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will switching to e85 have any adverse effects if im tuned for 93 ?


rapture

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please help me subaru engine guru's i finally found a station nearby that has e85,but do i have to get another dyno tune now??

i currently have two tunes saved on my cobb ap one for dd at 15 psi.

and one more aggressive tune at 19 psi. both done at r/t tuning by andy.

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If you're asking if it will hurt your engine, I don't believe so. From what I understand it would be like running 100 octane race gas.

 

Anyone ignorant about fueling should NOT be posting about E85. This is atypical misinformation as it is actually potentially catastrophically wrong.

 

Not only is it NOT racegas, it is less energy by volume than 87 octane (or 89, or 91 or 93 or 100). Bigger injectors, MORE fuel/tune are what is generally needed to take advantage of e85 anyway (e85 will run injector duty cycles out much faster than gasoline because of the added volume requirement).

 

Do not do it! It will run lean and you will blow the motor. It is not gas. it is VERY different. You can not mix more than 30% into a tank of 93 without taking a big risk.

 

^THIS

 

EDIT: The reason ppl say e85 is "racegas" is because it does not knock. Higher octane/racegas resists knock.

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If you're asking if it will hurt your engine, I don't believe so. From what I understand it would be like running 100 octane race gas.

 

But if you want to take full advantage of the E85 (or race gas), then, yes, you'll need a tune for it. Not only that, but you'll need larger fuel injectors and a fuel pump that can keep up with them.

 

Do you have to get it dyno tuned? Nope. I'm pretty sure infamous1 does E85 tunes via email.

 

Cheers!

 

 

Wow, I am speechless.:eek:

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Seriously.

 

Unfortunately it might be some of the worst advice given in a long time.

 

A true recipe for disaster.

 

You cannot fill up any car with e-85 if it has not been properly set up for it. Not any car. It will destroy any motor, N/A or turbo. Brand does not matter. There is a lot to it, I am simplifying things. All you need to know is do not put e-85 in a normal gas car unless it has been set up for it. You could do a 25% mix on a N/A car and probably be fine. But I am not advocating this.

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ok, m sprank , thank you so much. so should i go to my dyno guy and have him make me a tune for e85? and if so how does he go about doing that without the car running on it at that time ? also so all i need to do this is bigger injectors? what size? and if i do run bigger injectors will it throw off my current maps?
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The state of Minnesota requires that all gasoline sold there be a 10% e85 blend. Pretty much all modern cars can accept a 10% blend. (A reason why an OEM tune runs rich no doubt). Auto mfr in the USA honor warranty of gasoline cars running up to a 10% e85-gasoline blend.

 

Comfortably advocate the use of 10% e85 in gasoline motors as a preblend (blended out of the pump). If not, I wouldn't advocate the addition of e85 to a gasoline car at all (without proper fueling/tune of course).

 

(As MSprank knows) In CA the e85 pumps are EMERGENCY YELLOW. They are specifically designed with extra steps involved in the fueling process to make the operator STOP and pay attention to what they are doing so that they do not fill a gasoline car with e85.

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ok, m sprank , thank you so much. so should i go to my dyno guy and have him make me a tune for e85? and if so how does he go about doing that without the car running on it at that time ? also so all i need to do this is bigger injectors? what size? and if i do run bigger injectors will it throw off my current maps?

 

We tune the car on gas first. Then we fill with e-85, adjust tune accordingly and begin retuning. Gas tune is used as baseline, then fueling adjustments are made for e-85 along with timing and boost changes.

 

Size of injectors is dependent on set up. Same with pump(s) required. You should discuss everything with your tuner and builder prior to making purchases/decisions.

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Run your tank down as low as you can, then fill up fully with E-85. If you are dyno tuning, you will need a base map from the tuner first... that way you can get from the gas station to the dyno. Once on the dyno, they can dial-in the tune.

I guess the other option is to show up with a 5-gallon jug (or two) full of E-85, then when you get there, fill the car up. I would not do that myself, your tuner should really be able to give you a base map.

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Thanks for setting me straight. Believe it or not, I have read a bunch about E85 but obviously wasn't paying close enough attention.

 

I've been quoted so my idiocy will stay visible but my post has been deleted.

 

I'll return to lurking and keep my mouth shut now.

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Pretty much all modern cars can accept a 10% blend. (A reason why an OEM tune runs rich no doubt)

 

Disagree with the bolded part. The OEM tune is rich simply because it is tuned that way. The OEM fueling, at WOT, simply targets rich ~10.5:1 mixtures. The reason for rich tuning is NOT to allow variation in fuel, as that is the purpose and function of the fuel trims. It is rich due to a desire of SOA to have a conservative, safe tune, and possibly for emissions reasons.

 

On an aside, I put E85 in my Wrangler at times. I've spoken to the guru of E85 (hotrod), and if interested in running E85 he says every tank add a little more E85. Start with 2 gallons per tank. Run the tank and if no CEL, go to 2.5 gallons per tank. Continue until you get a CEL, then back off to the last 0.5 gallon E85 increment and then you know where you can run safely. It should be somewhere around 3-4 gallons per tank but will vary. I haven't found my limit in the Wrangler but I might play with it some more. I'm expanding on what m sprank said, basically... it's possible but you need to be careful.. most modern cars will gradually tweak the fuel trims. Of course doing this without a tune you won't benefit from 2 of the greatest things about E85 - running more timing and running more boost (if FI). Still, there should be a noticeable torque gain without a tune. Proceed at your own risk but I can tell you that running 2 gallons per tank in any modern car really should be just fine.

My '05 LGT

My '07 Supercharged Shelby

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So the OEM tune is rich simply because it is? :confused:

 

Subaru likes to make sure their cars are down on power and get reduced gas mileage? There must be something I am missing. Arent OEM tunes designed so that owners can toss anything from watered down 87 to 10%e85 blends without having engine failure resulting in warranty work? Doesn't that mean that one of the reasons an OEM tune is rich is to easily allow for owner sillyness? Again, I must be missing something... (not sarcasm!)

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From an engineering perspective, any OEM tune will be rich for safety. There's an old saying about engineers trying to design for idiots... people that put 87 in their LGT come to mind when considering that.

 

Regardless of the reason, we all know OEM is richer than necessary.

lol
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So the OEM tune is rich simply because it is? :confused:

 

Subaru likes to make sure their cars are down on power and get reduced gas mileage? There must be something I am missing.

 

My take is it is rich for an added margin of safety and for emissions. It's only actually rich at WOT, and not most driving conditions. At cruise and idle it is just slightly rich of stoich and overall not really down on mileage significantly. I'm no authority on the matter... just my belief and I'm happy to change or add to it with a persuasive argument. ;)

 

Arent OEM tunes designed so that owners can toss anything from watered down 87 to 10%e85 blends without having engine failure resulting in warranty work? Doesn't that mean that one of the reasons an OEM tune is rich is to easily allow for owner sillyness? Again, I must be missing something... (not sarcasm!)

 

Absolutely, but most of that it is done with fuel trims. Sure, they probably dumb down timing slightly and may even make it little richer for that reason too (variance in fuel and user error) and boost can even be disabled by dropping IAM, but what you are describing is accomplished primarily by the long and short term fuel trims. And the fuel trims aren't part of any variation of the stock tune. What I'm saying is that the trims themselves aren't tune-able, for better or worse. Practically speaking, anyways.

My '05 LGT

My '07 Supercharged Shelby

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NO.... richer = worse emissions.

 

Disagree. It depends what particulate you are talking about. In Colorado we test for CO, NOx, and HC. They all have limits. Take a look at the emissions chart, below. Most modified Subies fail due to high NOx. (See this thread). Still think "richer = worse emissions"? True for CO and HC, but great for keeping NOx down. To fix a subie that is failing due to high NOx, consider richening the tune.

 

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My '05 LGT

My '07 Supercharged Shelby

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