Guys I have had about 6 run in's with Z's, has not pretty for them and most of the races I had 2-3 passengers. From a roll they have more of a chance but in my experience I pull away very easily putting alot of car lengths. One could argue bad Z driver, at least that's what they say? From a dead stop once I raced one with one passenger, I had 2 passengers (me= 240lbs, cousin=185lbs, girl = 120lbs) ...so we both take off from a dig I never launch just feather in about 3500 rpm. He stayed with me half way through 1st then I hit 2nd put about 4 car lengths and continued making distance. He might have given up who knows?
As far as the Z guys they are convinced the Z is quicker than the Sti, I would leave this alone no need to start a war. Here are 2 forums you can find Kill stories on Suby's!
http://www.my350z.com and http://www.350zmotoring.com
2004 Sti bosal dp with Ecutek 280awhp and 293 lbs @wheels