Originally Posted by Taylorbrt4
what kind of tune am I able to do without having any upgrades to my 05 stock gt? am I able to increase power in any way
You'll absolutely notice improved performance with a custom tune on your bone stock '05 GT. S197 Mustangs especially perform well with a custom tune because they tend to have a lot of throttle lag from the factory. This is drastically improved with a custom tune, among other things. You'll experience an increase of power throughout the RPM range and possibly a slight increase in MPG if driven correctly.
A custom tune
is great without a doubt, but you'll pick up significantly more HP & TQ if it's paired with a CAI. The factory 05-09 GT intakes are fairly restrictive and truly benefit from an aftermarket CAI, like Airaid or JLT
You can always feel free to contact me via PM if you have more questions or concerns down the road!