Please Do Not Run E-85 on Stock Injectors.

[Jn2]

I'm gonna have to disagree with ya OP. Just because you don't know how to tune it safely and reliably doesn't mean it can't be done. Sure not so much with a GT350 im turning 7,500 plus, but since your post title paints such a broad stroke.

Plenty of cars running E85 on stock injectors on 15-16's.

It has nothing to do with "tuning it properly". There is nothing you can do to tune out the 97% injector duty cycle. 97% duty cycle is 97% duty cycle. Only way to lower this is to run a lower ethanol percentage like e70 so less fuel is needed or you end up letting it lean out when it does hit 100% and you run out of fuel.

Once you hit 100% duty cycle the injectors will go static and you will lose any and all control over fuel delivery.

Even at 97% there is still some, although very marginal, control over fuel delivery, the injectors still have a small pause when spraying. The problem is it's a 3% window, should anything happen that requires more fuel, say, air gets colder in the winter or you rev higher then you will hit that 100% and you will no longer be able to achieve your commanded lambda.

How much will this affect the car? Well it depends, e85 does have more knock resistance than 93 so if you command .88@wot and run out of fuel it could lean out to .90 or higher, depending on the tunes aggressiveness this may not be enough to cause any KR but that does not mean it is safe to run it this way.

Most pumps don't always give you e85, they can go as low as e70, which could give the injectors some extra head room and keep IDC lower, but e85 with a ethanol percentage of 85% will tax the stock system close to max.

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[Terminator2]

I'm gonna have to disagree with ya OP. Just because you don't know how to tune it safely and reliably doesn't mean it can't be done. Sure not so much with a GT350 im turning 7,500 plus, but since your post title paints such a broad stroke.

Plenty of cars running E85 on stock injectors on 15-16's.

You are not understanding this. This is a physical limitation (injector mass flow rate) not able to be changed by tuning. I'm on the stock intake manifold and was at 97% injector duty cycle which is too high. There are plenty of cars on the edge of possible disaster from running lean at wide open throttle.

 

[Need4Speed15]

You are not understanding this. This is a physical limitation (injector mass flow rate) not able to be changed by tuning. I'm on the stock intake manifold as was at 97% injector duty cycle which is too high. There are plenty of cars on the edge of possible disaster from running lean at wide open throttle.

I appreciate your findings and sharing the info.

My questions are: Lund has been providing the Flex Fuel tune since before last x-mas. Do you think they didn't check the duty cycle on these tunes before they started offering them? Do you think there wasn't any R&D that went into developing these tunes? Do you think Lund is knowingly putting tunes out there that are on the dangerous edge?

The Flex Fuel tunes have been out for let's say 10 months. We haven't seen any failure or problems as a direct result of these tunes. Lund has been in this game for a long time and I trust their experience and knowledge.

Not trying to stir the pot, but genuinely interested in your thoughts.

 

[16s550]

I just want to be sure it's safe to run flex fuel or should I stop. Lots of mixed responses

 

[GSLSE20B]

I just want to be sure it's safe to run flex fuel or should I stop. Lots of mixed responses

You are fine to run straight e85 . With a big manifold and headers on tested 90% my stock injectors couldn't keep up to 8k .

 

[18psi]

Hey GSLSE20B,
What was your IDC when car actually leaned out?
I ask because on other platforms I've tuned, I've seen 115%-120% reported by the ecu, which we all know is impossible, before the car actually started to lean out and was physically maxed out of fuel. There was clearly a buffer of some sort.

I'm not saying that 97% IDC isn't concerning, but OP sure is making lots of general statements and contradicting lots of well known tuners (just from what I read, I don't tune mustangs so I don't have a dog in this race)

 

[Terminator2]

I appreciate your findings and sharing the info.

My questions are: Lund has been providing the Flex Fuel tune since before last x-mas. Do you think they didn't check the duty cycle on these tunes before they started offering them? Do you think there wasn't any R&D that went into developing these tunes? Do you think Lund is knowingly putting tunes out there that are on the dangerous edge?

The Flex Fuel tunes have been out for let's say 10 months. We haven't seen any failure or problems as a direct result of these tunes. Lund has been in this game for a long time and I trust their experience and knowledge.

Not trying to stir the pot, but genuinely interested in your thoughts.

The only thing I can think of is my car is making a little more power than the average one they are tuning.:shrug: I would like to see the logs of those on E-85 on a Lund flex tune and stock injectors. Sean from AED won't do flex tunes without LU47s being added to the car so I'm sure he's seen exactly what I am seeing on my car.
FWIW I doubt you will find anyone who is self tuned on E-85 running stock injectors.

Someone with a Lund flex tune on stock injectors and full E-85 please post up screen shots of max IDC in your logs.

 

[mustang_guy]

Hey GSLSE20B,
What was your IDC when car actually leaned out?
I ask because on other platforms I've tuned, I've seen 115%-120% reported by the ecu, which we all know is impossible, before the car actually started to lean out and was physically maxed out of fuel. There was clearly a buffer of some sort.

I'm not saying that 97% IDC isn't concerning, but OP sure is making lots of general statements and contradicting lots of well known tuners (just from what I read, I don't tune mustangs so I don't have a dog in this race)

You must have tuned subarus.

 

[Terminator2]

Hey GSLSE20B,
What was your IDC when car actually leaned out?
I ask because on other platforms I've tuned, I've seen 115%-120% reported by the ecu, which we all know is impossible, before the car actually started to lean out and was physically maxed out of fuel. There was clearly a buffer of some sort.

I'm not saying that 97% IDC isn't concerning, but OP sure is making lots of general statements and contradicting lots of well known tuners (just from what I read, I don't tune mustangs so I don't have a dog in this race)

Yikes once 100% happens the injectors go static, fueling control is lost and usually the car leans out almost immediately. I honestly don't feel comfortable with anything 90% or over its just cutting it too close for comfort in my opinion. I've got no dog in this race either I'm only tuning my mustang no one else's I'm trying to warn people. Say someone fills up and it's E-90 instead of the E-70 they were logging and getting 90% duty cycle on. Well now they are at 100% due to increased fuel mass flow demand.

 

[Terminator2]

Seems like it would be an issue for a GT350 car. Someone with GT350 and LTs should datalog and post their findings. Though I trust Lund.

GT350s have the same injectors as us so yes you definitely want upgraded injectors to run E-85 in a GT350. Even on 93 or any pump E-10 I would imagine they are close to 85% injector duty cycle based off their output vs our motor and their rev limit.

 

[18psi]

You must have tuned subarus.

haha, yep. a few other platforms too (mitsu evo, turbo miata's) but the theme seemed to be similar among most of them: you could dip deep into the 120%+ reported IDC and only then did you start to lose control of fuel

Yikes once 100% happens the injectors go static, fueling control is lost and usually the car leans out almost immediately. I honestly don't feel comfortable with anything 90% or over its just cutting it too close for comfort in my opinion. I've got no dog in this race either I'm only tuning my mustang no one else's I'm trying to warn people. Say someone fills up and it's E-90 instead of the E-70 they were logging and getting 90% duty cycle on. Well now they are at 100% due to increased fuel mass flow demand.

Same here, anything past 90% and I start recommending bigger injectors. But in this case, at least my opinion from observing all these flex fuel tunes/results, it seems that stock or near stock is just "safe" enough to get by at sea level, and if you're at elevation you're likely fine altogether.

But I like this discussion and your findings so I'm subscribing to this thread

 

[16s550]

So what injectors should I get when I cross the road of gt350 intake and Paxton or procharger

 

[GSLSE20B]

The only thing I can think of is my car is making a little more power than the average one they are tuning.:shrug: I would like to see the logs of those on E-85 on a Lund flex tune and stock injectors. Sean from AED won't do flex tunes without LU47s being added to the car so I'm sure he's seen exactly what I am seeing on my car.
FWIW I doubt you will find anyone who is self tuned on E-85 running stock injectors.

Someone with a Lund flex tune on stock injectors and full E-85 please post up screen shots of max IDC in your logs.

what is your "EQ RATIO ERROR" at your max injector DC

 

[mustang_guy]

haha, yep. a few other platforms too (mitsu evo, turbo miata's) but the theme seemed to be similar among most of them: you could dip deep into the 120%+ reported IDC and only then did you start to lose control of fuel


Same here, anything past 90% and I start recommending bigger injectors. But in this case, at least my opinion from observing all these flex fuel tunes/results, it seems that stock or near stock is just "safe" enough to get by at sea level, and if you're at elevation you're likely fine altogether.

But I like this discussion and your findings so I'm subscribing to this thread

20 bucks says you're vladi on nasioc.

 

[Terminator2]

So what injectors should I get when I cross the road of gt350 intake and Paxton or procharger

ID1000 or ID1300 on E-85 depending on power level.

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