and yes like said before a longer tuned length will slow the return resonance and work better with a short duration setup.. so a low-mid setup.. by shortening that tuned length the pipe returns sooner that works well with a longer duration exhaust port.. gettign the pipe to return at the right time in comparison with the ex port is the key.. if you played with the adjustment on a dyno you'd be able to actually tune the pipe to teh engine. there are ALOT of adjustable LRD pipe on banshees runngin around..