E85 and FAST

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
The following is from FAST's help line. While it concerns METHANOL only (not E85), it does indicate the challenges we will encounter tuning our cars to run any fuel other than gasoline!

(Frequently Asked Questions)

"CAN I RUN METHANOL WITH THIS SYSTEM?

- Yes you can. Methanol generally requires a little bit more than twice the volume of fuel over gasoline at full engine load, so you will need much larger injectors to provide an adequate supply of fuel. DO NOT use any fuel system lubricants or fragrance additives in your fuel when running an EFI-equipped vehicle with methanol. Use of these additives will likely result in clogged or damaged injectors.

-A decent way to approximate injector flow requirements for a methanol-burning engine is to simply divide flywheel horsepower by the number of cylinders:

Flywheel HP/# of Cylinders = Injector Flow Rate (lb/hr)

As an example, if you make 800 horsepower with your 8-cylinder engine, you will need a set of 100 lb/hr injectors to provide enough fuel for this engine.

-If you are using methanol on a vehicle being tuned in speed/density mode, you should change the "Injector Flow Rate" setting in the "Fuel Calculation Parameters" section to half of the actual fuel (injector) flow rate. This will cause the ECU to calculate twice the injector pulsewidth it normally would, thereby doubling the volume of fuel to the engine. So, if you were using the set of 100 lb/hr injectors described above, you should enter 50 lb/hr as the injector flow rate. If you are monitoring fuel consumption in lb/hr from C-ComWP, the number shown will be half of what is actually being used by the engine.

If you are tuning in Alpha-N mode, the above information does not apply. You should enter your actual injector flow rate in this case.

- The oxygen sensor will display air/fuel ratios when burning methanol. However, they will be displayed as conventional gasoline air/fuel ratios. This means that the ratio displayed is slightly more than twice as high as the actual ratio; in other words, a displayed air/fuel ratio of 12:1 is, in reality, about 6:1. Also, Lambda values are commonly used when tuning methanol-burning engines. There is a dashboard sensor called "Lambda" in C-ComWP that you can monitor if you are familiar with this measurement standard. Lambda measurements do not vary from one type of fuel to the next."



So, hopefully FAST will update this message for E85. This should be "food-for thought" for ALL OF US contemplating a change to E85!

I will try to modify the above to work for our 6 cylinder engines and post it so everyone can ponder (and correct) it.

Conrad
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
I didn't mean to "thumbs down" FAST for including the FAQ on ethanol only. I suspect that when it was done, that E85 was but a gleam in a chemist's eye. Quite to the contrary, I'm thrilled that they did so. It started me thinking about all this. I am merely suggesting that it would be GREAT if they did the same thing for the up-and-coming new fuel, E85. Seems to me that E85 could be a great business opportunity for FAST!

I see that you are a FAST dealer. I'm glad you stepped forward to lend your expertise. While it may be perfectly obvious to you how this needs to be done, there are many that are confused. Most of us would rather start with a GCT file that is "in the ballpark" for E85 and not risk a catastrophic engine failure due to a "too lean" situation. Perhaps you could re-write the ethanol section for E85 and post it here for all to read and learn. A little guidance on the modifications needed to the .GCT file would also be helpful what with the different timing, air-to-fuel requirements, and cold start challenges.

Can you help us?

Conrad
 

Blazer406

Mechanical Engineer
May 2, 2002
4,801
28
48
47
Terry, MS
www.beabulldog.com
I know I don't really have a dog in this fight.... but it should be fairly easy to do a little math with E85 and come up with a starter GCT file.... and start at real low boost.... with 02 correction limits +/- 25% ...... and get something that will work w/o risk of catastrophic (sp?) engine failure.

Small steps... grasshopper.... that is the key....IMHO

I'm sure however.... it will definately take some fiddling with to get the starting good at different temps.... and other drivability type issues....
 

Kevin87TurboT

How many can I own??
Jul 29, 2005
339
7
18
47
Ripley, MS
www.geocities.com
The latest XFI does have multiple fuel modes. You may not have the latest software version. Download version 1.34 and you'll also get the latest manual. It requires a fuel energy constant to be entered for your specific fuel. It's very straightforward. It also has the part that you quoted at the end of the new manual.

Here's the new portion of the manual.

Fuel Energy Constant

This parameter is a constant that defines the energy properties of a given fuel as the difference between it and gasoline (see table below). This strategy allows us a comprehensive range of fuel types and mixtures. The XFI ECU will compensate the fuel delivery based upon this parameter. While using the Lambda display mode will be more uniform in the display of the air/fuel ratio with different fuels, C-ComXFI will otherwise display all air/fuel ratios adjusted to the Fuel Energy Constant. Please note that the injector flow rate is still entered as lb/hr but as normally rated with gasoline.
Fuel Energy Constants (FEC) for Common Fuels
Fuel Type FEC Stoichiometric A/F
Compressed Natural Gas (CNG) 1.17 17.2:1
Liquid Propane (LP) 1.07 15.7:1
Gasoline 1.00 14.7:1
Methyl Tertiary Butyl Ether (MTBE) .796 11.7:1
85% Ethanol/Gasoline Mix (E85) .680 10.0:1
Ethanol (ETOH) .612 9.0:1
Methanol (MEOH) .439 6.45:1
 

TurboTR

sprayhead
May 25, 2001
1,167
1
36
57
Austin, TX
www.amd.com
I'll see if I can try this when I get the S2 mill back into the T. It already has 160 lb inj in it. I have a 1st gen FAST on it. Personally I wouldn't push my own car much past ~ the low 11's power level with E85 (it may very well handle more power with no problem, but OTOH S2 mills are increasingly rare and expensive...), but will try to tackle a couple of tanks of this and report what I find.

TurboTR
 

Alky V6

Let's go racing, boyz!
Jul 29, 2001
12,802
83
48
Santee, CA
www.drwtransmission.com
The latest XFI does have multiple fuel modes. You may not have the latest software version. Download version 1.34 and you'll also get the latest manual. It requires a fuel energy constant to be entered for your specific fuel. It's very straightforward. It also has the part that you quoted at the end of the new manual.

Here's the new portion of the manual.

Fuel Energy Constant

This parameter is a constant that defines the energy properties of a given fuel as the difference between it and gasoline (see table below). This strategy allows us a comprehensive range of fuel types and mixtures. The XFI ECU will compensate the fuel delivery based upon this parameter. While using the Lambda display mode will be more uniform in the display of the air/fuel ratio with different fuels, C-ComXFI will otherwise display all air/fuel ratios adjusted to the Fuel Energy Constant. Please note that the injector flow rate is still entered as lb/hr but as normally rated with gasoline.
Fuel Energy Constants (FEC) for Common Fuels
Fuel Type FEC Stoichiometric A/F
Compressed Natural Gas (CNG) 1.17 17.2:1
Liquid Propane (LP) 1.07 15.7:1
Gasoline 1.00 14.7:1
Methyl Tertiary Butyl Ether (MTBE) .796 11.7:1
85% Ethanol/Gasoline Mix (E85) .680 10.0:1
Ethanol (ETOH) .612 9.0:1
Methanol (MEOH) .439 6.45:1
Your fuel energies are a little misleading for anyone that is studying the values contemplating using the different fuels. You should post fuel energies at stoich mixtures to get a truer comparison of the different fuels as used in a combustion engine.

The flow rate of an injector will change a little with the difference in specific gravity of the fuel you choose to use.

Any aftermarket ECU will allow you to use different fuels. If you can do the math to translate O2 sensor gasoline a/f numbers to lambda and then to alcohol a/f numbers, you're in there. You just need to know what numbers to target for the different fuels. Simple stuff.

E85 a/f ratio will not be as bad as methanol. I would still run a minimum of one 160 lb/hr injector per runner. That will allow reasonable pulse width values @ WOT. Especially at 800 to 900 HP.
The cold start will be much better because of the gasoline mixed into it. In very cold weather, I'm not so sure.
Make sure your fuel system components will handle E85. Ethanol is still an alcohol.
Remove the thimble filter from the injector. Install inline filters close to the injector rails.
You CAN run top lubes with electronic injectors. And, I highly recommend you do so. At least, with methanol. I've been doing it for 6 years now. Maybe some top lubes will plug injectors. I haven't come across one yet.

What I want to hear about is someone throwing a little nitro percentage into their methanol motor. Lets pick this up.

Turbocharged 5% nitro mix with methanol and nitrous assist. What do you guys think? Big bang theory?
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
TurboTR,
Looking at my original post and your reply, I now see the "thumbs down" sign in the title. I completely missed your point! Sorry. I don't have a clue as to how that got there. I know that I didn't do it (at least not on purpose)! Guess I need to be more careful when typing a message. Wow!
Conrad
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
Donnie,
Thanks for the "fuel for thought" on the energy values. I'm going to have to think about that some. As far as the nitro additions, why don't you do it first and let us know how it goes. It DOES sound like the "Big BANG" theory. We can always depend on you to jazz things up!
Conrad
 

SS/GNX

Formerly NothinYet
Feb 13, 2007
762
0
16
burbs of Chicago, IL
I guess I just dont know why ANY of you guys want to run E-85...

I just dont get it?

For what purpose? What do you beleive you are gaining by running it?

I guess if you are doing it stricly to save on CO emmissions and help the environment, it makes sense...

Otherwise... I need someone to explain their reasoning...
 

HighPSI

Moderator
Staff member
May 24, 2001
5,384
312
83
Melbourne, FL
HartlinePerformance.com
Keep in mind. With an XFI, you can also buy the GM Fuel Sensor and have the XFI correct to whatever mixture of E85 and pump gas you have. This way you won't need to drain the tank each time. This is similar to the way the OEM are doing it.
 

jwillettgn

Member
Feb 8, 2006
499
0
16
63
China Grove, NC
Conrad,

Zack's friend Alvin @ PCM's for less has been playing with a Mustang with a fast system and running E-85. They have made 600RWH to date and the car is driven all the time. Next time I am at their shop I will check it out better. Alvin's shop is next the the Mooresville dragstrip, we are trying to set up a Buick Dyno day and track rental. Zack was wanting to run straight Methanol in the GN but can't with our fuel system at this time. Those new 120 lb./hr. injectors look to the the ticket for E-85.

Cal, it was good to see you again this weekend.

Jim
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
E85 brings two things to the table.

First of all, the octane rating is 105. Not too shabby!

Second, you may be familiar with alcohol injection and the cooling effect that the vaporization of alcohol has on the inlet air temperature (cools it). Well, here we are doing the same thing only much more of it in that we are running 85% ethanol along with 15% gasoline. You essentially have a chemical intercooler.

If you are running a stock (or near stock) motor and don't want to step it up a bit, then stick with 91 or 93 octane gasoline. If too much is never enough, then take a look at E85. It isn't nearly as corrosive as methanol but does attract water.

Does that answer your question?

Conrad


ps....As a mechical engineer, I think that there is a third less obvious advantage to E85. With a stand-alone alcohol injection system, you are depending on another mechanical device (alcohol pump) to operate properly (in addition to your fuel pump) to help your engine survive the boost that you have dialed in. If the alcohol injection pump fails under boost and you don't catch it, you may have a Big problem. With E85 in the tank, there is no auxilliary pump and if the fuel pump doesn't work properly, hopefully you will know it well before you get the engine under boost. i.e. the fewer mechanical devices the better.

I certainly think there is a place for both systems. Changing over to E85 may well be a big and expensive deal and I'm sure that everyone is not going to want to go to the trouble and expense to run E85. And then there is the limited availability of E85 problem at this time.
 

SS/GNX

Formerly NothinYet
Feb 13, 2007
762
0
16
burbs of Chicago, IL
Yes, thank you... i appreciate the run down.

All I kept ever hearing about it is how you need a huge fuel pump, lines, giant injectors... bla bla bla... sounded like it would cost more money than its worth...

But if used instead of an alky kit, I understand now...
 

Alky V6

Let's go racing, boyz!
Jul 29, 2001
12,802
83
48
Santee, CA
www.drwtransmission.com
Donnie,
Thanks for the "fuel for thought" on the energy values. I'm going to have to think about that some. As far as the nitro additions, why don't you do it first and let us know how it goes. It DOES sound like the "Big BANG" theory. We can always depend on you to jazz things up!
Conrad
Actually, the plan is to splash a little in after I'm satisfied with the tuneup. The CR of this engine is perfect for a small percentage. I'll post the results. Good luck with the E85. It's nice to see some experimenting.
 

Steve

Well-Known Member
Jun 1, 2001
1,198
72
48
118
Springfield, Missouri
Visit site
I guess I just dont know why ANY of you guys want to run E-85...

I just dont get it?

For what purpose? What do you beleive you are gaining by running it?

I guess if you are doing it stricly to save on CO emmissions and help the environment, it makes sense...

Otherwise... I need someone to explain their reasoning...
Check out the results from the Dynomax Dyno Challenge that they had at various national events and the finals at SEMA. There were cars making 1200 rwhp on E85! All of the big hitters from the challenge were running E85.
 

Hot Air

E85 and S.E./Carolinas Moderator
Staff member
Nov 11, 2002
3,072
28
48
Durham, North Carolina
For those of you that don't know DonWP (Donnie Wang), he is an extreme innovator on Buick V6 turbocharged engines. He doesn't just "think outside the box", he "lives outside the box"! Donnie is a DEEP thinker that accepts nothing at face value. For him to tell us he is going to add a 'splash' of nitro translates into WAY more than a splash. When I think of Donnie, I thank of the innovator Don Gartlis (the Top Fuel guy from years ago) who was always years ahead of his competition.
Conrad

ps...I have to admit, I never (and still don't) considered nitro for my Buick. Shoot, nitrous scares me!

pss...Donnie runs and owns a killer transmission shop!
 
Top Bottom