Updating a tune

[Robot_trainer]

Refresh my memory on the correct procedure for updating an existing tune (for example changing from a 91 octane tune to a 93 octane tune). Do you restore the OEM tune first, then the tune or can you just write the 93 tune over the 91 tune?

Your opinions matter!

 

[Chancey]

Refresh my memory on the correct procedure for updating an existing tune (for example changing from a 91 octane tune to a 93 octane tune). Do you restore the OEM tune first, then the tune or can you just write the 93 tune over the 91 tune?

Your opinions matter!

I had to go back to OEM, then swith 91 to 93 and vice versa on my 2017 Mustang GT (hand held SCT w/Lund tune). I havent messed with the GT500 just yet. Wish I could help ya man. I will have to find out myself soon.

 

[RBB]

I always just overwrite the previous tune without returning to stock first. Never had an issue doing it that way.

That said, I believe the “correct” procedure is to return to stock first. I’m not sure why that would matter as long as you have saved a copy of your stock tune, therefore I don’t do it.

 

[stanger1]

I have always just uploaded the new tune without going back to stock.
I believe that the only time you should go back to stock is if you are updating the device on SCT's website.

 

[Robot_trainer]

I have always just uploaded the new tune without going back to stock.
I believe that the only time you should go back to stock is if you are updating the device on SCT's website.

I believe you are correct! Thanks for the opinions. Now I have the dilemma of staying with the 91 octane tune so i can use the non-ethanol fuel, or gain a little and go to the 93 octane tune and run the E10 93-94 octane tune. I'm leaning toward the 91. I just street drive it so I doubt I'd see the gain.

 

[stanger1]

I think most tuners, and Ford, will allow the timing to advance if the Knock sensors are not seeing any knock, so if tuned for 91 octane and you have some 93, if the computer is happy, it will advance the timing, taking advantage of the increased octane rating.
From my research, I think you are better off staying away from the the No Ethanol fuels and running the 10% or standard fuels, or tune and upgrade for E85.
I was always told the no ethanol fuels were made for the farm, boating, etc, the bottom of the barrel type fuel.
Not an expert by any means, just research and Q and A.

 

[96gt02]

Yeah just reflash over the current tune, no need to go back to stock unless there is an issue during the tuning process. You can even change between different companies tunes without going back to stock, doesnt matter unless they change the ecm strategy like AED does for example, in which you would have to go back to stock to then flash a different companies tune.

 

[Robot_trainer]

I think most tuners, and Ford, will allow the timing to advance if the Knock sensors are not seeing any knock, so if tuned for 91 octane and you have some 93, if the computer is happy, it will advance the timing, taking advantage of the increased octane rating.
From my research, I think you are better off staying away from the the No Ethanol fuels and running the 10% or standard fuels, or tune and upgrade for E85.
I was always told the no ethanol fuels were made for the farm, boating, etc, the bottom of the barrel type fuel.
Not an expert by any means, just research and Q and A.

You are the second one that has said that, but for different reasons. Others feel the the water absorption fears are over rated and that it takes a long long time for the fuel to phase separate while sitting in a relatively air tight fuel tank. They feel the advantages of the extra octane from the Ethanol outweigh the disadvantages. According to the owners manual we are good up to e15

 

[Norton]

My tuning experience is limited, but mirrors what others have said about how to update/flash an ECU.

I'm also no fuels expert, but I respectfully disagree that ethanol-blended fuel is better than unblended fuel. Newer cars are compatible with ethanol-blended fuels but, unless they're tuned specifically for it, unblended fuel seems like a better option for several reasons...
- Ethanol holds less energy than gasoline, so performance and mileage both suffer from its use
- Ethanol offers high octane, but that means little once its blended; 91 octane is 91 octane
- Ethanol is hygroscopic, so it absorbs water from the atmosphere
- Ethanol is subject to phase separation, which can be problematic for those who store our cars for extended periods
- Ethanol is corrosive
- Ethanol can damage (older vehicles') rubber seals and engines

FWIW, the Sunoco fuel reps at SEMA recommended using an unblended fuel (that offers twice the shelf life of blended options) when storing vehicles.

 

[Robot_trainer]

The only reason I was considering going blended was that they offer a 93 and 94 octane E10 so I could run the 93 octane tune. Most of the 91 around here is non blended and I'm thinking for the use of the car and the amount of gain, it might not be worth switching. 93 and 94 are harder to come by.

 

[Norton]

The only reason I was considering going blended was that they offer a 93 and 94 octane E10 so I could run the 93 octane tune. Most of the 91 around here is non blended and I'm thinking for the use of the car and the amount of gain, it might not be worth switching. 93 and 94 are harder to come by.

That makes sense. Unless I specifically get race gas, the highest octane available here (blended or not) is 91.

I'm not sure how much of a (butt dyno) difference there really is between 91 and 93. Given that our cars are compatible with blended fuels, you could consider running 93 through the "car season" and, then, store it with unblended 91.

 

[Robot_trainer]

That makes sense. Unless I specifically get race gas, the highest octane available here (blended or not) is 91.

I'm not sure how much of a (butt dyno) difference there really is between 91 and 93. Given that our cars are compatible with blended fuels, you could consider running 93 through the "car season" and, then, store it with unblended 91.

I was running the 93 tune for a couple of years with 91 non ethanol and Boostane (like a quarter of a can per fill up and it was fine). I want to get off the Boostane teat as its one more thing to carry around and mess with. I could do the ethanol in the summer and non-ethanol for storage.

 

[Cman01]

The only reason I was considering going blended was that they offer a 93 and 94 octane E10 so I could run the 93 octane tune. Most of the 91 around here is non blended and I'm thinking for the use of the car and the amount of gain, it might not be worth switching. 93 and 94 are harder to come by.

I don't see how 94 octane fuel is hard to come by where we live. PetroCan (formerly Sunoco) carries 94 octane fuel and has up to 10% ethanol. However, only certain PetroCan stations carry it so maybe that's what you are saying AFA that fuel is harder to find.

There are now some Mobil stations opening up in the GTA (Greater Toronto Area, which covers where the OP lives), they carry 93 octane again with 10% ethanol.

Shell up here in Canada carries 91 octane (their highest octane fuel at the pumps) which has no ethanol, but Shell stations in the US carry 93 octane which has up to 10% ethanol.

Tony

 

[Bearbo]

93 no octane here which is all I run. Add Boostane and she roars like a Lion. Only way to get any higher octane is in 5 gallon pail or 55 gallon drum which I have considered.

 

[Robot_trainer]

I don't see how 94 octane fuel is hard to come by where we live. PetroCan (formerly Sunoco) carries 94 octane fuel and has up to 10% ethanol. However, only certain PetroCan stations carry it so maybe that's what you are saying AFA that fuel is harder to find.

There are now some Mobil stations opening up in the GTA (Greater Toronto Area, which covers where the OP lives), they carry 93 octane again with 10% ethanol.

Shell up here in Canada carries 91 octane (their highest octane fuel at the pumps) which has no ethanol, but Shell stations in the US carry 93 octane which has up to 10% ethanol.

Tony

Yes, that is what I meant. We have a few Petro stations that have it, but you have to look for them. The esso stations are mostly GTA. There is only 2 that carry it in my area.