Everybody in this thread is correct in their own way. The tester is a nice quick way to see when a local station makes the switch to e70ish (lol) and the sensor would be great to have but only really necessary on a big build pushing the limits.

For me I would just watch my trims and call it a day. I also believe area47 knows his **** and from what I've read he is spot on. If someone doesn't like his style of commenting then just pretend he didn't post. There's no point in attacking him when he has contributed a lot of knowledge not to mention it completely de-railed this thread.

 

Sorry man, I tried but the you will see that he started to derail this thread at post 15, before that it was about the test method.

 

The original inline GM ethanol sensors used in the early flex fuel vehicles are not reliable.

E85 Seasonal Blend Changes:
Per federal (DOE) specifications E85 does change the % ethanol vs hydrocarbon by season. The purpose of this is to raise the Reid Vapor Pressure of the fuel for cold starts in flex fuel vehicles (FFV's)- this is done by increasing the % hydrocarbon (gas component) as colder temps are expected.

Here are the normal months changes begin to happen as one moves thru the seasons and the final blend % alcohol for Wisconsin's lattitude;

Sept 1st to Oct 31st - 78%
Nov 1st to March 31st - 70%
April 1st to May 15th - 78%
May 16th to Aug 31st - 83%

(% alcohol is stated in pure terms w/o denaturing gas-- thus the Summer E85 is 85% denatured ethanol but only 83.3% pure 200 proof booze). The months stated above will generally see changes happen near the first day of the month (except May and Sept) unless the weather is holding steady.

 

This is a good thread. Don't worry about it.

The only way to know for sure is to go right to the source. Some stations mix in the tank, some mix at the pump. My local stations mix in the tank

FINAL UPDATE UNTIL SPRING—THE ETHANOL CONTENT WILL MINIMIZE TO 70.364% AND NOT GO LOWER. I will email (God Willing) when we get close to Spring Blend (E78). Have a Merry Christmas!



S=Summer, SP=Spring, F=Fall, W=Winter ----# following is # of that season’s type loads –followed by % pure ethanol—followed by date/time of last load. **** means load soon (within 4 days)

Summer blend loads are 83.3% pure ethanol so as blended through tank inventories we will eventually hit 83.3% max.—generally by load # 3

As always- have the performance guys contact me direct for up to date status.



4 Corners- W2, 70.47%, 11/22 7:04 am

Cedar Grove- W 0.5, 74.88%, 11/3 11:52 am, UPDATE W1.5, 71.35%, 12/6 2:02 pm

Grand Chute- W3, 70.5%, 12/3 7:57 am

Howard- W3.5, 70.4%, 12/1 9:46 am

Kewaunee- W1, 72.526%, 11/5 12:33 pm

Little Chute- W2, 70.51%, 11/17 3:52 pm*****

Manitowoc- W2, 70.68%, 11/26 10:52 am

Mayville- W2, 70.88%, 12/3 10:44 am

Oostburg- W1.5, 71.465%, 12/3 8:25 am

Oshkosh Green Valley W3, 70.44% 12/1 7:32 am

Oshkosh South Park W3, 70.426%, 11/29 8:26 am

Plover- W2, 70.87%, 11/5 10:54 pm, UPDATE W3, 70.46%, 12/6 9:23 pm

Seymour- W2, 70.16%, 11/22 10:11 am

Sheboygan Falls- W2, 70.85%, 12/3 12:17 pm

Waupaca, W1, 72.46%, 11/5 11:26 am, UPDATE W2, 70.735%, 12/6 5:18 pm

Waupun, W2, 70.735%, 11/17 5:38 am*****

Wautoma- W2.6, 70.58%, 11/26 4:37 pm

Winneconne- W1, 72.424%, 11/5 12:40 pm, UPDATE W2, 70.71%, 12/6 2:27 pm

 

He is a LNF with no 5th injector and stock cams and a fairly aggressive tune boost wise so no more than 50/50 E-85 and gas mix before his car is dropping rail pressure like mad.

 

Thank you, I didnt think to check under his user name, I just assumed he was LSJ, I keep forgetting to differentiate between DI and SFI.

 

That kind of information is incredible. I need to organize something like this in my area.

 

Here is my latest test, my area has been around 87-90 lately. All I did was change my stoich to 9.8 in my HPT file. Then took the car to the dyno yesterday. My tuner showed that my ST and LT FT were still within 3-5 percent after jumping a little on the accelerator. So with just changing stoich from my winter blend 70 percent (10.2 stoich) to the summer blend (9.8 stoich) the car remained tuned. Didnt have to adjust my fuel trims on the dyno yesterday.



The car made 472 whp and 427 wtq on the E90. The cars BRFPS was running 70 psi into PE and dropped to 55 at WOT to 7000. I think my stock fuel pump is now my restriction. The injectors duty was 64 percent pull after pull. We consistently made in the 460 range. After seeing absolutely nothing better than 13 afr's we knew we messed with the brfps enough and de-tuned the boost controller to see afr's at a happy 11.5-12 range. At the boost setting to 24 psi dropping down to just over 20 my car was making 430 whp.


So the 20g was plenty capable of making much better numbers but Ryan at Gwatney Performance Innovation detuned 40whp to keep everything happy with the fuel I had on hand. I think with just a fuel pump I could see this car staying in the 470 range. Also I wanted to note that E85 is something very special. Even at 13 afr's there was absolutely no knock in any of the dozen or so runs we made in 100 degree heat.

My next tune session will be this fall, I will be bringing a new fuel pump and running the car on E70 when they decide to change over the mix in my area.

E85 is just incredibly fun to tune a car around.

 

my run from yesterday.

 

Damn kid. You be whoring that graph out! lol

 

You are right. Fixed, just hit on the e85 stuff instead.

 

Haha.. I'm just busting your stones. I really don't blame you one bit. I'd be plastering that bad boy all over the place too if I had a 470whp dyno sheet to flaunt.

On a side note touching on e85. One thing to keep in mind with e85 is that not only does the ethanol content change for different seasons, but it also changes from station to station, and even some stations hardly change the content at all. For example; the Mobil station I use to normally frequent for my e85 has never sold anything under 85% even in the dead of winter. I have however seen as high as 90% in July-August. On the other hand, a station maybe 45 minutes away from that station does in deed change the alcohol content but they do it at completely random times. I've tested fuel there with 70% alcohol at the same time of the year that the Mobil station was selling 90%, so it's really all over the damn place and it's a damn crap shoot half the time. I love e85, but sometimes it's really just a damn headache staying on top of.