I've tried 3 downpipe/back exhausts last friday on a Dyno .... here are the results
Mod's :
7 psi boost
CAI Injen
FMIC Turbotech
Stock line
160.1Whp
156.7 Tq
Exhaust line made by muffler shop downpipe/back (suposed to be hi-flow , with cat , resonator , dynomax muffler)
162 Whp
158.5 Tq
Exhaust line made by Turbotech downpipe/back (2.5 inch 304SS , mandrel bent , with hi-flow cat , resonator , muffler)
173.9 Whp
164.4 Tq
All this @ 7 psi boost
(Dynapack Dyno)
Downpipe coming soon with Dyno results
Hope this helps !