Actually, I meant the car's computer. Does the reflash hurt it?

 

Re-flashing the ECU shouldn't hurt anything either.
I have re-flashed/changed custom tunes over a dozen times and haven't experienced any issues.

 

Glad we have some more info.
I've just put a new Sony in the truck as well a Line-X bed liner.
So it sounds money wise as a Spring tune-up with a new 'Bama
...

 

I am happy with my BAMA tunes (run 91 performance almost exclusively) and CIA.
About the same mileage (+/- 1 mpg) and noticeably better performance

The 87 street tune I did not notice a difference in mileage (+/- .3 mpg) or performance- so I don't run it

 

When I first got my CAI I ran it with the 91 Octane Bama tune. But I ended up getting a bit greedy and wanted more out of the tune. It's running a custom tune that my friend helped me do. Been running great off of it, but I am sure it's pushing the limit of what I should do :P

With the Bama I was pushing 412, with custom tuning I went up to 430hp. But just be wary if you have someone do custom tuning lucky my friend deals with just Mustangs so he knows what hes doing

 

Another old guy here with a couple questions.
Two of the things that seem to give you a pretty good improvement in performance is using a Bama tune and changing rearend gears.
For those that have checked before and after quarter mile performance, how much gain did you see with a Bama tune? How about going from 2.73 to 3.31 gears?
Thanks for any responses.