E85 fuel ethanol content seasonal changes

"E85 fuel blends change content seasonally just like all gasolines blends change with the seasons. This seasonal change in blend for E85 is primarily to improve cold weather starting, where the changes in gasoline during cold weather is to improve cold weather starting. In the summer months, gasoline must be blended to reduce vapor lock and to reduce evaporative emissions.

The recommended dates for changing E85 fuel blends are listed in a chart in the E85 handbook on page 22, which is in the "E85 Fuel Specification" tab.
The Volatility class specifications are broken down on page 10.

Volatility class 1 --- minimum ethanol 79%
Volatility class 2 --- minimum ethanol 74%
Volatility class 3 --- minimum ethanol 70%




As you can see each region has a different start date and recommendation for seasonal blends depending on local weather climate.

Here on the high plains east of the rockies in Colorado we run the class 1 fuel blend from mid June -- mid Sept, run class 2 fuel from mid Sept -- mid Oct and run the class 3 fuel blend from Mid Oct -- mid April, then back to the class 2 blend from mid April to mid June. The standard only specifies a minimum ethanol content, vendors can run higher ethanol content if it is economical. If it is cheaper for the fuel blender to add more he can. Ethanol content is bottom line driven by local weather conditions, and cold starting problems for local drivers just a gasoline blends are modified to give easier starting in cold weather.

In the Southern part of Texas they would never go to a class 3 blend, and in Wisconsin, they would only have the class 1 blend for about 2 months in the summer. In Florida they would be on class 1 almost all year long and in North Dakota and Wyoming and Montana, they would be on class 3 almost all year long. "
 
I know the above is specific to the US, but might give some insight into seasonal changes for this biofuel. Australia seems to be pretty 'new' to the world of 'E' compared to other countries as there is not much local info around for it.

Interesting note:
Here are some comparisons of stoichiometric fuel mixtures for different fuel blends: 
======== stoichiometric AFR ===== max power rich AFR 
Petrol ---------- 14.7:1 -------------------12.5 
100% E-85 ------- 9.73-9.8:1 ------------- ~ 9:1 - 8:1 
100% fuel ethanol - 9:1 ------------------- ~ 7.2:1 
 
Well, there is no wondering why there are significant gains with the factory ECU and pig rich running under boost with this stuff.

^^ Well going on that as a guide, class 2 should be all we'd need to see.
 

Still struggling with getting these tunes setup, due mainly to available time, and the need to go back and revise everything between sessions. I settled on a 40/60 mix for the E tune and used the old 98 performance 550 tune as a baseline for the ULP98 tune on 650's, with a bit of extrapolation to get started.
One thing I can tell you at this time is the E tune just blows the 98 tune out of the water.
Here's a couple of thoughts, so feel free to pick them apart if you want:
One thing seems certain so far with all this..how bad our ULP fuel quality really is, and I'd dispute some of the premium is actually 98, particularly vortex seems questionable. At one point I thought I had a bad batch of bio-flex, but turns out it was the ULP.
The stock ECU is running overtime correcting Ign values on 98 as a result of the pump fuel RON value. This is evidenced by the smooth power delivery on an E mix, even 10%, amoungst other things.
I have found the ign curve will accept as much as 3-4deg additional advance across the rev range, and even more around 1500-2000 rpm. MBT is not difficult to achieve, and PCP at 10deg ATDC has a dramatic effect on power output on the 3SGTE, particularly at higher boost - higher revs.
Quite apart from the substancial benetifts of the improved RON, the addition O2 content and latent heat of vaporisation of the E is having a marked effect on combustion temps, and exhaust flow. This needs to be looked at with a view to some accurate assessment of temp changes. Be interesting to see how E would perform if it were mist sprayed pre turbo.
I suspect exhaust gas flow velocity vs exhaust gas temp is considerably higher, and would be benefitial where a stock ct26 was concerned, probably increasing useable boost pressure and rpm  before any chocking of the exhaust flow across the turbine wheel.
On a gt28/71 I'm seeing a bit of boost creep that wasn't there before, though these 28/30 series are suseptable to that in some cases without an EWG.
A change to a good EBC should solve the problem in part.
Anyone playing with the stock setup on E mixes, you need at least a good 3" exhaust and a good aftermarket IC..low charge temps are one of the keys to making more power. A pod filter on the AFM just doesn't cut it, you need to plumb the intake down into the side vent, as close as you can get it, or put the pod filter in the stock intake box, if that's possible.
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 

I've got a straight 3" exhaust, apexi pod on the AFM and an uprated side mount with puller fan running all the time - on top of the CT20b. I noticed giving it a mad dash in 3rd gear that I crept to 17psi but stayed constant around the 16psi mark. On normal 98RON I'll always be sitting around the 14-15psi mark...sometimes will touch 16psi on the colder nights.
 
I may run down Marsden way tonight and get another couple of litres and throw it in. I might drop the ratio a bit and go 5L E +35L of 98 as last time was more like 25L 98 and 6L of E.
 
Any side effects to take into consideration on our old and tired fuel systems? Well those of us that still have a stock setup? Any chance of seals and hoses getting shagged by the ethanol?

I was getting my wheels aligned on the weekend by a guy who races a BMW R-Spec M3 and we were talking about the whole E85 thing (both straight and as a mix with high-octane ULP). He tried running his M3 on it a while ago and after seeing how much water it absorbed and what that was doing to his oil, he decided to give up... and he also said a rep from one of the fuel companies told him "I wouldn't run my own car on the stuff!"
 
He said that anyone who runs this without having all their fuel lines and seals changed to 100% E-compatible one is going to end up in a world of hurt a bit further down the road.
 
Now please don't flame me if you're a "believer". I'm just reporting what I was told... by a guy who's opinion I respect.
 
 

yes I do agree with that, all the reading I have done has said that... But like I say, better to be safe then sorry even if it isn't the case...

^^ Haven't seen any problems so far, and I'm running stock lines. The car sits all week so I've kept a close watch on things. I'd expect a stock pump to suffer at some point, but I think that would be with continued use over time, rather than sooner, at those rates.
With moisture absorbtion, your virtually at the mercy of the servo to store the bio-flex as regulated, though I'd expect some small level, due to condensation, would be considered acceptable? maybe consider it as water injection lol...long as it doesn't effect the tank. But then water in ULP is not uncommon.
Same with any oil contamination, the MR2 turbo's suffer badly from fuel contamination due to the mega rich stock AFR's under boost, and this E mix is making for more combustible ratios. Where tuning is concerned, there's no issue.
I'll be keeping an eye on that though, I've switched to Penzoil 10w/40 syn, with more frequent changes, so I'll drain it after getting the tune completed and see how it is.
 
 

I think water absorption is just as much an issue when the e85 is in the car's tank as it is at the servo.
My wheel alignment guy said he was staggered by how much it soaked up... and what really freaked him out was that when he checked his oil (fully synthetic race grade) after using the e85 just for a single race it had gone from being "as slippery as teflon to seriously grabby." Then he said, "imagine what it's doing to you engine if you can't even slide it between you fingers!?!"
EDIT: After abandoning the e85, he's taken to buying 105RON fuel by the drum .

I just put some more in my car. I think my fuel gauge is on it's way out. Put in 20L of 98 when I was on 1/4 exact - didn't get me anywhere near the 3/4 mark which it should have. Put in a few L of E. Gave it a bit of a squirt in 3rd and straight up to 16psi by 4000rpm.

MuMan

Anyone playing with the stock setup on E mixes, you need at least a good 3" exhaust and a good aftermarket IC..low charge temps are one of the keys to making more power. A pod filter on the AFM just doesn't cut it, you need to plumb the intake down into the side vent, as close as you can get it, or put the pod filter in the stock intake box, if that's possible.

 

I refuse to run straight ULP "swill" now, be it 98 or otherwise - car just feels lethargic on it. It seems like I'm pushing the 'stock' exhaust to its limits at the moment as well. 
So whats the reasoning behind needing a "GOOD" 3" exhaust when running E and how restrictive is the stock b pipe (looks pretty ****)? I have a Garage Fukui SPL Departure II Pro (3.35") exhaust ready to go on and what kind of gains will I expect when running E mix with the CT26 on this exhaust? (I already have a Berk 3" CC DP btw)
 
Also, I thought intake temps before the turbo were not as critical as on an N/A as the intercooler will cool down the intake charge anyway after the turbo? My pod filter is pointed towards the side intake vent with some kind of fabricated AFM adapter, but it doesn't look ideal.
Would it be worth making some kind of "shield" around the pod filter block it off?