the new GTS eclipse runs somewhere in the low 15's trapping around 90 MPH.
if it is a 6-speed then he has an extra shift during your 3rd gear, since 3rd gear is the h22 money gear, i predict that with a "good" launch and solid shifting around 7500 rpms you will edge him out by about 1-2 car lengths.
you may also want to remove your 10 amp ECU fuse from under the hood for 10 seconds to reset your ecu. do this a few hours before the race...this is because your OBD2 ecu learns your intake and cat and will detune itself over time to make sure you pass emissions.

the launch is the key
~kris