Thread: E85 good or bad
08-20-2011, 05:15 PM #1
E85 good or bad
One of my customers asked the question below and rather than reply privately I thought it might be a worthwhile thread to start, the info is relative for all types of ECUs
"Do you have an E85 map for an fzr?
id like to try it out. e85 is like 3.50 or so a gallon "
E85 is a great fuel but it does come with some draw backs, some of these to follow.
1. Is it E85 all the time?????
The fuel you buy at the pump (In Australia anyway) is known as E85 but sold as "Bio Fuel"
Bio Fuel is actually anywhere from 85% Ethanol down to 70% Ethanol
So a perfect tune for one tankful will not match the next tankful.
You can mix it your self to gaurentee the same fuel each time but is it worth it.
2. Is there any gain????
The fuel is cheaper yes but you use significantly more of it , 35% (again depending on the blend) you would have to work that out depending on your local cost per gallon
Other things to consider.
A. Will your injectors be big enough for the 35% extra fuel
B. Will your fuel system be safe against the corrsive effects of the ethanol
C. Will your fuel tank be big enough considering you are going to be using 35% more fuel for the same distance
The good news
Used in the right application the performance gains are SIGNIFICANT
It all comes down to ignition timing
If your set up what ever it is has 22 or more degrees of ignition timing in it at full throttle then E85 will do virtually nothing, (small gains at best)
The max power ignition timing for a yamaha SHO engine is close to 27 degrees, more than that at full throttle and it wont make anymore RPM
slightly less than that will only lose a little bit of power.
So if you can get 23-24 degrees into your SHO engine on normal 98AUS/93USA octane fuel at 15 PSI (which you can) then why go to E85 as you might only pick up 50 more rpm at best
If you are running a turbo engine at a good compression ratio then if you are running that same 98/93 octane fuel then as you go up in boost the ignition timing would need to come back to suit
Approx 1 degree per 1 PSI you go up. (This obviously to prevent detonation) So a typical ignition figure for 25 PSI of boost on a Yamaha running 98/93 pump gas would be 13 degrees.
NOW, if I add E85 with its much higher octane rating I am able to get that 10 degrees back in to the engine and pick up a SIGNIFICANT amount of power.
I did this recently on a turbo FZR, the gain was around 500 rpm from memory, it was night and day.
So its all about context, if your engine is a dedicated race engine and you are allowed to use a race fuel such as MS109 then that will be overall much better, you carry less fuel for your race, you donít have to potentially upgrade your injectors, and you donít need to worry about the corrosion factor on your fuel lines or pump assembly.
You get the idea.
I am sure there will be plenty of other input on this so let the games begin
08-20-2011, 06:12 PM #2
Subscribing..going to be a great thread!!
I know some porsches in south florida making some big power on E85 conversions.
08-20-2011, 06:31 PM #3
As a race fuel only then yes, its great. Other than that, not so much.
08-20-2011, 07:11 PM #4
08-20-2011, 08:20 PM #5
The corrosion aspect is played up alot.. It really doesn't eat aluminum that much, the issues were cheap o-rings and gaskets. A friend of mine is having alot of success running his 555 BBC on E85 and 13:1 compression.. Here in Iowa we get huge rebates on it, and I was seriously looking at it as an alternative with some ID1000's.
08-20-2011, 08:43 PM #6
Theres a lot of talk about this on the board I'm on for my car. Good Topic - Subscribed.
08-20-2011, 10:05 PM #7
Just to add a couple things I've read up on about E85.
-E85 has a summer and winter blend. Summer is typically 85/15 ethanol/gasoline mix and winter blend is usually 70/30. If you are using this gas to race then it's a smart idea to purchase a gauge that will tell you what mixture the gas is.
-E85 is rated at 105 octane but because of it's cooling properties it acts almost like 120 octane fuel.
-like mentioned above, E85 has cooling features which gasoline doesn't.
08-20-2011, 10:23 PM #8
Well, as a side note, I'm wondering why nobody is running Meth injection yet here. I'm not talking about running straight Methanol. I mean a simple misting kit like what coolingmist sells. I use one on my turbo BMW and it essentially gives me 100 octane fuel from crappy 92 California gas basically letting my ECU go way higher on boost with pump gas. I don't run it all the time but when the occasional Corvette pulls up, haha.. well you get the point. It's just a small 1 gallon tank that mounts remotely and the Coolingmist System monitors flow and there is feedback to the tuner ECU to keep AFR right and keep you out of the dreaded advance...and pings. To put it simply: as a general rule with my car, 10 degrees advance at WOT is a bad thing....
08-20-2011, 10:51 PM #9
- Join Date
- Oct 2007
- Brisbane, Australia
I have a 205 ltr drum of both methanol and ethanol in the shed (for reasons other than putting in 1800 yamaha engines).
The biggest problem with them is that they are both very hydroscopic (they suck moisture from the air).
Is that the source of corrosion that scares most people???
08-21-2011, 06:30 AM #10
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