Yeah it was a nitrous backfire. I was making a "test run" and somehow the damn ignition wire came completely undone when I went from first to second. Result was a LOUD boom!!! Went to the track friday night and did fine. Ran 7.9's at 86mph. I'm well aware that it ran slower than usual due to the timing being retarded more than usual. I just have to decide whether or not to mess with the tune, and keep running the 100 shot, or try the 150 shot again and iron that out lol.