Im new to E85 .. What is that exactly..

[rikdrt1]

I read somewhere that some exhaust was tested at 91-94octane .. to have some 5HP gain,a nd 15HP gain with E85 ?

im a bit of a newbie about fuel but how would a car like this - with toyota recommendations to use premium.. how is it even possible to use E85 ? waht exactly is that ?

maybe its just some b.s. --but trying to understand this. i know some Turbo cars use E85 .. but not sure why either.

?? whats the 3min answer to this ?
thanks

[cgrey]

[Sasquachulator]

Special ethanol/gasoline blend.

Do not use. Engines need to actually be certified to use it. You cant use unless your engine says it can (usually the vehicle would be referred to as E85 compatible or Flex Fuel)

AFAIK its NOT the same as 91-94 octane gasoline. I think those ones have at most 10% ethanol blended in to achieve higher octane ratings.

[Hawaiian]

Originally Posted by rikdrt1

I read somewhere that some exhaust was tested at 91-94octane .. to have some 5HP gain,a nd 15HP gain with E85 ?

im a bit of a newbie about fuel but how would a car like this - with toyota recommendations to use premium.. how is it even possible to use E85 ? waht exactly is that ?

maybe its just some b.s. --but trying to understand this. i know some Turbo cars use E85 .. but not sure why either.

?? whats the 3min answer to this ?
thanks

Here's the skinny

e85 is a fuel that is primarily Ethanol, a very high octane fuel derived primarily from corn, or sugarcane. It is mixed with standard petroleum based gas and other ingredients (detergents to clean your engine etc) to create a form of gas that cars can use to burn.

Ethanol is very high octane (I forgot if it's 108 or 103, I'm tired) and burns more cleanly than gas, however, it also takes more of it to create the same amount of power (about 30% more).

This is the reason your stock vehicle cannot run on e85 without a tune (brz/frs only, some other cars e85 will eat up hoses, injectors, and fuel pumps). After a remapping of your vehicle, more fuel will be pumped in to make up for the loss of power, and give you more, however, at a certain point your injectors will max out, and you need to upgrade those for bigger gains (turbo implementation).

Hope that helps.

[chuy21]

Originally Posted by Sasquachulator

Special ethanol/gasoline blend.

Do not use. Engines need to actually be certified to use it. You cant use unless your engine says it can (usually the vehicle would be referred to as E85 compatible or Flex Fuel)

AFAIK its NOT the same as 91-94 octane gasoline. I think those ones have at most 10% ethanol blended in to achieve higher octane ratings.

If his car is tuned for it (or her plans on getting tuned) why can't he use it?

[2gnt2wrx]

Originally Posted by chuy21

If his car is tuned for it (or her plans on getting tuned) why can't he use it?

There is a huge misunderstanding on here as to why a "stock" brz/frs can't use E85.

It can't be used on a stock tune or the settings in the cars engine computer from the factory. These settings can be adjusted by a "tuner... think... visconti here". The tuner will have to re-scale your injectors back 30% in order for the engine to run properly. What this will do is adjust your afr or air fuel ratios back to where they need to be, in order to idle/accelerate properly.

The other benefit of e85 is the higher octane rating. This will allow the tuner to advance the engines ignition timing which will result in more power.

Hope this helps

[Draco-REX]

Originally Posted by 2gnt2wrx

There is a huge misunderstanding on here as to why a "stock" brz/frs can't use E85.

It can't be used on a stock tune or the settings in the cars engine computer from the factory. These settings can be adjusted by a "tuner... think... visconti here". The tuner will have to re-scale your injectors back 30% in order for the engine to run properly. What this will do is adjust your afr or air fuel ratios back to where they need to be, in order to idle/accelerate properly.

The other benefit of e85 is the higher octane rating. This will allow the tuner to advance the engines ignition timing which will result in more power.

Hope this helps

He has to increase the injector duty cycle, no decrease it. Ethanol caries a lot of oxygen with it so you need more of it to hit the proper air/fuel ratio (Stochiometric). Normal fuel requires around 14 lbs of air for every lb of fuel. E85 requires only 9 lbs of air for every lb of fuel. Since the amount of air that can pass through the intake (Volumetric Efficiency) doesn't change, you have to add more fuel.

OP: Ethanol is actually the same alcohol you drink. Essentially you'd be running your car on moonshine. The big difference (and why you don't want to drink E85) is because it's only 85% Ethanol and 15% Gasoline.

A tune is needed for a non-flex fuel car to use E85 because of what I outlined above.

Another interesting thing is that E85 isn't always E85. The mix varies depending on region and expected monthly temperatures. Ethanol doesn't mix with air as readily as gas at lower temperatures. So in the colder month the mix can get as low as E70. That's why, while E85 can have an Octane rating between 105 and 110, most tunes for it tend to plan around an Octane rating of only 100 or so to handle variances in mix. (Flex Fuel cars have a sensor that can determine the Ethanol/Gasoline mix and adjust fueling accordingly).

But it's the high octane rating and the air-cooling properties of alcohol for less money than gasoline that makes E85 so attractive to forced induction applications. The extra ignition stability and the way alcohol takes heat out of the incoming air helps prevent pre-ignition (knock). That's why the turbo kits you see for these cars can only hit about 10psi on gasoline, but then you have Don running around on 20psi using E85.

Now why isn't E85 used everywhere if it's so good? Lots of logistical, political, and ecological reasons. Suffice it to say, we'd have to rebuild and/or double our infrastructure for moving liquid fuels around, politicians would have to stop demanding we use corn to make Ethanol, and at present it costs more energy to get a gallon of Corn Ethanol in your tank than Gasoline and the best source (cane sugar) won't grow reliably in the US.

At present E85 is a failed non-diesel Bio-Fuel for the masses. But it is a great race fuel and as long as it looks good on paper it will be available in cities near rail lines for a while to come.

[2gnt2wrx]

There is no "increase/decrease" IDC option. You actually have to scale the injectors back... like on my old sti, I had 1200cc injectors.... I had to scale them to 800 something in order to get it to idle properly on E.

[Draco-REX]

Originally Posted by 2gnt2wrx

There is no "increase/decrease" IDC option. You actually have to scale the injectors back... like on my old sti, I had 1200cc injectors.... I had to scale them to 800 something in order to get it to idle properly on E.

Being able to idle on large injectors is a separate issue. If you want to talk semantics, you can't "scale back" injectors either. Injectors always have the same flow rate at the same fuel pressure. You control how much fuel gets injected by controlling how long they are open, that's called the Injector Duty Cycle.

The fact remains that you need to pump about 30% more fuel into the engine for E85 than Gasoline, not less. By increasing the amount of fuel being injected into the engine, the IDCs go up. Larger injectors are needed for high horsepower applications because more fuel is needed.

If you went from 1200cc injectors on gas to 800cc injectors on E85, you had around twice the injector needed for your application on pump gas.

[TheRipler]

Originally Posted by Draco-REX

If you went from 1200cc injectors on gas to 800cc injectors on E85, you had around twice the injector needed for your application on pump gas.

He's talking about scaling in the ECU with the same 1200cc injectors. Tell the ECU that the 1200s are 800s, and it will increase the pulse width to add 33% more fuel to compensate for E85.

[Draco-REX]

Originally Posted by TheRipler

He's talking about scaling in the ECU with the same 1200cc injectors. Tell the ECU that the 1200s are 800s, and it will increase the pulse width to add 33% more fuel to compensate for E85.

Ahh. I see. That makes more sense.

[kanundrum]

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