Iv got a stainless centre and back box, and will have a Decat downpipe soon but just want to know what sort of difference if any the headers I bought will make.
If you get equal length headers, you will get more of a performance gain but loose the boxer rumble. With unequal length, you will get some gains, but also retain the boxer rumble. In my opinion, I would not trade the boxer rumble for any amount of hp gain. I pride my car on not sounding like a honda civic, and I plan to keep it that way.
STAINLESS STEEL TURBO/CHARGER DOWN PIPE DOWNPIPE 08-11 SUBARU IMPREZA WRX/STI SS, MXP Stainless Steel Down Pipe 2008-UP Subaru STI MXDPGRB, SUBARU IMPREZA WRX / STI 02-07 MEGAN RACING T-304 STAINLESS STEEL DOWNPIPE 3" ID, STAINLESS SS TURBO DOWNPIPE DOWN PIPE 02-07 SUBARU IMPREZA WRX/STI TURBOCHARGED, 3" BELL MOUTH DOWNPIPE SUBARU IMPREZA WRX/STI STAINLESS STEEL DOWN PIPE EXHAUST , STAINLESS SS DOWNPIPE DOWN PIPE 08-11 SUBARU IMPREZA WRX/STI 2.5L TURBOCHARGED, Stainless Steel Exhaust Downpipe for Subaru 02-07 Impreza WRX STI, STAINLESS STEEL SS 3"TURBO RACING DOWNPIPE DOWN PIPE 02-07 SUBARU WRX/STI EJ GDB, 02-07 SUBARU IMPREZA WRX STI BLACK STAINLESS TURBO EXHAUST DOWNPIPE DOWN PIPE, OBX OBX Stainless Steel Turbo Downpipe 08-11 Subaru WRX STi Sedan & Wagon, OBX OBX Stainless Steel Turbo Downpipe Subaru Legacy GT 2.5L Down pipe, 8 x 3.10" to 3.25" 77mm-85mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 6 x 3.10" to 3.25" 77mm-85mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 4 x 3.10" to 3.25" 77mm-85mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 2 x 3.10" to 3.25" 77mm-85mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 8 x 3.30" to 3.5" 83mm-91mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 6 x 3.30" to 3.5" 83mm-91mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 4 x 3.30" to 3.5" 83mm-91mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, 2002 Subaru Impreza WRX STI EJ20 EJ25 2.5L Direct Bolt On T304 Turbo Downpipe, 2 x 3.30" to 3.5" 83mm-91mm Stainless Steel T-Bolt Clamps Nissan/Ford/Subaru, COBB 3" Stainless Steel HIGH FLOW DOWN-PIPE 02-07 SUBARU IMPREZA WRX / STI, Cobb Tuning Stainless Steel 3" Downpipe Subaru WRX & STI 2008-2012, Tomei Expreme Straight Down Pipe Subaru GDB WRX STI 02 - 07 USDM stainless steel, Subaru Impreza WRX / STI 02-07 - 3" pipe T304 MEGAN Stainless steel Downpipe, Subaru Legacy GT 05+ Manual - 3" pipe T304 MEGAN Racing Stainless steel Downpipe, Subaru Impreza WRX STI 02-07 T304 Stainless Steel Catback Exhaust + Downpipe, STAINLESS STEEL TURBO/CHARGER DOWN PIPE DOWNPIPE 08-11 SUBARU IMPREZA WRX/STI, STAINLESS SS DOWNPIPE DOWN PIPE 08-11 SUBARU IMPREZA WRX/STI TURBO/TURBOCHARGED, STAINLESS STEEL DOWNPIPE SUBARU IMPREZA WRX 02 - 07 3", 3" Stainless Steel Downpipe Exhaust 08-11 Subaru Impreza WRX STI Turbo Catless,