Ti
Im waiting for the likes of Veilside, HKS, etc to come out w/ a light-weight Ti exhaust. Ever seen/held a full-lenght Ti exhaust?? Weighs less than 15lbs (sometimes less than 10bls) compared to a stock ones weighing in over 50-80lbs.
The weight shed alone equates to a few extra ponies.
Those typically cost $900-$1200 - not bad considering they have gone thru some extensive R&D and not to mention materials costing much more than steel. Ti exhausts are almost never true-dauls however. Something Im not concerned about tho'