Benja

Hey guys,

Have had a good run on E85 so far, tune is dialed in to 11.9-12.0 from bout 4k onwards.
For the initial swap I filled the car with 20L of E85 from a near empty tank, did about 50km and started preliminary tuning, once that tank emptied I filled up with more E85, tune leaned out due to the higher amount of eth as expected.
Fine tuned to suit, and has been fine on that tank for the past fortnight.
Took the car out to check some stuff on Monday night and suddenly it's 0.5 richer from about 140 load onward, around 11.5-11.7, did a boost leak test last night and other than the turbo seals leaking slowly due to it being cold it was fine.

Would this be indicative of Pump gas still in the mix? This has only happened since I got down to 1/4 tank.
No knock or anything else, load/boost difference are still as per normal.

Cheers.

JohnBradley

iTrader: (30)

Yeah it is most likely closer to E70 for that level of AFR change. But E70 still seems adequate for most combinations.

Benja

Ok thanks for that Aaron,
So a rough guide is 0.5 change afr = ~70ish%?

Have you ever seen it just richen up when getting toward the bottom of the tank with no other influencing factors?
Bearing in mind this is my first full tank of E85 only thats been through it.

I remember you posted a while back that you wouldn't count on it being pure until two full tanks have been passed, but figured I was close enough.

one4

this is the only thing i dont like about e85... the content varies. my car is tuned to be running a 11.9-12.0 afr also, but ive seen my wideband read as high as a 12.5 on some tanks and as low as a 11.2... most of the time its spot on but here and there it happens.

also yes if there is pump in the mix, it will be rich, if ur on pump and have a little e85 you will run lean

for example, i have only switched to pump one time since ive been on e85. When i did, i had 1 gallon of e85 in the tank and like 5 of 91oct... i was hitting a 12.1 afr on my pump map. sketchy!!!!! then when i switched back to e85, i still had like 1.5-2 gallons of 91 in and the rest was corn... i was hitting a 10.9

its best to have a pure mixture before. i ran a few tanks before driving hard to be safe.

Benja

Yeah thanks for that.
Must be some 93 floating around the tank still.
Suprising when I've run probably 13 gal. through the car and there would've been lucky to be 1.5 gal of 93 left in there.

skiracer

iTrader: (1)

Watch this video where i add 12.4 gallons of E85 to my 14 gallon tank which had 1.6 gallons of 91 octane in it previously

http://www.youtube.com/watch?v=wsWZVrdpSRI

Night479

is the a home made ethanol gauge or can i get that somewhere/write up that i can make one myself????

Night479

nevermind searched found it!!

jackbenimbo

iTrader: (1)

i need to get one of these =)