I took the 6 out to the track this past Friday night so I could datalog and made only two passes. I removed/reversed all mods I did AFTER the TCU tune to see if any gains were made just from TCU mod. I logged the 1st pass and hit rev limiter in 2/3 and 3/4 shift and second pass I forgot to log and hit limiter again but with a loud "pop" sound.......almost like backfiring through intake........and now I am done with this mod. I also ran slower than ever and in great weather managed a best of 12.3@115. I won't race again until I get my TCU returned to stock as it's not worth potentially blowing my engine..........and running slower at the track.