yeah to truely take advantage of the s4's you will have to disconnect that vtc. They are already made to be set in as is and make craploads of power all over the entire power band. My buddy loves them in his s13 redtop with an s15 turbo, even at 8psi it moves but then again i had s4's in my jdm 9.5:1 with that same s15 turbo and at a mere 9psi i was well into the 11's in my 2100 b13, just ask the 12.0 04 cobra and the 11.9 zo6, hahahaha