E85+91 Octane = 93 octane

[oehawks3]

For those of you that do not have access to 93 octane, have you tried doing a 30/70 mix to increase the octane to 93? Does anybody know if this is safe? A lot of BMW guys do this with their Cobb AP.

 

[DAS_STIG]

 

[oehawks3]

Yes, yes it is.

 

[RjRacing]

No its not. Octane readings don't raise by adding ethanol. Octane ratings depend on the amount of isooctane and heptane in the fuel, the ratio of each give us the octane rating. Introduction of ethanol also changes the amount of oxygen molecules in the mixture, it requires more volume of fuel to create the same ignition but as a result it runs cooler and is less prone to detonation. You cannot convert E85 to an octane rating though as it does not have the same chemical makeup that octane is rated at.

 

[Stage2Sasquatch]

However you can tune for specific blends of E85 and Pump fuel

 

[DAS_STIG]

Yes, yes it is.

No. They probably do a 30/70 mix because someone found out thats what the fueling system can support in terms of fueling requirements (you will need to use more fuel as someone previously explained if you increase the ethanol content) as well as what ethanol content the parts were designed to handle without corroding. They are basically making e35, not 93 octane fuel. I am not sure, maybe the two have similar compression ignition characteristics, but e35 is not the same as 93 octane e10 as a fuel source.

 

[lucyfek]

Ethanol will increase Octane number but decrease energy amount per gallon of gas so even though ECU will not have to retard timing (etc) to prevent knock you'll not get to the same power levels you expected (can't be extracted from "watered down" gasoline) and your mpgs will suffer (unless you'll end up crawling at more economical speeds than usual). I'm not sure that/if Golf ECU can compensate for increase in ethanol content (beyond what VW designed it for) or if fuel system may get damaged prematurely.
If there was no other reason, I'd avoid E85 just not to support Ethanol lobby.

 

[Whackamac]

I ran an E30 tune on my Focus ST. Have to have a special tune to do it. We found, through research, that on the K03 sized turbos, that there was not much gain past E30 until you upgrade the turbo.

I am very eager for an E30+ performance tune though....

 

[RjRacing]

Ethanol will increase Octane number...

No it doesn't, octane ratings do not change with Ethanol. It's a completely different rating scale, read what I wrote above.

 

[BrianThatCoolGuy]

I was recommended to run 3 gallons of E85 and the rest 93 octane. The car performs MUCH better throughout the whole rev range. PS. This is coming from a guy who barely felt any difference between stock downpipe and CTS' catless downpipe.


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[RjRacing]

I was recommended to run 3 gallons of E85 and the rest 93 octane. The car performs MUCH better throughout the whole rev range. PS. This is coming from a guy who barely felt any difference between stock downpipe and CTS' catless downpipe.


Sent from my iPhone using Tapatalk

Running E85 with gas will help prevent knock if your injectors/pump can supply enough and ECU can adjust. What is your injector duty readings at with the blend?

I'm pretty sure the OEM fuel system cannot handle high percentages of ethanol blend when tuned. I have two tunes for my Evo, a 93oct tune that runs 32PSI at 640AWHP and E85 at 38PSI that makes 720WHP with room for more boost too. To supply enough fuel for E85 I'm running 6AN SS fuel lines, FIC 2150cc injectors and twin 400LPH pumps. The E85 tune runs soo much cooler and smoother throughout the powerband, plus it's much cheaper than race gas.

 

[golfdave]

93 octane?...........no wonder our cars feel so fast our (UK) lowest is 95 octane with 99 being Shell Nitro at the pumps............

Mind you most standard 95 octane over here has a percentage of Bio-ethanol in it as allowed by law............however a few years back a big oil tanker ship didn't wash it's tanks out properly between loads, which resulted in a huge batch being contaminated with too much bio-ethanol............this stuff was for the supermarket fuels.........loads of people who bought the 95 from the supermarkets ended up having to get new lambda sensors, fuels lines, injectors...........big PR disaster..........

 

[DAS_STIG]

93 octane?...........no wonder our cars feel so fast our (UK) lowest is 95 octane with 99 being Shell Nitro at the pumps............

Mind you most standard 95 octane over here has a percentage of Bio-ethanol in it as allowed by law............however a few years back a big oil tanker ship didn't wash it's tanks out properly between loads, which resulted in a huge batch being contaminated with too much bio-ethanol............this stuff was for the supermarket fuels.........loads of people who bought the 95 from the supermarkets ended up having to get new lambda sensors, fuels lines, injectors...........big PR disaster..........

We have a different octane rating system than Europe. Your 95 is our 91 and your 98 is like our 93.

 

[golfdave]

We have a different octane rating system than Europe. Your 95 is our 91 and your 98 is like our 93.

that would explain it then.............

 

[SneakyDeeky]

click link below and then scroll to the bottom... mystery solved

http://www.intercepteft.com/calc.html