Have a look at this (Dyno plots available):
http://bob123e.tripod.com/thegreatheadertest/

Baseline = 176 hp/119 tq

JDM Jun HP/TQ 186/ 138
JDM Spoon HP/TQ 187/ 138
JDM ITR 4-1 HP/TQ 185/ 137
Mugan mod. hytech HP/TQ 187/ 136
DC JDM 4-1 HP/TQ 187/ 137
Comptech 4-2-1 HP/TQ 187/ 137
JDM Toda HP/TQ 190/ 137
JDM Mugen HP/TQ 186/ 135
SMSP header HP/TQ 190/ 136
Type 1 HP/TQ 186/ 137
2.5" exhaust/test pipe HP/TQ 180/ 131

Found it first on jdmyard