Flex Fuel related Q
TECH Fanatic
Joined: Aug 2003
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From: Tranås, Sweden
Originally Posted by BlackHawk T/A
What's going to happen to Runn's car then?
And how long would you say it would take an F-Body to go to crap from running E85 through it daily?
He is past the 2 year mark so far.
And how long would you say it would take an F-Body to go to crap from running E85 through it daily?
He is past the 2 year mark so far.
I might change the fuelpump next year to a bigger one... pics of the old one will be posted.
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Joined: Oct 2005
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The sensor measures the dielectric constant of the fuel, with the conductivity increasing with the percentage of alchohol present. Last I heard the sensor is around $500 + or -. There's no reason that the sensor wouldn't be treated like any other enrichment table. It might even be possible to use a sensor on a modified IAT table to enrichen the mixture with alchohol...assuming you could get the sensor's signal into the computer. The IAT sensor is a NTC thermistor - resistance based and I think the fuel sensor is voltage based on the GM.
Fuel systems have to be compatible with 10% ethanol by law, there is no reason to assume that at say 40% they would fall apart. It doesn't make sense that GM would only put in parts compatible with the minimum.....or does it? You may have trouble with some fuel pumps at 85% alcohol. High alcohol % attacks the epoxy that hold some of the motors together.
Fuel systems have to be compatible with 10% ethanol by law, there is no reason to assume that at say 40% they would fall apart. It doesn't make sense that GM would only put in parts compatible with the minimum.....or does it? You may have trouble with some fuel pumps at 85% alcohol. High alcohol % attacks the epoxy that hold some of the motors together.
Originally Posted by Runn
Actually E85 is in most cases at least 5% more effícient than gasoline at the same lambda value. It produces more exhaust gas for a give weight of fuel air mix giving higher average cylinder pressures inspite of lower EGT's. With streight E85 in a properly tuned car its good for about +5% power / torque increase. At proper mixture you actually are releasing more energy in the cylinder due to the higher quantity of fuel you can burn. Peak combustion pressures are actually lower for ethanol than for gasoline but the cylinder pressures stay higher longer, so you have more (longer) crank angle that is usable by the engine. This lower peak cylinder pressure also helps with detonaton control.
Theorethically, the gain is 5% just by switching fuel. 350 hp X 5% = 15 hp, plus what can be gained from timing.
Theorethically, the gain is 5% just by switching fuel. 350 hp X 5% = 15 hp, plus what can be gained from timing.
Launching!
Joined: Mar 2004
Posts: 231
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From: Exton, Pennsylvania
I don't think you will see better mpg with E85, even when taking into account the higher compression the E85 engine will be able to run. I think Runn's point was that with an engine tuned for E85, since it's stoich is a lower number that the E85 engine can run more fuel in the cylinder, ultimately yielding more power than it's gasoline counterparts. Pretty much the same principal for any alcohol or nitro motor out there.
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Joined: Aug 2003
Posts: 1,130
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From: Tranås, Sweden
Originally Posted by 97BlackLT1TA
hmmm... Ive always been told the opposite. Ive taken classes for learning about fuel and such because of my job and they have always said that you wont get as good as MPG's. Im not saying your wrong just saying that ive been told different for years. But even if it is less efficient i would still run it here because it is ALOT cheaper, cheap enough to still save money over regular. Thanks for the info
