you can do 12's on a stock car. I did 12.7@111 with a stock 2000z28 m6 with street tires. tire pressure was around 22psi temp was around 74 degrees. I launch around 2200 droping the clutch sometimes it spins some times it dont just depends if I got all the water off during the smoke box.the only mods that are done are free ram air and bottom of air box cut out. so it can be done. just takes practice. good luck. randy