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Discussion Starter #1
Hi!

First post on my.is :)

I have a question about AFR tuning on a '02 IS300: is the LTFT taken into account when running in open loop/WOT?

I saw unconsistent information about this...
Not taken into account?

Taken into account?

I plan to tune my car to run on E85 (way cheaper here in France) and that totally changes the approach...
(I do not plan to tune for hp but the answer might be out there so I posted in go fast stuff)

any thoughts?
 

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Hi!

First post on my.is :)

I have a question about AFR tuning on a '02 IS300: is the LTFT taken into account when running in open loop/WOT?

I saw unconsistent information about this...
Not taken into account?

Taken into account?

I plan to tune my car to run on E85 (way cheaper here in France) and that totally changes the approach...
(I do not plan to tune for hp but the answer might be out there so I posted in go fast stuff)

any thoughts?
All of this is conjecture. Until you decide what power range you are wanting.
 

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Discussion Starter #3
Let's be more specific then :)

My target is to keep my IS not far from stock, with the constraint of running on E85.
Running on 100% E85 or a mix (when no E85 station is found), means counting on LTFT to adjust, even on open loop.

In any case stock 250cc injectors are too small for ethanol.
First I plan to 330cc 2JZ-GE non vvti injectors. If AFR at WOT is kept correctly it might be sufficient, but I have to get a wideband to know that.
 

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Let's be more specific then :)

My target is to keep my IS not far from stock, with the constraint of running on E85.
Running on 100% E85 or a mix (when no E85 station is found), means counting on LTFT to adjust, even on open loop.

In any case stock 250cc injectors are too small for ethanol.
First I plan to 330cc 2JZ-GE non vvti injectors. If AFR at WOT is kept correctly it might be sufficient, but I have to get a wideband to know that.
First for E85 you need a stand alone. Special sensors, pump, and injectors.v"not far from stock" does not mean anything. Try a number for wheel horsepower. E85 you will need a lot of boost or a lot of compression.
 

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Discussion Starter #5
E85 is just to reduce fuel expenses (way cheaper here in France), my target in WHP would be 200 at max, staying NA for sure.

I want to keep all stock equipment, traction control and such
Moreover I have an emission test to pass.
 

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You realize that e85 is about 30% less potential energy than pump 91? I’m assuming you know that, since you’ve upped the injectors about 30% larger to make up for the difference. It’s more corrosive too, so you may need to upgrade the fuel line to ptfe or e85-safe rubber (does such an animal exist?).
 

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E85 is just to reduce fuel expenses (way cheaper here in France), my target in WHP would be 200 at max, staying NA for sure.

I want to keep all stock equipment, traction control and such
Moreover I have an emission test to pass.
You do not need E85 for that horsepower. It is a waste of time and money to use for your goal. Normal fuel will give you way better gas mileage.
 

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Discussion Starter #8
Let's do the maths :
91 gas: 1.45 €/L
E85 : 0.6 €/L
Annual miles : 5000 / (= 8000 km)
Fuel consumption : 12 L/100 km = 20 mpg
Annual fuel expense on 91 : 1400 €
Considering a +30% fuel consumption, fuel expense on E85 : 750 €

If conversion costs 1000€ (injectors, pump, wideband sensor. An ECU would increase this bill though): investment is profitable in 1.5 year...

I know that it is not the case in the US, and ethanol is only used for its benefits in high boost applications (octane rating and latent heat).
So it is a totally different mindset.

Here many people run small gasoline engines with cheap chinese piggybacks at 200€ or less that increase injection time or modify MAF sensor signal, coupled with an exterior temperature sensor for cold starts. With absolutely no care about injectors cc or fuel pump. The piggyback adds an arbitrary injection time correction, the ECU fine adjusts with fuel trims.
And for everyday life it works, for hundreds of thousands miles for many people, certainly because it is less of a problem to run lean on ethanol if injectors are maxed out.
Of course I often wonder if these people run their engine hard, not that much I think. Unfortunately, I do.

Moreover, about fuel lines let's be realistic: the proper way is to replace them but in real life chances of having a problem are very low. Starting from year 2k fuel lines and rubbers deal with ethanol with absolutely no problem. Moreover in Europe we have had ethanol mixed in gas (5 on 10% depending on the gas type) for a very long time and Toyota officially states that their cars are compatible with a 10% mix from 1998.
The only thing needed when switching to ethanol in real life is cleaning/changing fuel filter several times in the first thousand miles.

So in my case I just want to do a proper ethanol conversion that keeps stock engine behavior as far as possible.
That means injecting more, and my intial question meant "after changing the injectors with a cc ratio roughly equal to the higher flow needed, can I rely on the ECU for AFR fine tuning ?"
 

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Let's do the maths :
91 gas: 1.45 €/L
E85 : 0.6 €/L
Annual miles : 5000 / (= 8000 km)
Fuel consumption : 12 L/100 km = 20 mpg
Annual fuel expense on 91 : 1400 €
Considering a +30% fuel consumption, fuel expense on E85 : 750 €

If conversion costs 1000€ (injectors, pump, wideband sensor. An ECU would increase this bill though): investment is profitable in 1.5 year...

I know that it is not the case in the US, and ethanol is only used for its benefits in high boost applications (octane rating and latent heat).
So it is a totally different mindset.

Here many people run small gasoline engines with cheap chinese piggybacks at 200€ or less that increase injection time or modify MAF sensor signal, coupled with an exterior temperature sensor for cold starts. With absolutely no care about injectors cc or fuel pump. The piggyback adds an arbitrary injection time correction, the ECU fine adjusts with fuel trims.
And for everyday life it works, for hundreds of thousands miles for many people, certainly because it is less of a problem to run lean on ethanol if injectors are maxed out.
Of course I often wonder if these people run their engine hard, not that much I think. Unfortunately, I do.

Moreover, about fuel lines let's be realistic: the proper way is to replace them but in real life chances of having a problem are very low. Starting from year 2k fuel lines and rubbers deal with ethanol with absolutely no problem. Moreover in Europe we have had ethanol mixed in gas (5 on 10% depending on the gas type) for a very long time and Toyota officially states that their cars are compatible with a 10% mix from 1998.
The only thing needed when switching to ethanol in real life is cleaning/changing fuel filter several times in the first thousand miles.

So in my case I just want to do a proper ethanol conversion that keeps stock engine behavior as far as possible.
That means injecting more, and my intial question meant "after changing the injectors with a cc ratio roughly equal to the higher flow needed, can I rely on the ECU for AFR fine tuning ?"
!0% in gas here is normal. But if you go to straight E85. Which I have run on cars in the past. You burn two times more minimum.
Take it from someone who has tried a few times. But try if you want to try.
 
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