Tom03GT

I have an 03 GT with a magnaflow magnapack exhaust on it and bought the car used from a dealer. My dad has an 08 GT/CS mustang and we were on the highway the other day and I pulled up next to him to have a little fun. We were both in 3rd gear at about 4000 rpms and floored the cars and suprisingly his mustang could not pass mine. He has a ford racing exhaust on his, so the exhaust on mine could not have made that much of a difference. The only thing I could think of is if my mustang has been previously programmed by one of those hand held chips because with our cars bearing the same weight, and his car having 40 more horsepower, I just dont understand why he would not be able to blow by me. So my question is this: Is there any way to tell if the car has been reprogrammed by one of those hand held chips? It doesnt make sense to me that he wouldnt be able to pass me.

ct_white_stang

You could have gears and I think the 08 is heavier.