im not going to call bs, i am trying to be logical here.
his wrx ran a 14.1 and now has a turbo back exhaust which could easily net him a 13.9.
figure a well driven 6speed GTO will run 13.8 (this is an average of 3 different times)
with how much it weighs and if it was an automatic its probably only good for 14.2-14.4
(figure a 6speed z28 ran on average about 13.5 and the auto ran a 14.0) so add half a second to the GTO auto time as compared to the 6speeds time
after all this, you could assume the wrx is running a 13.9 and the GTO is running a 14.3
although the GTO has better top and such, you calculate driver error (he probably punched it in the gto where as the wrx downshifted first manually) and I think all this could come to his 1 car lead on the GTO.