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Discussion Starter #1
I live in Edmonton, Alberta, Canada.
I can get my hands on 94 octane fuel from a husky/mohawk. the only thing is that it may contain up to 10% ethanol.
Could this pose as a problem to my engine build when building a high compression setup?
 

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Discussion Starter #3
ya that's what some of the boys have been telling me because of it's latent energy. The thing though is that it will allow me to put pm7 or p29 pistons in my d16z6.
 

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Here in the states, we've got 93 oct @ the pump...the catch- we've got notices on all pumps saying the fuel you're about to use MAY contain UP TO 10% ethanol. I think you'll be fine running that...just get it tuned on that fuel if that's what you'll be running.
 

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Discussion Starter #5
yep i'm thinking that's what i will be running. hopefully it's not to much of a crutch
 

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WBO2's read in Lambda, not AFR. That nifty 14.7 or 12.5 etc. AFR you get on your dispay is a programmed conversion from a lambda reading.

That said, and without getting into lenghty detail:

Lambda is constant, regardless of fuel used, it is essentially the inverse of AFR. AFR is fuel dependent, Lambda is not.

Therefore if you tune to lambda (the funny little greek symbol that looks like an upside down v with a tail), the plus or minus 10% ethanol in your gasoline is irrelevant. If you tune via 14.7 stoich AFR for gasoline, and introduce the plus or minus 10% ethanol, your readings are skewed.
 

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Discussion Starter #10
okay so lets see if i got this right.
Your saying a stoichiometric mixture of pure gasoline and oxygen is 14.7 but the ethanol has a different stoichiometric mixture ratio. So because of this if i try to tune my afr i will actually be running a lean or rich mixture because ethanol requires a different amount of oxygen to completely burn. But if i tune using the lambda, which senses precise readings of how much oxygen is in the exhaust stream, i will get a better tune.
Am i understanding you correctly?

Hence the need for a wideband sensor eh. I almost forgot to include that in my pricing list.
 

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no, if your wideband setup is configured for stoich gasoline. tune for 14.7 if its setup for ethanol then the afrs will change. E10's stoich is 14.13 afr if your wideband is setup for ethanol. tune for 14.7-15s for idle and cruising. and high 12s mid 13s for wot.

that fuel will help your build. ethanols latent heat properties will help keep the temp of the combustion down along with the air intake charge.

for high compression this is good. you could also get a lower temp thermostat to keep the engine cooler. you can make more power on an engine that is overall more cooler than one that runs hotter.
 

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Discussion Starter #13
no, if your wideband setup is configured for stoich gasoline. tune for 14.7 if its setup for ethanol then the afrs will change. E10's stoich is 14.13 afr if your wideband is setup for ethanol. tune for 14.7-15s for idle and cruising. and high 12s mid 13s for wot.

that fuel will help your build. ethanols latent heat properties will help keep the temp of the combustion down along with the air intake charge.

for high compression this is good. you could also get a lower temp thermostat to keep the engine cooler. you can make more power on an engine that is overall more cooler than one that runs hotter.
The reason the combustion temperature will be kept down is a bad thing though. The ethanol has a lesser amount of latent energy compared to gasoline.

If gasoline stoich is 14.7 and ethanol stoich is 14.13 and you have up to 10% ethanol blended gasoline wouldn't you want to tune for slighty lower than 14.7? More like 14.6 to accomodate for the ethanol? Or do you want to run a little leaner during idle and cruising?

Also why so low for wot? Just for safety's sake or do you have a different reason?

What is the stock setting for the sytem to go into open loop and what is a good throttle position setting when tuned to go into open loop? What considerations do you have to make when choosing the throttle position % when changing over to open loop?
 

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The reason the combustion temperature will be kept down is a bad thing though. The ethanol has a lesser amount of latent energy compared to gasoline.

If gasoline stoich is 14.7 and ethanol stoich is 14.13 and you have up to 10% ethanol blended gasoline wouldn't you want to tune for slighty lower than 14.7? More like 14.6 to accomodate for the ethanol? Or do you want to run a little leaner during idle and cruising?

Also why so low for wot? Just for safety's sake or do you have a different reason?

What is the stock setting for the sytem to go into open loop and what is a good throttle position setting when tuned to go into open loop? What considerations do you have to make when choosing the throttle position % when changing over to open loop?
15-low 16s are fine for idle if you can get it to idle correctly. just talk to your tuner. cruising id go for low 15 mid 14's and any load or wot i would go for low 13's. all depends on what you have in your setup.

if the pistons are domed. the chance of detonating is higher than that of a less domed or flat top piston. the quench becomes significantly smaller on a domed piston setup.

it depends on how the wideband is setup. if its setup for gasoline and ur using ethanol you still tune for the 14.7AFR.

also the latent heat thing is a good idea because it cools down the air charge thus making air intake denser, so more air per volume = more power to be had. also cooler air charge has an even less chance of detonating than it being hotter.

low as in what? 12-13's are fine for NA, too lean and itl get too hot. the ecu does not compensate at wot. it uses the predefined parameters of fuel and ignition. the O2 sensor is not used at WOT.
rich is a good and bad thing. too rich you cant make the power, mpgs suck, you wash your cylinders and fouls up shit. just a tad bit rich is ok as it keeps the combustion cooler, its there to prevent a knock.
 

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Discussion Starter #15 (Edited)
15-low 16s are fine for idle if you can get it to idle correctly. just talk to your tuner. cruising id go for low 15 mid 14's and any load or wot i would go for low 13's. all depends on what you have in your setup.

if the pistons are domed. the chance of detonating is higher than that of a less domed or flat top piston. the quench becomes significantly smaller on a domed piston setup.

it depends on how the wideband is setup. if its setup for gasoline and ur using ethanol you still tune for the 14.7AFR.

also the latent heat thing is a good idea because it cools down the air charge thus making air intake denser, so more air per volume = more power to be had. also cooler air charge has an even less chance of detonating than it being hotter.

low as in what? 12-13's are fine for NA, too lean and itl get too hot. the ecu does not compensate at wot. it uses the predefined parameters of fuel and ignition. the O2 sensor is not used at WOT.
rich is a good and bad thing. too rich you cant make the power, mpgs suck, you wash your cylinders and fouls up shit. just a tad bit rich is ok as it keeps the combustion cooler, its there to prevent a knock.
I don't believe the ethanol blend would actually cool the intake charge. It would just be a cooler combustion. Which would aid in keeping the engine cooler but would not produce as powerful an explosion as straight 94 octane gasoline.

Your o2 sensor sends back voltage readings to determine lean or rich conditions. With a stock it will only read lean and rich but with a wideband it will read just how lean and just how rich the mixture is. Can't you just adjust the mixture so that your ecu's target combustion is a slightly leaner one according to your lamda.

I know the ecu does not compensate for sensor readings when at wot. It goes off predetermined charts. that is referred to as open loop. 12-13:1 just seemed a little rich to me. I was just wondering your logic behind it. If it would actually increase power or if it was merely a safety margin.

Your saying that with any load it will go into open loop?
 
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