hie all zthians,
from my experience, 4-2-1 is gud 4 low (1-3.5k rpm) end rpm range n 4-1 for mid n high end rpm range.
just 2 ask sumthing 4 u guys, for auto cars, it is not advisable 2 use straight pipe exhaust right? can sumbody explain y? n also from sum ppl's POV, twisted center...