i ran my car on 17s with 10lbs of boost on the greddy kit and got a 13.3 @108 with a ****ty 60ft time, the greddy kit is def worth it but it sux cause it comes with a 2 1/4 inch down pipe and you have to do a lot of custom work for the 3". Im gonna run 14lbs of boost on the next run with slicks and im looking for a 12.2 so the greddy kit is a good choice, but im by no means just a bolted on kit, youll still need a lot of nescesary extra things