of a D07 nozzle and running a perfect 3/9 ratio every fill up. I still dont know if we have pushed this ratio to its limits but I am all about giving it a try. It may have been done and I just forgot about it after thirty three pages but what the hell. Dustin well talk man and again Phate Driver 12pk bewsted and everyone else thank you so much for everything in this thread and all your contributions to my fueling joy.

You're my hero for reading this entire thread in a day

[GLORIFIEDBOZO]

Originally Posted by hamptotl Ok I haven spent seriously all day reading this thread in its 33 page entirety. I am drooling on myself and twitching right now. I feel a little retarded but so much more well informed. Phate I will forever know you now as ethzilla thats all there is to it. You and everyone else with your tests and findings are absolutely amazing and I couldnt begin to thank you all enough for all of the win and genious in this thread. I am currently in the process of tuning with Dustin and I am sprayng 100% meth out of a D07 nozzle and running a perfect 3/9 ratio every fill up. I still dont know if we have pushed this ratio to its limits but I am all about giving it a try. It may have been done and I just forgot about it after thirty three pages but what the hell. Dustin well talk man and again Phate Driver 12pk bewsted and everyone else thank you so much for everything in this thread and all your contributions to my fueling joy.

Originally Posted by phate You're my hero for reading this entire thread in a day

What phate said, I can't imagine the pain that comes with that, or the spare time you must have to do it.

[zenger]

No logs from the actual dyno, and my tuner still hasn't gotten back to me to get me a dyno sheet; but here is a short log from the track

and my tune

[zenger]

btw have no clue how to view that ptm file maybe one of you guru's can do something with it?

[Enki]

Should be raw text.

[Ziggo]

Originally Posted by Dano sure thing homie....These logs were taken while I was working on my boost and AF so you'll see my highlighted portions which indicate the issues I am addressing. anyway 2 logs attached but I was "quick logging" close to home so I wasn't reving all the way out.

Thanks, that pretty much confirmed my suspicions. Shopping for BPVs now....


Zigatapatalka

[BigjohnB20]

Maybe I am missing something from that log, but I see:

AFR @15:1 at 22+ psi (I know it is skewed for E, but looks weird still)
Accel pedal @ 99% but throttle position in the 4s?
Essentially 0 WGDC across the whole log even when pushing 23psi.

Edit: I meant from Zenger. Coupel peeps posted in between

[phate]

Originally Posted by BigjohnB20 Maybe I am missing something from that log, but I see: AFR @15:1 at 22+ psi (I know it is skewed for E, but looks weird still) Accel pedal @ 99% but throttle position in the 4s? Essentially 0 WGDC across the whole log even when pushing 23psi. Edit: I meant from Zenger. Coupel peeps posted in between

I had to open the log at work because of this. My guess (hope) is O2 sensor is not reading properly?? Anyway, I'm out the door, so I'll look at it when I'm home.

[J-Liss]

Originally Posted by phate I had to open the log at work because of this. My guess (hope) is O2 sensor is not reading properly?? Anyway, I'm out the door, so I'll look at it when I'm home.

thats exactly what i was thinking.

[hamptotl]

It wasn't too painful lol but holy shit it was an amazing read. I'm going to be calling Dustin tonight so I can talk meth with him and my tune. I am thinking dano has found the three gallon timing limits. We will def see for sure plus I am running meth also. We shall see for sure and again guys thanks a lot you have educated the he'll out of me through this thread

[Dano]

on a DO7 100% meth I saw absolutely no knock so take that for what its worth. on meth I could run more timing but no way to know if I am already at MBT so I am staying put.

I actually added 1* across the board and saw no gains in VD plots for what that's worth so I think I am good. Could be that more than 1* is necessary to plot the difference who knows...lol

car absolutely rips at ~70-80* temps. actually barked the tires shifting into 4th lastnight

note to self: re-enable FFS and test that...nooooooo wait dano...finish something first .....

[Hamilton69]

Someone should make cliffnotes and post in the start of the thread lol I read the first 10 pages and my head hurts! Thank you guys for what your doing!

[speedms6]

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.

[zenger]

Phate what think ? About my log is it fubar?

[Fatguy729]

Originally Posted by speedms6 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.

BUMP for input on this^^^^^.




Phate, I got my TP installed yesterday, loaded up OTS stage 2 tune... gonna get my MAF cal done tonight (for 93) and will be ready for EEEEEEEEEEEEEEEEEEEEEE!!!!!!!!!!!! expect pm soon, but I understand if you can't get to me immediately.







Quick question... The station by me that sells eth has 93 and 94 octane gas, 94 is 10 cents more than the 93. Would there be enough benefit from using the 94 to justify spending the extra $$ ?

[Dano]

no need for 94 octane if you will be mixing with E....hell Imma gonna try me some 91 after I get my tune finished.

[superskaterxes]

Originally Posted by Realgib3 Tried running 13.5-14:1 Targets today with only 1.8 gal of E... Stupid fucking fast, no kr and sent IDC's plummeting from 90+ to 75-77%... hmmm if this is really an option and doesn't cause egt issues, then I just found a lot more room for power

did anyone bother to read the sticky i put in this section on E85?

a link for your reference:

http://www.mazdaspeedforums.org/foru...uel-faq-92889/


we need to go back to the AFR topic because some people in this thread are way off and with all the new kids coming to town (me included) we dont want to lead anyone in the wrong direction.

lets get some data down first:

 
Fuel                      AFRst     FARst     Equivalence   Lambda 
----                      -----     -----       Ratio       ----- 
=======================--==================================== 

Gasoline   stoich          14.7    0.068       1           1 
Gasoline Max power rich    12.5    0.08        1.176       0.8503 
Gasoline Max power lean    13.23   0.0755      1.111       0.900 

=======================--==================================== 

E85 stoich                 9.765    0.10235    1          1 
E85 Max power rich         6.975    0.1434     1.40       0.7143 
E85 Max power lean         8.4687   0.118      1.153      0.8673

the best AFR to run for max power on gasoline is 12.5-13.2

the best AFR to run for max power on 100% E85 is 7-8.5


you guys need to remember that this is NOT ON THE SAME SCALE when it comes to our ECU. because our ECU is programmed to the 14.7 stoich AFR of gasoline, we need to adjust our WOT AFR's for max power on E85.

at the bottom of part 3 of the sticky is this:

will a wide band O2 sensor accurately read fuel air mixtures with E85 blends ? To get an accurate AFR reading you need to switch the meter to Lambda or equivalence ratio setting rather than AFR. Most O2 sensors assume you are running gasoline and will report a stoichiometric mixture as 14.7:1 which is the proper value for gasoline. E85 has a Stoichiometric mixture of between 9.7 - 10:1 and a max power mixture of about 6.98-8.5:1 or so, where with gasoline it is 12.5:1-to 13.1. If you must use an O2 sensor that only reports gasoline AFR information simply divide the numbers it reports by 1.47 - 1.50. On gasoline, my ECU is supposed to give a mixture of 11.5:1 and on 100% E85 the dyno's wide band reported an AFR of 11.6:1. That means that my true AFR on the E85 was about 7.8:1 which is right in the middle of max power mixtures for E85.

it basically says that in order to make MAX power on 100% E85, you need to be running an ~11.5 AFR on our ECU (since it was programmed for gasoline).

now most people here are not running 100% E85 so now you need to compensate. if you use the same equation above you can calculate what AFR you need to run on an E85 Blend. According to the attached fuel sheet in that sticky, E30 (close to what most people here are playing with) needs an AFR of 10.7 to make max power. but that AFR is relative to E85 and NOT gasoline.



here are some common gasoline to E85 mix ratio's and what target AFR in ATR you should be using for max power. (NOTE: all gas values assume 10% eth is added, AFR based on 7.75 AFR of E85 which is the mid-range for MAX power)

2 gal E85 + 13 gal gas = E20, AFR =
2 gal E85 + 13 gal gas = E20, AFR =
3 gal E85 + 12 gal gas = E25, AFR =
4 gal E85 + 11 gal gas = E30, AFR =
5 gal E85 + 10 gal gas = E35, AFR =
6 gal E85 + 9 gal gas = E40, AFR =
7 gal E85 + 8 gal gas = E45, AFR =
8 gal E85 + 7 gal gas = E50, AFR =
9 gal E85 + 6 gal gas = E55, AFR =
10 gal E85 + 5 gal gas = E60, AFR =
11 gal E85 + 4 gal gas = E65, AFR =
12 gal E85 + 3 gal gas = E70, AFR =
13 gal E85 + 2 gal gas = E75, AFR =
14 gal E85 + 1 gal gas = E80, AFR =
15 gal E85 + 0 gal gas = E85, AFR = 11.6

EDIT: I need to come back to the AFR calc as i cant finish it right now

Originally Posted by cld12pk2go The octane numbers are obviously bogus for E85, but due to the epic cylinder cooling related to the 3x latent heat of vaporization difference it acts like ~116 octane race fuel with respect to detonation avoidance, which is what the octane number is supposed to be telling us anyways.

pure ethanol has an octane rating of 113 (can be found on the attached sheet in the sticky). now as you add gasoline to that (which is ~93 octane) the total octane is of course going to go down. so the fact that you have heard anywhere from 94-107 octane for E85 is 100% true except those people failed to mention what blend they were using to reach that octane.

[Realgib3]

Originally Posted by superskaterxes did anyone bother to read the sticky i put in this section on E85? a link for your reference: http://www.mazdaspeedforums.org/foru...uel-faq-92889/ we need to go back to the AFR topic because some people in this thread are way off and with all the new kids coming to town (me included) we dont want to lead anyone in the wrong direction. lets get some data down first: Fuel AFRst FARst Equivalence Lambda ---- ----- ----- Ratio ----- =======================--==================================== Gasoline stoich 14.7 0.068 1 1 Gasoline Max power rich 12.5 0.08 1.176 0.8503 Gasoline Max power lean 13.23 0.0755 1.111 0.900 =======================--==================================== E85 stoich 9.765 0.10235 1 1 E85 Max power rich 6.975 0.1434 1.40 0.7143 E85 Max power lean 8.4687 0.118 1.153 0.8673 the best AFR to run for max power on gasoline is 12.5-13.2 the best AFR to run for max power on 100% E85 is 7-8.5 you guys need to remember that this is NOT ON THE SAME SCALE when it comes to our ECU. because our ECU is programmed to the 14.7 stoich AFR of gasoline, we need to adjust our WOT AFR's for max power on E85. at the bottom of part 3 of the sticky is this: it basically says that in order to make MAX power on 100% E85, you need to be running an ~11.5 AFR on our ECU (since it was programmed for gasoline). now most people here are not running 100% E85 so now you need to compensate. if you use the same equation above you can calculate what AFR you need to run on an E85 Blend. According to the attached fuel sheet in that sticky, E30 (close to what most people here are playing with) needs an AFR of 10.7 to make max power. but that AFR is relative to E85 and NOT gasoline. so the above equation for E30 would be 10.7 x 1.5 = 16 AFR on our ECU. this would prob explain why realgib feels this giant power increase because an AFR of 14 is ALOT closer to 16 then the previous ~12.5 he was prob running. This means that the LOWER the blend of E85 you use, the HIGHER your target WOT AFR needs to be in order to make max power. here are some common gasoline to E85 mix ratio's and what target AFR in ATR you should be using for max power. (NOTE: all gas values assume 10% eth is added, AFR based on 7.75 AFR of E85 which is the mid-range for MAX power) 2 gal E85 + 13 gal gas = E20, AFR = 2 gal E85 + 13 gal gas = E20, AFR = 3 gal E85 + 12 gal gas = E25, AFR = 4 gal E85 + 11 gal gas = E30, AFR = 5 gal E85 + 10 gal gas = E35, AFR = 6 gal E85 + 9 gal gas = E40, AFR = 7 gal E85 + 8 gal gas = E45, AFR = 8 gal E85 + 7 gal gas = E50, AFR = 9 gal E85 + 6 gal gas = E55, AFR = 10 gal E85 + 5 gal gas = E60, AFR = 11 gal E85 + 4 gal gas = E65, AFR = 12 gal E85 + 3 gal gas = E70, AFR = 13 gal E85 + 2 gal gas = E75, AFR = 14 gal E85 + 1 gal gas = E80, AFR = 15 gal E85 + 0 gal gas = E85, AFR = 11.6 EDIT: I need to come back to the AFR calc as i cant finish it right now pure ethanol has an octane rating of 113 (can be found on the attached sheet in the sticky). now as you add gasoline to that (which is ~93 octane) the total octane is of course going to go down. so the fact that you have heard anywhere from 94-107 octane for E85 is 100% true except those people failed to mention what blend they were using to reach that octane.

Is it wrong to say I love you?

Btw I went back to 12.3 targets today and lost a ton of power, mostly up top. Not sure if its from being richer or because of the higher idc,s though...