It is hard to tell from outside the car, but when I was at the track this weekend the last two runs when I went into 4th gear the engine cutout for a millisecond and cut back in. both with and without the nitrous. Has anyone ever had this symptom before? I know everyone will say opti just like I am, but please chime in if this is familiar to you.

 

could be a short, i dunno why the opti would only shut down only when going into 4th