Ok so my mods are: helix dp, helix testpipe, hks carbon/ti catback(possibly changing it though), hks drop in filter, and 255 pump.

I am going to be getting the cobb AP and having a race gas map made, but was wondering what gas I should use? Will leaded fuel do anything for me?

 

i think the leaded fuel will just foul up your plugs... eventually...

 

I wouldnt be running it very often. Im just thinking that I wouldnt gain anything over 104 unleaded with my mods

 

Leaded will kill your O2 sensor. I don't think you'll need leaded until you're running a pretty large turbo and a lot (~30+ psi) of boost. Or somewhere along those lines.