[Bob Kontak]

Just saying..........I drove my friend's GT3RS for eight 25 minute PCA sessions last fall and I was passed by a Maxima - several times - until the last few sessions. Then I finally smoked it! I made it bleed......... Stock Z3's were eating me alive the whole weekend.

I don't know your experience level but I would pass on the carbs until you drive better than your car can deliver. At that point upgrade to the heavy breather set-up.