I HAVE A 91 WITH 80K MILES. I HAD THE FOLLOWING MODS. HEADERS, INTAKE, EXHAUST AND DALI CHIP. I DYNOED AT 258RWHP, IN THE HOT,AND VERY HUMID SOUTH FLA. CLIMATE. I'M SURE IF I HAD IT DYNOED UP NORTH IN A NON HUMID CLIMATE IN THE SUMMER, IT WOULD HAVE DONE BETTER. I CAN SAY THAT I AM TOTALL CONVINCED THAT MY CAR IS FASTER THAN A STOCK 97+, AND NOW WITH THE ADDITION OF A 6SPD,AND 4.55'S, I KNOW I'M DEFINATELY FASTER. TITANIUMVTEC HAS A POINT, THE 6SPD IN THE 97+ IS WHAT MAKES THEM SUB 5 SEC'S 0-60, WITH OFCOURSE ABOUT 10-15 RWHP MORE.