Tuning question???

[Stephen06GT]

This came up in a discussion earlier this evening and I did not know the answer. When your ride is being tuned for use with various octane fuels, does the fuel have to change For each tune or are the lower octane tunes based off the highest octane rating? Or???

[ZR]

If I'm interpreting your question correctly, tuner is loaded with both 91 plus 94 tune, how was it done? First tune would have been the 94 version, yes it required 94 in the tank. If you said to your tuner, want the option to run 91, he'd take out the amount of timing he'd think would make it safe to do so and tweak a second / 91 tune at the same dyno session.

What many don't realize, if your boosted (or even N/A, unless running big compression) there is absolutely no issue if you had to dump a tank or part tank of 87 in there so long as you don't throttle it into boost. Under no boost, engine has no idea if it has a supercharger up top or not. I'm sure at least some of the boosted crowd don't attend longer / more remote cruises because of spotty 94 availability. Another option, dump in 91 and a can of Octane boost.

[allicedout]

I think its important to know what each tune is being used for. If the car is always on 94 and you want the 91 for when you can't find any 94 then I think a reputable tuner would be able to dial that in without 91 octane in the car. But if a 94 octane tune is going to be a track tune and 91 octane for daily use I'd think it would make more sense to have both tunes done using the correct fuel.

[ZR]

Under those circumstances / if funds will allow, absolutely. Although, many tuners feel they can confidently / accurately dial in a safe 91 tune without a second session + 91 in the tank.
In my own, track tune has less timing etc but both it and street tune are on 94.

[tulowd]

The specific ethanol content is also critical when tuning to the limit, especially under boost, as each time you fill the tank it can have different percentage mix. Lots of racers do a specific gravity check before each dyno run and at the track to ensure they understand what is in the tank. Only 91 Shell would be consistent across the board, since it is ethanol free.

[Stephen06GT]

Thanks for the replies. I thought the answer was what ZR and Hemant mentioned, but I wasn't certain so that is why I asked the question. As far as the specific gravity testing, Ol Paint is not tuned to the limit so the testing ain't gonna happen. :D

[allicedout]

When's the "coming out" party?? Can't wait to see it person!

[Monera3v]

Hurry up and bring her out :P
It's sister Monera want's to play XD

[Stephen06GT]

Insurance goes back on this Saturday.

[Monera3v]

Insurance goes back on this Saturday.

Sweet, I just called my broker today, and said Well Look it hur, its nice and purty outside! Put that stang back on full coverage!

LoL, (yes that was my exact words)

[MUSTANGWOP]

Insurance goes back on this Saturday.

Then go shopping for 2 new tires on Sunday ;)

[Monera3v]

Then go shopping for 2 new tires on Sunday ;)

Def going to need it, my brand new tires only lasted me 1 summer with all this boosting XD

[Uncle Buck]

Mine was tuned with 91 Shell in the tank. I run 91 all the time and try to get Shell more often then not.

Does anyone know the real world RWHP difference in their ride between a 91 tune and a 94 tune?

[ZR]

To me, conservative tune and let the h/p numbers fall where they fall then dump in the highest octane at the pump and give it hell. This whole angle 94 octane isn't real because it's got alcohol mixed in just doesn't fly with me.
JMO

[allicedout]

To me, conservative tune and let the h/p numbers fall where they fall then dump in the highest octane at the pump and give it hell. This whole angle 94 octane isn't real because it's got alcohol mixed in just doesn't fly with me.
JMO

I couldn't agree more. My take on the 94 debate is this - your car was tuned to what is in the gas tank, not what the pump says in in your tank.