thesoundandthefury

iTrader: (3)

So far from what I've gathered in my studies of E85 fuel, they have determined that the optimum A/F ratio for this stuff is 8.9:1. This is a far cry from the perfect A/F ratio of regular gasoline. What I'm wondering is: is the software in an OBDI PCM for a 95 LT1 flexible enough that the parameters could be changed to optimize the use of E85? I'm kicking around some ideas on how to maintain the power increases that the 105 octane can produce, but burn it at the rate it was designed for so that mpg is better. Can it be done?

Runn

Dont know but lots of people in Sweden runs their LS1:s on a mix of 50% E85 and 50% gas without problems...

Phoenix64

iTrader: (3)

I ran my L36 on E85 for about 4-5 months. The stuff is great. I was maxing 43lb injectors on 8psi of boost.

My fuel mileage fell off almost exactly 30% even bumping the timing. It would work better on a higher compression engine.

As far as compensating, if you plugged in the proper sized injectors, the computer would probably sort it out. About 30% bigger.

Runn

I wonder the injectors on my 98 would be enough

Phoenix64

iTrader: (3)

Stock injectors wouldn't be enough. My stockers were 19lbs.

GuitsBoy

iTrader: (4)

Probably not.

You'd need 30# injectors. 30# injectors run at about 40# on our four bar fuel rail pressure. Thats just about 38% more injector over stock. However this doesnt guarantee that the ethanol wont eat through your plastic and rubber fuel components.

Runn

30# you say... IŽm going to try 50% ethanol next time í need fuel. Where have you heard that ethanol is eating the plastic, All gas in sweden already has 5% ethanol.

masterdill

iTrader: (2)

Has anyone with HPtuners tried adjusted the "Stoich AFR" setting which adjusts the global AFR, to work with E85?

horist

Adjusting the stoich AFR won't do much (prolly much more harm than good) w/the stock O2 sensors...
they're accurate at 14.7:1 or so... as you go further away they are less accurate at detecting AFR (they only measure stoich)

now you put E85 in that apparently needs to run at 8.9:1 ... the O2 sensor would be useless... it'd try to pull more and more fuel... and put you at maxed out LTRIMs

Then your WOT tables would be messed up (or rather open loop and PE tables)...

If 8.9:1 is the AFR that's ideal for E85 then it'd be more than just changing the stoich value... your best bet would probably be to tune the car for open loop only at the proper AFR

Not sure about ethanol eating plastic... I think the cars made to run on E85 have some different stronger type plastic to prevent premature wear... but at the same time the midwest (USA) has had signs that say "may contain up to 10% ethanol" on the pumps for as far back as I can remember...

brianmf

The O2 sensors would still work. They don't understand AFR, they only understand rich/lean. If you are using regular or E10 the stoich AFR is ~14.7:1 (as you well know) and when the O2s are switching, this is the AFR it is indicating. When you are using E85 (AFR 8.9:1), the O2s will still work, switching between rich/lean. It's just that the point they are switching at is 8.9:1. You have to know what fuel you are burning to properly interpret the information the O2 sensors are providing.

Bearing this in mind, changing the stoich AFR value in the computer is exactly the correct thing to do AFAIK. This informs the computer how much fuel to inject based on airflow. The O2s should act normally provided the VE table is correct. I do think that an E85 conversion(even an E85 only conversion, not FFV) would require more than just changing the stoich AFR; stuff like spark curves come to mind.

HTH

horist

I'm VERY curious on this.... can you provide any further info?

from my knowledge ..... Narrowband O2 sensors are made to be accurate at 14.7:1 ... (epa) ... so if these sensors can swifch at 8.9:1 ..... post up

Runn

Lambda 1 is always Lambda 1 no matter what you drive your car on, the o2 sensor doesnŽt care if the AFR are 14,7 or 8.9... it measures the available o2 in the exhaust gases.

I am increasing the E85 everytime i fill my tank and are adjusting the VE table every time.
Of course the timing will have to be changed, But iŽl wait until the VE is tuned i for 100% E85.

WS6FirebirdTA00

iTrader: (33)

so if we ran this stuff we woudl be sucking up fuel 30% faster, so the gas saving wouldnt really even be there? right? power wise, i assume this will give the car a little more kick, but how much more

horist

^^^ i think it depends on the cost of E85 where you are at....

for me... I don't know of a single station that sells it..... only time I've even seen a gas station that sold it was when I was on the hot rod power tour... driving through bufu Illinois

so for myself.... running E85 isn't economical.... however... what D_Run posted is interested.. and I think I understand..... and If I understand correctly... switching to E85 (if it's readily avail to you) really shouldn't be that hard...

Runn

The price for gas here is over 12Sek and E85 costs under 8Sek so for me there is a lot of money to be saved.
But i have get bigger injectors or the car is going to go lean.(tips on where to buy?)

WS6FirebirdTA00

iTrader: (33)

we just got it in charlotte and its 2.69 a gallon, regular is 2.89 a gallon, definatly not worth it unless we run out of regular gas again lol

Steel Chicken

iTrader: (3)

http://www.e85fuel.com/index.php

lots of info. It needs to be at LEAST 30% cheaper to break even, since you will burn 30% more to get the same power as gas. It has a much higher octane rating though, so you can add more timing and compression.

maxgee

iTrader: (5)

I have a turbo set up with hptuners for the tuning. I have 42lb SVO injectors which translate to about 48 on ls1 cars with 58psi. At 8psi I'm at 80% DC, I assume I don't have big enough injectors to go full boost. I want to experiment some with e85, if I keep boost to 5 and under I assume I use E85 with no problems?

crb99ws6

iTrader: (7)

If you are at 80% duty cycle on gas then you will be over 100% on e85

98turbls1

iTrader: (17)

I would go to 60lb injectors...