93.5 octane

[281Ponies]

Sorry if this has been covered already… just ordered the xcal2 from Brenspeed with the 3 standard octane tunes. I know not to run the 93 tune on 89 octane but what are your thoughts about the running the 93 tune on 93.5 octane? It’s available here and was just wondering if you would try it. Think there would be that much difference between the tune and octane to matter or do you think it could still have adverse effects.

I will most likely run the 89 tune and octane for daily use but was wondering about this on track nights.

 

[DarkFireGT]

93.5 is fine. You can run higher octane (as long as it's NOT leaded) without any ill effects. It's when you run lower than your tune that you'll have a problem.

Doug recommends to drive down to 0 gallons, fill up with 93 (or 93.5 in your case), run that out, fill up with 93 again, then install your tune.

 

[ranger04]

It's the lower octane fuels that will cause detenation with these tunes, your ok.

 

[281Ponies]

Thanks

 

[bigcat]

93.5 is fine. You can run higher octane (as long as it's leaded) without any ill effects. It's when you run lower than your tune that you'll have a problem.

Doug recommends to drive down to 0 gallons, fill up with 93 (or 93.5 in your case), run that out, fill up with 93 again, then install your tune.

you mean unleaded?

 

[DarkFireGT]

Lol good catch, Bigcat. I meant as long as it's NOT LEADED

I hate typing at work. My head is not where it should be.

 

[bigcat]

i edited the first post you made, and included the NOT.

 

[281Ponies]

I didn’t notice it either... good eye cat.

I’ve been running 89 octane so when the tuner arrives I’m loading that tune.
Is running a tank of 93 octane before uploading that tune necessary? What is it the computer... does it take that long to adapt... to get the benefits of the tune? Must be an initial process and then just run the tank low enough for a different octane and flash it. Or is this something I need to do every time when stepping up in octane tunes...?

 

[Hoboattacker]

I'm assuming the reason for running 93 through the tank twice is to make sure that you get all of the 87 or 89 out of the tank and out of all of the lines. Less chance for problems if you only have "pure" 93 octane in it instead of a mix of different octanes.

 

[kooldawg6]

I ran my tank of 87 down to where it said 0 miles to empty then filled it up with 93, loaded the 93 tune right in the parking lot of the station and it did fine. I was hard on the go pedal as soon as I pulled out of the parking lot If it did infact take the second tank of 93 running through to get the full tune potential... I didn't notice it.

 

[DarkFireGT]

I didn’t notice it either... good eye cat.

I’ve been running 89 octane so when the tuner arrives I’m loading that tune.
Is running a tank of 93 octane before uploading that tune necessary? What is it the computer... does it take that long to adapt... to get the benefits of the tune? Must be an initial process and then just run the tank low enough for a different octane and flash it. Or is this something I need to do every time when stepping up in octane tunes...?

It's to ensure all of the lower octane gas is out of the car. I drove down to 0 and put in 93 and loaded my tune, but I'm a risk taker. The safe method, and the method that Brent and Doug both approve of, is the aforementioned method of filling up twice before the new tune. The only advice I can give you is fill up twice, or your run the risk of detonation.

 

[281Ponies]

I can understand how you would want to avoid mixed octane… get the 87 or 89 octane out as best you can by running the tank as low as you can before upping the octane and tune. So, if I understand when you want to run a lower octane after a higher octane simply run the tank low, fill up, flash the computer and drive away. It’s only when stepping up in higher octane it is recommended to run two tanks before the flash. Hate to beat this to death but I may switch octane fuel regularly and want to avoid any possible detonation.

 

[ranger04]

You could also fill up with 93 and add some octane booster to help bump up any remaining 87. I'm just not sure of which of these off the shelf octane boosters can be trusted to deliver. I like outlaw, just don't know it a couple of bottles would do the trick or not. I guess you could throw in some aviation fuel or race gas from the sunoco to boost the octane, or just run the 2 tanks of 93.

 

[Hoboattacker]

You could also fill up with 93 and add some octane booster to help bump up any remaining 87. I'm just not sure of which of these off the shelf octane boosters can be trusted to deliver. I like outlaw, just don't know it a couple of bottles would do the trick or not. I guess you could throw in some aviation fuel or race gas from the sunoco to boost the octane, or just run the 2 tanks of 93.

Octane booster fouls the plugs in our cars. Well, it puts this weird orange color on them and I'm gonna assume that isn't good for them.

 

[Hoboattacker]

I can understand how you would want to avoid mixed octane… get the 87 or 89 octane out as best you can by running the tank as low as you can before upping the octane and tune. So, if I understand when you want to run a lower octane after a higher octane simply run the tank low, fill up, flash the computer and drive away. It’s only when stepping up in higher octane it is recommended to run two tanks before the flash. Hate to beat this to death but I may switch octane fuel regularly and want to avoid any possible detonation.

I do it all the time, there isn't much to worry about if you are just driving on the street. I've only noticed slight pinging when running 89 on a 91 tune on the street if I get on it through first and second and part of third. But just daily driving you wont notice a difference at all. A/F ratio is only changed when you are at WOT. Other than that it's a stable ratio (forgot the ratio though).

 

[DarkFireGT]

I can understand how you would want to avoid mixed octane… get the 87 or 89 octane out as best you can by running the tank as low as you can before upping the octane and tune. So, if I understand when you want to run a lower octane after a higher octane simply run the tank low, fill up, flash the computer and drive away. It’s only when stepping up in higher octane it is recommended to run two tanks before the flash. Hate to beat this to death but I may switch octane fuel regularly and want to avoid any possible detonation.

Yes, you've got it

You could also fill up with 93 and add some octane booster to help bump up any remaining 87. I'm just not sure of which of these off the shelf octane boosters can be trusted to deliver. I like outlaw, just don't know it a couple of bottles would do the trick or not. I guess you could throw in some aviation fuel or race gas from the sunoco to boost the octane, or just run the 2 tanks of 93.

No octane booster. They foul the plugs and don't help in getting you where you need to be. A few gallons of unleaded race gas, or torco fuel additive would be better, but still. Just wait a few more days until you've got all the lower octane fuel out and be safe. You have a brand new car. No reason feeing it a bunch of garbage.

 

[281Ponies]

I appreciate all the helpful info guys.

I ordered Monday so it’ll be next week before it arrives... just can’t decide if I want to start with the 93 octane tune first and find out what the difference is that weekend at the track over a stock tune or start with 89 and work up to 93... either way can’t wait to get flashed.

 

[DarkFireGT]

Well, change to 93 your next fuel up so you can start the process