Good afternoon, I'm looking to get the best tune for 2012 Dodge Challenger SXT 3.6L, I see that it has 87 tune and 93 tune, Throttle Boost and a list of other adjustments. I'm looking to increase to the best performance this device can offer. My vehicle has the 2.65 rear end can this device help or change the gears? please forgive me but I'm sure that there are plenty of people on this forum that can offer the best advise. New to Diablo and I want to make sure I'm doing this right.
A tuner isn't capable of changing out a transmission's gearing ratios--it's not an electronic ratio in the computer, but a physical ratio based on the size, teething, and other bits in the actual transmission.
As for changing out the gearing itself...well, it's theoretically doable (I've wanted to do it myself), but the process would be in the thousands of dollars range (it's far more involved than rear end swaps in other vehicles).
I have a Charger 3.6L, and I bought my In-Tune and custom tuning from Hemifever. He's great, and will walk you through the whole process. If you haven't already bought your Diablo, getting it with his tunes at the same time is a savings over getting the tuner and then getting the custom tunes.
If you already have the Diablo, then he'll still sell you the custom tunes at a pretty good price (I'm sure other tuners will as well, but he's the one I'm personally familiar with).
If you have an intake and a good 93 octane tune, you definitely see some significant improvements under full throttle (for me, the biggest improvements were in 2nd and 3rd gears, after the beast was already rolling along).
I would recommend against personally doing too much changing to the tunes that come from Diablo until you know what you're doing--you are talking about your engine, after all.