Flex-Fuel Conversion?
Senior Member
Joined: 07-10-07
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From: West Palm Beach
I am refering to a NON DI COBALT. I said I dont know about DI, but on another car, all that needs to be changed is fueling applications (more or less, depending on top of car), and you need to tune for it.
Like I said, I don't think it will happen on these cars just because of how finicky the computers are. Plus, without the ability to just swap out injectors for huge ones...I just don't know how it could be accomplished on a DI motor that isn't designed for E85.
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Joined: 03-15-08
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From: Chicago...Land
you're talking about heavily modified cars, with much higher compression ratio's. This guy is talking about running it in his car for better fuel economy and a slight power bump. It doesn't work like that.
To run regular gasoline in an engine that makes comparable power on e-85, the compression would have to be so high that it would cause catastrophic detonation on 93 octane fuel.
Lifted this right off wikipedia: E85 consumes more fuel in flex fuel type vehicles when the vehicle uses the same compression for both E85 and gasoline because of its lower stoichiometric fuel ratio and lower heating value. European car maker Saab currently produces a flex fuel version of their 9-5 sedan which consumes the same amount of fuel whether running e85 or gasoline,[13] though it is not available in the United States. So in order to save money at the pump with current flex fuel vehicles available in the United States the price of E85 must be much lower than gasoline. Currently E85 is about 5-10% less expensive in most areas.[14] More than 20 fueling stations across the Midwest are selling E85 at the same price as gasoline.[15] E85 also gets less MPG, at least in flex fuel vehicles. In one test, a Chevy Tahoe flex-fuel vehicle averaged 18 MPG [U.S. gallons] for gasoline, and 13 MPG for E85, or 28% fewer MPG than gasoline.
To run regular gasoline in an engine that makes comparable power on e-85, the compression would have to be so high that it would cause catastrophic detonation on 93 octane fuel.
Lifted this right off wikipedia: E85 consumes more fuel in flex fuel type vehicles when the vehicle uses the same compression for both E85 and gasoline because of its lower stoichiometric fuel ratio and lower heating value. European car maker Saab currently produces a flex fuel version of their 9-5 sedan which consumes the same amount of fuel whether running e85 or gasoline,[13] though it is not available in the United States. So in order to save money at the pump with current flex fuel vehicles available in the United States the price of E85 must be much lower than gasoline. Currently E85 is about 5-10% less expensive in most areas.[14] More than 20 fueling stations across the Midwest are selling E85 at the same price as gasoline.[15] E85 also gets less MPG, at least in flex fuel vehicles. In one test, a Chevy Tahoe flex-fuel vehicle averaged 18 MPG [U.S. gallons] for gasoline, and 13 MPG for E85, or 28% fewer MPG than gasoline.
Senior Member
Joined: 03-05-09
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From: Des Moines, IA
As a serious conversation...
I'd be curious how much +/- the stock PCM is willing to adjust fuel pressure and IDC to hit target AFR before MIL's start to appear. I'd be willing to drop 1/4 of E85 in my car next fillup and see what it does. Car has a wideband so in theory it should dump in as much fuel it needs to achieve the target AFR. If it starts popping MIL's, then we know we need to do some PCM work. If the car eats 1/4 could try 1/2 tank... basically wean the LTFT's close to E85 as possible.
For a stock turbo'd car, I'd guess the fuel system has +30% fueling capacity left in it. Especially if HPTuners ever decides to unlock the fuel pressure tables for us. Beyond that who knows, I see figures dropped on various forums about our DI.
In the end to do it properly you NEED control in the PCM.
I'd be curious how much +/- the stock PCM is willing to adjust fuel pressure and IDC to hit target AFR before MIL's start to appear. I'd be willing to drop 1/4 of E85 in my car next fillup and see what it does. Car has a wideband so in theory it should dump in as much fuel it needs to achieve the target AFR. If it starts popping MIL's, then we know we need to do some PCM work. If the car eats 1/4 could try 1/2 tank... basically wean the LTFT's close to E85 as possible.
For a stock turbo'd car, I'd guess the fuel system has +30% fueling capacity left in it. Especially if HPTuners ever decides to unlock the fuel pressure tables for us. Beyond that who knows, I see figures dropped on various forums about our DI.
In the end to do it properly you NEED control in the PCM.
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Joined: 05-21-08
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From: Creedmoor, nc
As a serious conversation...
I'd be curious how much +/- the stock PCM is willing to adjust fuel pressure and IDC to hit target AFR before MIL's start to appear. I'd be willing to drop 1/4 of E85 in my car next fillup and see what it does. Car has a wideband so in theory it should dump in as much fuel it needs to achieve the target AFR. If it starts popping MIL's, then we know we need to do some PCM work. If the car eats 1/4 could try 1/2 tank... basically wean the LTFT's close to E85 as possible.
I'd be curious how much +/- the stock PCM is willing to adjust fuel pressure and IDC to hit target AFR before MIL's start to appear. I'd be willing to drop 1/4 of E85 in my car next fillup and see what it does. Car has a wideband so in theory it should dump in as much fuel it needs to achieve the target AFR. If it starts popping MIL's, then we know we need to do some PCM work. If the car eats 1/4 could try 1/2 tank... basically wean the LTFT's close to E85 as possible.
Without tuning it would be dangerous to run e85 - even running only 30% you are still going to be running dangerously lean.
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Joined: 10-12-08
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From: SE Michigan
I found this in a bulletin
Customer Interest in E85 Fuel
As the retail price of gasoline increases, some locations in the country are seeing price differentials between regular gasoline and E85 where E85 is selling for substantially less than regular grade gasoline. One result of this is that some customers have inquired if they are able to use E85 fuel in non-E85 compatible vehicles.
Important: Only vehicles designated for use with E85 should use E85 blended fuel.
E85 compatibility is designated for vehicles that are certified to run on up to 85% ethanol and 15% gasoline. All other gasoline engines are designed to run on fuel that contains no more than 10% ethanol.
Notice: Use of fuel containing greater than 10% ethanol in non-E85 designated vehicles can cause driveability issues, service engine soon indicators as well as increased fuel system corrosion.
Using E85 Fuels in Non-Compatible Vehicles
General Motors is aware of an increased number of cases where customers have fueled non-FlexFuel designated vehicles with E85. Fueling non-FlexFuel designated vehicles with E85, or with fuels where the concentration of ethanol exceeds the ASTM specification of 10%, will result in one or more of the following conditions:
Lean Driveability concerns such as hesitations, sags and / or possible stalling.
SES lights due to OBD codes.
Fuel Trim codes P0171 and / or P0174.
Misfire codes (P0300).
Various O2 sensor codes.
Disabled traction control or Stability System disabled messages.
Harsh / Firm transmission shifts.
Fuel system and / or engine mechanical component degradation.
Notice: Use of fuel containing greater than 10% ethanol in non-E85 designated vehicles can cause driveability issues, service engine soon indicators as well as increased fuel system corrosion.
If the dealer suspects that a non-FlexFuel designated vehicle brought in for service has been fueled with E85, the fuel in the vehicle's tank should be checked for alcohol content with tool J 44175. If the alcohol content exceeds 10% , the fuel should be drained and the vehicle refilled with gasoline - preferably one of the Top Tier brands.
Repairs to non-FlexFuel vehicles that have been fueled with E85 are not covered under the terms of the New Vehicle Warranty.
A complete list of GMs FlexFuel vehicles can be found in this Service Bulletin, or at www.livegreengoyellow.com.
so basically any e85 conversion would be at your own risk. Do the research and if you go through with it, don't cut any corners.
Customer Interest in E85 Fuel
As the retail price of gasoline increases, some locations in the country are seeing price differentials between regular gasoline and E85 where E85 is selling for substantially less than regular grade gasoline. One result of this is that some customers have inquired if they are able to use E85 fuel in non-E85 compatible vehicles.
Important: Only vehicles designated for use with E85 should use E85 blended fuel.
E85 compatibility is designated for vehicles that are certified to run on up to 85% ethanol and 15% gasoline. All other gasoline engines are designed to run on fuel that contains no more than 10% ethanol.
Notice: Use of fuel containing greater than 10% ethanol in non-E85 designated vehicles can cause driveability issues, service engine soon indicators as well as increased fuel system corrosion.
Using E85 Fuels in Non-Compatible Vehicles
General Motors is aware of an increased number of cases where customers have fueled non-FlexFuel designated vehicles with E85. Fueling non-FlexFuel designated vehicles with E85, or with fuels where the concentration of ethanol exceeds the ASTM specification of 10%, will result in one or more of the following conditions:
Lean Driveability concerns such as hesitations, sags and / or possible stalling.
SES lights due to OBD codes.
Fuel Trim codes P0171 and / or P0174.
Misfire codes (P0300).
Various O2 sensor codes.
Disabled traction control or Stability System disabled messages.
Harsh / Firm transmission shifts.
Fuel system and / or engine mechanical component degradation.
Notice: Use of fuel containing greater than 10% ethanol in non-E85 designated vehicles can cause driveability issues, service engine soon indicators as well as increased fuel system corrosion.
If the dealer suspects that a non-FlexFuel designated vehicle brought in for service has been fueled with E85, the fuel in the vehicle's tank should be checked for alcohol content with tool J 44175. If the alcohol content exceeds 10% , the fuel should be drained and the vehicle refilled with gasoline - preferably one of the Top Tier brands.
Repairs to non-FlexFuel vehicles that have been fueled with E85 are not covered under the terms of the New Vehicle Warranty.
A complete list of GMs FlexFuel vehicles can be found in this Service Bulletin, or at www.livegreengoyellow.com.
so basically any e85 conversion would be at your own risk. Do the research and if you go through with it, don't cut any corners.
Senior Member
Joined: 03-05-09
Posts: 1,028
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From: Des Moines, IA
Thats fine, and a common E85 tuning misunderstanding. When you tune w/E85 you still shoot for whatever AFR's you would for gas. You just have to shoot a lot more fue (~30%ish +/-)l to hit the same AFR is all.
If you don't believe me, just cruise around some of the aftermarket wideband makers sites and read the FAQ's
As I said earlier, without full control of the PCM there isn't a whole lot of point to this. You might get away with 1/4 tank but whats the point.
If you don't believe me, just cruise around some of the aftermarket wideband makers sites and read the FAQ's
As I said earlier, without full control of the PCM there isn't a whole lot of point to this. You might get away with 1/4 tank but whats the point.
Only problem is the computer is going to try to achive 14.7:1 - gasoline stoich. Stoich for e85 is closer to 9.765:1. Can you see the problem here? Without tuning it would be dangerous to run e85 - even running only 30% you are still going to be running dangerously lean.
Without tuning it would be dangerous to run e85 - even running only 30% you are still going to be running dangerously lean.
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Joined: 05-21-08
Posts: 1,006
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From: Creedmoor, nc
Thats fine, and a common E85 tuning misunderstanding. When you tune w/E85 you still shoot for whatever AFR's you would for gas. You just have to shoot a lot more fue (~30%ish +/-)l to hit the same AFR is all.
If you don't believe me, just cruise around some of the aftermarket wideband makers sites and read the FAQ's
As I said earlier, without full control of the PCM there isn't a whole lot of point to this. You might get away with 1/4 tank but whats the point.
If you don't believe me, just cruise around some of the aftermarket wideband makers sites and read the FAQ's
As I said earlier, without full control of the PCM there isn't a whole lot of point to this. You might get away with 1/4 tank but whats the point.
From what Ive been reading, it should be tuned via lambda readings, not converted to afr readings.
New Member
Joined: 03-06-20
Posts: 1
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From: Wisconsin
Colbalt SS/Turbo Charged
Has anyone converted their SS/TC to use E85-E100? This is purely out of curiosity because it'd be interesting to see what kind of torque the LNF can produce using E85.
Would our standard fuel system handle the E85? What about the injectors and fuel pumps? How would the tuning be handled? Is there a way to install an ethanol sensor to switch tunes when it detects the use of E85?
Would our standard fuel system handle the E85? What about the injectors and fuel pumps? How would the tuning be handled? Is there a way to install an ethanol sensor to switch tunes when it detects the use of E85?
Wow, that was an 11 year old post. Not sure why your friend would even need meth since E85 has a cooling effect anyway. Bet that saab runs good as they basically have a lsj engine anyway if it's a 4cyl.
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