Sounds like u did what i did,when u get a ff tune from lune the first one is a 93tune if u never had a tune from them.After u send in logs he will then send u a flex tune,i found out the hard way too after filling up with e85 and noticing no changes in af.I had to drive all the back from the track like that but just took it easy.Guys keep this in mind when getting a flex tune.
Even with the FF tune the minimum you should run is still 91. So does you no good there. And if you get bad 91/93 it does the same thing the 93 tune does. It senses knock and pulls timing. So no difference there either. Only benefit is for the guys that want to run E85 can run different mixes without causing any damage, or if no e85 can be found, you can run 91/93 without switching tunes or causing damage. And if you prefer can also take advantage of race gas or octane boosters and get a little more timing over a 93 only tune. But the FF tune is no safer than the 93 tune when getting bad gas.
I was told by Lund Racing that the stock injectors are just fine with the flex fuel tune. Now if you upgrade the intake manifold, add boost, or nitrous then yes you will need to install bigger injectors. I believe 47's were recommended for the GT350 intake manifold.
No lu47 needed . Who told you this ? I'm keeping track
I've been hearing that a lot . 1000 bucks to run 113
