i know that on the stock gsr manifold u hear 2 tones. the 2nd tone kicks in at 5700 and u feel a little lift. with the sk2 manifold, since u dont have the 2nd tone ne more, wat does it do at 5700 with stock p72 ecu? does it gets louder ??

 

Nope. You don't have secondaries anymore, which means there will be no secondaries opening at 5700 rpms.

 

in addition, the VTEC engagement will be too low for a large manifold with a stock P72 ecu, so you will feel a bog at 4500.