I didn't loose any percievable torque with my brospeed (its a 4-2-1). I also had the original pacesetter which was 4-1 and still didn't loose any percievable torque (it used the factory downpipe and I have a 5sp though). Comparisons have shown that although a 4-1 header is a top end/narrow range design and a 4-2-1 is a midrange/broad range design it really depends on much more than just that. A 4-1 design with a better collector and better suited piping size may have better low end torque and top end power than a 4-2-1 header and vise versa. I truly believe the collector design is much more important than the piping configuration because a bad collector will restrict flow more than anything. (peace out. Drunk on a monday evening and no one to screw).