Was at the Mopar Nationals this past weekend, running in Sportsman. Still sorting the car out, but on Friday had two good passes. First was a 13.06 and then a 12.89, after the second pass the car started giving me issues. I noticed after that pass that at idle the car was down about 300 rpms, so i adjusted the idle up some cause at that time i didnt think anything of it. Well the next pass i make the car pulls hard from 1st to 2nd shifting about 5300, and when in second it pulls hard until it gets to 4000 and it starts to breakup. It does this from 4000 till my 5300 shift to third, and does the same thing in third. After that pass i attempted to fix the issue at the track, but had no luck and aborted the pass as soon as it broke up. So i checked the timing today and i had it set at 22 intial at 900 and 37 total, and today it got 10 degrees intial at 900. Thoughts on what caused this?