It Depends on what vtec controller you have... i did a gsr swap in my 92 hatch and bought a spoon sports vtec controller.... what it does is allow you to set your vtec at so why let it start at 5,000 rpms do it at 3 or 4,000 rpms... there is an apexi i think thats how to spell it that does the vtec timing and air/fuel ratios..
Hope That Helped....