Whats the difference between the gt28r and the gt28rs? And what housing is recommened for the gt28r? Ash what mods did the car have to put those numbers down and psi is running? I found a pair of gt28r new for $1500 is this a good deal? Iv yet to see someone recommened the z1 gt525r and even talk about that setup wonder why. It's just funny everyone seems to be talkinga bout the gt28r for the last week.