Ok i finnaly had a chance to dyno the difference the exhaust system made. First off my base run on a dynojet uncorrected was 187whp and 139wtq, this translates to 183whp and 136wtq SAE corrrected, the power difference is SAE corrected #'s so noone can talk smack. the power jumped to 188whp and 144wtq SAE corrected!! with a gain of over 10lbs of tq at 6000rpms!!
. So basically i gained about 5whp and 8wtq and those are the low SAE corrected #'s. this is on a bone stock si with no other mods.
BTW for fun i did a run with the bottom of the airbox disconected form the resonator and i lossed about 10whp and 10wtq , so dont mess with your stock intake or the turbulence with screw with your MAFS readings resulting in a loss of power.