I think they run low 15's stock maybe 14.9's on a cool, low humidity day. As far as mods don't mess with a chip for these. Jeep already advanced the timing enough on these things that they have to run on premium and the most a chip does is mess with the timing. The only other thing they do for power is play with the air/fuel ratio. Get a FIPK, cat bak, headers, rip a throttle body offf a V10 Ram if it can fit and if its bigger than stock and put it in a 5.9, high flow cat and you'll be running mid 14's and maybe a 14.3 or so on a cool day. These things are very quick for what they are and will show their taillights to alot of 5.0 stangs with just bolt ons, especially off the line and up to around 70.