Church Creek TT practice: negative split, how fast can I go, who is faster, X-1 launch from a B2

Church Creek is tomorrow and I am a good mix of anxious and excited.  It has been several years since I have done well there.  I have been using a Hed3 front clincher, zipp disc rear tubular, and an aero helmet (Rudy, now an Advantage2).  I have been using shoe covers.  I have had the same TT frame, fork, bars since 2006.  So there is no equipment for me to upgrade, really (2011 Felt DA, what?!)
I went out yesterday after a rest day to practice some TT efforts.  I did an 8 mile negative split interval (laps 7 and 8 at the bottom), and a 3 mile field test (lap 10). I practice because there has a been slowing trend in the last 3 years.
2008- 58:32 25.4 mph
2007 56:53, 26.2 mph (?)
2006
2005 57:55 25.7mph (won the 4s)
I have been looking at the start roster trying to figure all the people who will beat me, its hard to predict.
I want to have a negative split (second half faster than first half), I hope it feels like the video below.
I did go back to an old TT trick:  the high pressure, 700x20 front tire clincher.  For me, it makes a ton of difference- it says Supersonic on it...  that has to be good, right?



NAsa movie with an X-1 launch from a B-2.