flexfuel +/- tune hp tuners?
flexfuel +/- tune hp tuners? so...dumb question.....hp tuners lets me enable or disable flexfuel in my 07.....is this all i need to run E85, and if so what are the benefits and negatives about it. would it just run off the low octane settings in hp tuners?
Nope.
The tune gives you the option, but the rest of the fueling system is not set up for flex fuel. Specifically, we don't have the sensor that detects the percentage of alcohol in the fuel. The stoichiometric AFR changes rather drastically between gas and E85. You'd be running extremely lean if you just dumped E85 in the tank. I'm not sure if the hardware is equipped to deal with the corrosive effects of alcohol, but maybe.
You can reset stoich, but then you may also be maxing out the stock injectors to add sufficient fuel (near redline @ WOT anyway).
Fuel mileage will also suffer when running E85 because it is a less energetic fuel.
I had tried a tank of 92 octane 10% ethanol, vehicle ran OK, but consistently 6% lean.
The tune gives you the option, but the rest of the fueling system is not set up for flex fuel. Specifically, we don't have the sensor that detects the percentage of alcohol in the fuel. The stoichiometric AFR changes rather drastically between gas and E85. You'd be running extremely lean if you just dumped E85 in the tank. I'm not sure if the hardware is equipped to deal with the corrosive effects of alcohol, but maybe.
You can reset stoich, but then you may also be maxing out the stock injectors to add sufficient fuel (near redline @ WOT anyway).
Fuel mileage will also suffer when running E85 because it is a less energetic fuel.
I had tried a tank of 92 octane 10% ethanol, vehicle ran OK, but consistently 6% lean.
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Joined: Jul 2007
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From: Reading, Pennsylvania
I would never run E85 even if I had a vehicle that could. As mentioned above, you'll lose fuel economy using it, plus there are a whole other set of issues to it not necessarily including those with the car, but that's a whole different debate.
Nope.
The tune gives you the option, but the rest of the fueling system is not set up for flex fuel. Specifically, we don't have the sensor that detects the percentage of alcohol in the fuel. The stoichiometric AFR changes rather drastically between gas and E85. You'd be running extremely lean if you just dumped E85 in the tank. I'm not sure if the hardware is equipped to deal with the corrosive effects of alcohol, but maybe.
You can reset stoich, but then you may also be maxing out the stock injectors to add sufficient fuel (near redline @ WOT anyway).
Fuel mileage will also suffer when running E85 because it is a less energetic fuel.
I had tried a tank of 92 octane 10% ethanol, vehicle ran OK, but consistently 6% lean.
The tune gives you the option, but the rest of the fueling system is not set up for flex fuel. Specifically, we don't have the sensor that detects the percentage of alcohol in the fuel. The stoichiometric AFR changes rather drastically between gas and E85. You'd be running extremely lean if you just dumped E85 in the tank. I'm not sure if the hardware is equipped to deal with the corrosive effects of alcohol, but maybe.
You can reset stoich, but then you may also be maxing out the stock injectors to add sufficient fuel (near redline @ WOT anyway).
Fuel mileage will also suffer when running E85 because it is a less energetic fuel.
I had tried a tank of 92 octane 10% ethanol, vehicle ran OK, but consistently 6% lean.
TECH Fanatic
Joined: Jul 2006
Posts: 1,732
Likes: 0
From: K.C.
can you tune for e85? yes. you have to add a percentage of fuel. IE: more fuel. i takes more to run at the same level of "pump gas" you can leave the timing table as it sits, just have to increase the maf settings to add a touch more fuel. or ve side, which ever you choose. and richen up the pe side as well to compensate for it.
can you tune for e85? yes. you have to add a percentage of fuel. IE: more fuel. i takes more to run at the same level of "pump gas" you can leave the timing table as it sits, just have to increase the maf settings to add a touch more fuel. or ve side, which ever you choose. and richen up the pe side as well to compensate for it.
. Since we don't have the alcohol sensor I doubt that the alcohol tables will be active, that probably means multiplying the values in the OL Gas and PE tables by 1.5.Not sure why you would touch the MAF, airflow isn't changing, just the amount of fuel you need to add to the existing airflow.
Anyone know how the NBO2 would react? I think it would switch normally in closed loop since the amount of oxygen in the exhaust should be similar.
TECH Fanatic
Joined: Jul 2006
Posts: 1,732
Likes: 0
From: K.C.
maf settings would have to change to add fuel in the part throttle range. you set up the wideband lambda side to read the normal afr. you don't need the alky sensor or any other fancy crap to do it. you do need a wideband to monitor things. and also a good understanding of tuning as well. there is an evo here that put down over 500 on e85, and a civic that did 604 on e85.
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Yeah, you can make good power using E85 - with an octane rating that varies from 100 to 105 you can run higher compression/boost than with pump gas.
This is a bit of an academic discussion anyway, long term use of E85 in a vehicle that wasn't designed for it is a losing proposition.
I am not personally in favor of fudging the airflow numbers to adjust for AFR differences such as this, I'd rather just tell the injectors flow XX% more fuel and leave the airflow numbers alone (assuming that the VE and MAF tables were already tuned for gas).
Anyway, enough said.
Merry Christmas.
This is a bit of an academic discussion anyway, long term use of E85 in a vehicle that wasn't designed for it is a losing proposition.
I am not personally in favor of fudging the airflow numbers to adjust for AFR differences such as this, I'd rather just tell the injectors flow XX% more fuel and leave the airflow numbers alone (assuming that the VE and MAF tables were already tuned for gas).
Anyway, enough said.
Merry Christmas.
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