Quote: So, but you also need some back-pressure, otherwize you push the torque curve way up & there goes your 60ft., so run at least 18" extentions or install cutouts (dumps as i call them)
cant this myth about backpreasure being good for a 4stroke engine just die? you are right about adding lenght to the collectors to make a correct collector length but thats not for backpreasure that is to be able to take advantage of the pulses in the collectors to get all 4 pulses from the same bank tuned and work togheter, thats as good as i can explain it since my english is fairly crappy..
i dont think the threadstarter will gain much from open headers, maybe a tenth or so from the lost weight unless the exhaust has some problems (reduction in diameter in the bends or some other restriction) built into it in the first place
