I just got done hooking up a zex kit(55 shot) on my single cam hatch. Very impressive how much faster it is. I have heard alot of bad things about zex plugs. I use the same plugs for nitrous that i do on my turbo set up. NGK BKR7E-11. These plugs only cost $1.99 each. I put new plugs in every 2 weeks or so. It makes a difference. I have always loved zex kits. They are pretty safe. I cant belive how much i have spent on my turbo civic to make it run 11's. Then i buy a single cam hatch and it hauls ass with a little nitrous. I'm definately going to stick with the nitrous set up.