Racing with E85

Bullshark

Well-known member
Joined
Mar 23, 2008
Messages
710
Location
St. Charles, Missouri
One of the Sharks here in STL just set the NCCC drag record for B2 class using E85 (congrats larrywalk).
[ame="http://www.youtube.com/watch?v=PB--_-mM0bI"]http://www.youtube.com/watch?v=PB--_-mM0bI[/ame]
He tried to explain the technical aspects of the HP gain over a few beers last night but either his or my brain was already toast. :mobeer: It prompted me to do a little research on the topic and found this interesting site.

http://iqlearningsystems.com/ethanol/racers.html

Turns out this guy is also located here in St. Charles, so I might take the time to look him up. He kind of lost some creditability with me though when he sited carburation as having the benefit of more WOT HP. Something you guys already know my position on:crap: Ha Ha

I just purchased the new Holley Dominator EFI ECU and wire harness and want to look at different configurations.

Anyone here have experience with Ethanol (E85) setups for racing? I would be interested in your thoughts

Bullshark
 
Last edited:
I haven't used E85 pump gas, but I did use a "similar" 85% ethanol aviation gas (110 octane, IIRC) for several years in my '84. I had an EEPROM adapter in my ECM so I could swap cal chips depending on my fuel usage at the time. My '84 isn't intercooled, so I liked the charge cooling of the alcohol fuel, along with the additional octane to help preserve the pistons while I was dialing in the Spark and VE tables.
I only ran this fuel on track days, and then diluted it with straight gasoline after the event was over due to concerns about any fuel line/tank corrosion issues.
The exhaust smell was always amusing with that fuel.
 
thanks for the reply Mike, for a minute there I thought everyone thought I was still three sheets to the wind. :lol: What kind of hp increase do you think you realized?, Did you up the compression or run boost? Looking at this new Holley EFI system, It appears "relatively" easy to accommodate multiple setups.

Bullshark
 
thanks for the reply Mike, for a minute there I thought everyone thought I was still three sheets to the wind. :lol: What kind of hp increase do you think you realized?, Did you up the compression or run boost? Looking at this new Holley EFI system, It appears "relatively" easy to accommodate multiple setups.

Bullshark

I honestly can't quantify the hp increase with this fuel. I found a source (a small airport in the midwest) for that fuel part way into the calibration process. The engine is an 8:1 CR 355, and 93 octane was fine during the early stages of tuning. I just started running the engine a bit harder and at higher coolant temps as the process evolved. I frequently ran into significant detonation with 93 fuel, and the avgas allowed me to calibrate the spark curve at increasing boost and temperature levels.
I was able to get the system to work safely at 7 pounds of boost for the individual 20 minute tuning sessions at my favorite track, but I was getting increasingly uncomfortable running at higher boost levels due to the software and I/O limitations of the stock '84 ECM. The '84 has great throttle response, and pulls like a bigblock when under boost, but I'm working on wiring up a later model ECM to allow a bit better fuel and spark control under boost. As I mentioned, this is a non-intercooled application, so if I can eventually get reliable operation at 10# of boost I'll be happy.
Typically this type of fuel makes more horsepower. In my case it's just icing on the cake, as my main focus was the charge-cooling and higher octane qualities of this fuel.
 
As I mentioned, this is a non-intercooled application, so if I can eventually get reliable operation at 10# of boost I'll be happy.
Typically this type of fuel makes more horsepower. In my case it's just icing on the cake, as my main focus was the charge-cooling and higher octane qualities of this fuel.

Amen, that is why I am thinking about ethanol capability. That, and my friend's success at the track (Carbureted) started me thinking about configuring a new engine for my 69 BB Vette. It is old school 427 muscle with 12:1 compression, old Fireball Crane cam with lots of overlap, 4.ii rear, etc. Considering a new engine, I was wondering what might be the best approach leveraging the Holley EFI Dominator capabilities. Quick and easy configuration between fuels with boost control opens up a lot of performance capability it seems to me. Ethanol fuels for racing, pump gas for street? Basically, If I was to build a BB engine for the 69, what might it be? Is there enough potential gain in each direction to make something like this worth doing.
Just thinking out of the box a little here. BTW, is there some reason you are shying away from an intercooler? I'm not a Turbo expert. :confused2:
 
Bob, In my mind the dilema for a E85/Gasoline engine would be the fixed flow rate of the injectors. According to the chart below. It looks like you need to supply 150% more E85 than gasoline:

The energy of ethanol relative to gasoline
A. 76,000 = BTU of energy in a gallon of ethanol
B. 116,090 = BTU of energy in a gallon of gasoline
C. .655 = 2/3 = GGE of energy in a gallon of ethanol
D. 1.53 = Gallons of ethanol with the energy of 1 gallon of gasoline

Assuming that the WOT duty cycle of the injectors is 80% with E85, you would be running 53% WOT with gasoline. I guess you could get the duty cycle closer with adjustable fuel pressure, but that is an underhood adjustment just like a carb. Also, what if you had a 1/4 tank of E85 and added gas to it. I suppose that running the injectors at lower duty cycle on the street would be ok, I don't know.

Whaddya think?
 
Good point Larry. Haven't done the math, but may have to run dual injectors per cylinder.?? Holley system can do this but I would need to see if the second set can some how be controlled /enabled when running ethanol?
 
Good point Larry. Haven't done the math, but may have to run dual injectors per cylinder.?? Holley system can do this but I would need to see if the second set can some how be controlled /enabled when running ethanol?

I dunno about the ethanol thing, but I have heard that in fact many FI systems fire the injectors twice per cyl firing...

so why not do that??

just a comment, I know nothing.....:bonkers::censored:
 
,... BTW, is there some reason you are shying away from an intercooler? ........



My setup is a draw-through system I put together 20 years ago, and an intercooler presents some fireworks possibilities in the event of a backfire. TBI injectors (A 454 2bbl in this case) pose a bit more constraints on packaging versus PFI injectors, and a draw-through system was easier at the time. I've kicked around a few plumbing changes to allow an intercooler, but mod'ing the '69 has been eating up most of my free time the last couple years. (Pardon the wiring mess. I've still got a bit of instrumentation attached from the last tuning session.)

IM001508.jpg
 
Last edited by a moderator:
The Holley Dominator EFI can support 8 injectors wired sequentially with a 2nd set blended in batch fired, disabling the batch fire injectors when running pump gas. Right now, I am not thinking of generating the high hp that dual injectors could support. If I do this, something along the lines of what Mike has (9-10lbs of boost) sounds like more than adequate for my BB application.:amazed: I will have to bone up on turbo applications as this strategy unfolds. This could turn into a major project if I'm not careful:bonkers: :nuts:
 
The Holley Dominator EFI can support 8 injectors wired sequentially with a 2nd set blended in batch fired, disabling the batch fire injectors when running pump gas. Right now, I am not thinking of generating the high hp that dual injectors could support. If I do this, something along the lines of what Mike has (9-10lbs of boost) sounds like more than adequate for my BB application.:amazed: I will have to bone up on turbo applications as this strategy unfolds. This could turn into a major project if I'm not careful:bonkers: :nuts:

Rather than all that with the second set mechanicals, why not just fire the things twice or 3x? if like my car is batch fire, there is plenty of time to fire them at least twice in a given cycle...no?

seems easier to do a program change....no?

:confused::drink:
 
Top