I installed the race quad on my 2003 235hp CA auto truck about a week ago. I was running the EZ and installation of quad was fairly easy. On the 60hp setting truck ran about the same as EZ on level 3 or 4. At the 100hp setting truck was noticeably faster. I liked it was I was feeling from the box. Now when I put in on the 140hp setting I didn't really feel any change from the 100hp setting. I am going to dyno my truck on the 16th of this month and I will see what is going on. The box does run real smooth. I hope they make a HOT RACE BOX in the near future that gives us more ponies. I took off the EZ elbow because I throw a code (0148) on the 140hp setting. I put stock elbow on and have not seen code since. Overall I am very pleased with the box and price is fair.