questions about an hx

[geisi13]

ive read somewhre here in af that the hx motor (y5) runs on just half the valvs until it hits 2500 rpms, is this true? if it is can i just simply swap the ex ecu in to have it run like normal or do i need to swap the whole head, i have vtec well actually vtec-e and wasnt sure if i could just make it like the ex with the ecu. if i have to swap the head are there any other options besides the y8 head like maybe the z6 or wold the y8 hed be the best one anyways. i think if i get rid of this half the valves shit i might be able to get a little better launch cause i have the shittiest launch ever right now hah i wouldnt even call it a luanch but from a rolling start its not bad at all.