Stock you shouldn't be able to beat any 350z, auto or manual. They trap significantly higher then our cars. SO given a decent driver you should lose everytime, no questions asked.

With the TVT250 kit you have installed you should be trapping in the 98mph range, which makes a manual 350z race up to the driver, and an auto race a win.

Congrats on the race, hope all is going well with the new found power.