Can I use a mix of E85 and 91 to get higher octane without tuning?

[horizontalkev]

The highest octane around here is a joke, 91. Can I safely use half 91 and half E85 to make me I think roughly 97ish octane without tuning? Bigger fuel lines, T28 turbo @17psi thanks

 

[gieri002]

You can mix it, you just have to make sure your ethanol content is the same, or the lambda will change much like it does from winter to summer blends.

However, you would not want to do this without tuning. You would end up running lean. I had to add 13% more fuel with the e85 blend to achieve the same afr I had when running straight pump gas. Think of how much more fuel a car uses when running e85, hence the bigger injectors and pump.

 

[schalk35]

Why not just use toluene?

 

[horizontalkev]

So basically its beyond what I want to do at the moment Im too lazy . I have a 255 fuel pump and bigger lines and aeromotive fpr and fuel rail. Idk the injector size though

 

[bradikus7]

So basically its beyond what I want to do at the moment Im too lazy . I have a 255 fuel pump and bigger lines and aeromotive fpr and fuel rail. Idk the injector size though

Are you seriously? That's like I was taking to a guy about his Honduh, bought a new cam for it but knew nothing about it.

 

[horizontalkev]

Are you seriously? That's like I was taking to a guy about his Honduh, bought a new cam for it but knew nothing about it.

I bought the car with the mods done already. I know my parts.

 

[gieri002]

So basically its beyond what I want to do at the moment Im too lazy . I have a 255 fuel pump and bigger lines and aeromotive fpr and fuel rail. Idk the injector size though

Ha, exactly. You NEED a tune or you will destroy your engine!

 

[horizontalkev]

Why not just use toluene?

I search it before and some say its bad, although I know most fuel companies add toulene to increase octave so im not sure.. And the other remaining people say, use race gas. We don't have that around here either

 

[clipto]

You can run 1-2 gallons of e85 to a full tank of pump gas, you can't use half and half without a tune. I use do it when i had a maxed setup on a small 16g back in the day. I can tell you its rather pointless and a waste of money, sure u rajse oct a little.but going to grab a.gallon of e85 everytime u get gas is a waste of gas. Just need save up for a tune with ecmlink honestly. Please update your profile of your performance parts. If you just have a t28 then u dont need any gas mixtures. Get fmic w/ 1g bov that will help reduce intake temps and help reduce knock if there is any. Get a walbro 255 to help for fuel. Save up for injectors and ecmlink, and your set. I hope you got wideband and 3 inch exhaust then your all good. But yea keep boost low dont waste time adding gallon e85 its rather pointless. Its sunny go change your spark plugs. Ngk bpr7es gapped to .028. Happy boosting.

 

[clipto]

I use 93 octane pump gas. Should I be using 91? I haven't done much research on this. So just a quick question.

Definitly use the 93 oct higher is always better. I wish we had 93 oct they got 94 oct in canada. Just think oct number as the higher it goes the less knock your motor will have. Eventually get a tune on 93 oct see what u can do.

 

[DropSomeMoney]

Thanks. I appreciate the quick response. Sorry to the op for butting in.

 

[TopGun8818]

This is a very interesting topic as I have seen people doing this at the track with good success. I've talked to the guys from ATP turbo when I see them at Sonoma Raceway during wednesday night drags. They have ran the mix on their evo with a good decrease on their time and under hood temp. One of the guys explained that a lot of times shops discourage people from doing a mix because it's potential business they are loosing on a new meth/e85 setup to install on the customers car. They ran the mix for multiple sessions with no issues. The guy even had spare e-85 in the trunk he said I could have and mix correctly for me. However, knowing very little about the mix I kindly turned down the offer. After getting home I did some research and found out people have had good success with it along with bad. I'm guessing the bad is mostly due to people not doing the correct mix on it.

 

[92 GSR-4]

You MUST tune for E85 mix. If you were to run E85 alone, you would have to increase fuel by almost 50%! Mixing in E85 with gas is dangerous if you do not tune for it because you will actually be leaning out your fuel mix. The more E85 you mix in your gas, the more you actually need to "richen" up your fuel to keep it "stoich".

Take a look at this page: e85fuel [ECMTuning - wiki]

 

[habitatguy187]

I used to do this on my old car with nothing to tune with, just had a logger. The 1g ecu targets 9.5:1 afr under boost, which is uber rich. I used to mix 6 gallons of 93 to 2 gallons of e85 and definitely noticed and smelled a difference. The ecu compensated with fuel trims and my o2 still always read dead rich under wot pulls.

 

[horizontalkev]

Im wondering what the guy before me had the car tuned for. I don't have and never had contact with the previous owner so I have no idea what he's done other than its a six bolt swap with T28 turbo@18psi, MAF-T,FMIC, TiAl BOV, rewired walboro 255 fuel pump with steel braided fuel lines, bigger intake pipes, aeromotive fpr, crappy narrowband, greedy(I think) fuel rail, NGK BPR7ES, just installed new NGK spark plug wires. Also came with some obd2 adapter for a palm that came with car (for some type of logging)

 

[bastarddsm]

With a completely stock car you could get by with probably E50, because the stock maps are so rich, the probem is, the Ethanol, wants waaaay more timing. So you'd have to do that.

 

[horizontalkev]

So I was researching a little and saw people were using aviation fuel, 100LL avgas.. I call the municipal airport 5 miles from me and they sometimes sell "waste" fuel for around 2.50/gallon. They have some now I can pick up. Better to use as a mix or just as bad as E85 without a tune? I do realize the 100LL is leaded.

 

[bastarddsm]

100LL is roughly equivlent to conventional 110 racefuel, as far as octane goes. It has like 2 times as much tel in it tho. It's low lead by aviation standards. I've also found on carburated apps it likes to run a jet size or two leaner than pump gas. I was. Running it in a 350 aircooled 4 stroke that only pinged when really hot.
2 gallons in a full tank would definatly fight light to minor detonation. But it will kill your cat and 02 sensor.

Try swapping in a set of br8es plugs.. the standard style ones not the projected bpr8es... its possible that might cure your knock issues.

 

[horizontalkev]

Im not using it to fight detonation, well I don't think so Atleast.. According to my "torque" app its not detecting knock. But id feel safer using higher octane fuel because Im not going to 100% believe what torque says. The 100LL gas here I was told will have anywhere up to 3% lead, is that a lot? And its $5.80/gallon

 

[Pipnorcali]

I have a simalur setup n run 3 gallons of pump 100 or Sunoco 104 unleaded with my 91
The pump 100 oct is near the track and 104 Sunoco can be bought at auto parts stores in 5 gal. Jugs
I've ran up to 20-22 psi with no probs.

 

[slo335i]

This guy knows. I ran e85 on my mazdaspeed 3 and know first hand what u can do with it.
Just think of it like this. If you want more power u have to double your fuel. If you just add 2-3 gallons to fill the tank you aren't going to notice a diff. You need a TUNE for e85 for it to be effective.

E85 might be cheaper than race gas however you have to pump double the amount to get the power. With q16 for instance you might pay 6$ port gallon but your using smaller injectors and pump. To each their own tho e85 will blow your motor if u don't know your shit.

You MUST tune for E85 mix. If you were to run E85 alone, you would have to increase fuel by almost 50%! Mixing in E85 with gas is dangerous if you do not tune for it because you will actually be leaning out your fuel mix. The more E85 you mix in your gas, the more you actually need to "richen" up your fuel to keep it "stoich".

Take a look at this page: e85fuel [ECMTuning - wiki]

 

[hotrodssnova]

I have mixed e85 and gas at 50-50 mix and had to retune the car. Idle went super lean and car would barely stay running. I took my laptop with me that day just in case. At that ratio, a retune is a must.