forget the plugs (stick with iridiums), wtf is a power boost valve?
if you want real gains, start with Intake
and exhaust and header. then look into engine management such as power fc, get some supsension/tire upgrades/ light weight rims and you'll be good to go
I had to look this one up. Power boost valve replaces the stock valves in your engine. Mostly, it gives the car better acceleration by increasing the fuel pressure. I guess its the new craze in Europe because every site that popped up was from the UK. Haven't heard too much about it in the United States.
I second Lucky_317. Start with a CAI
or if not at least
get a Performance Air Filter
. Exhuast and some lightweight headers. Thing to remember is weight reduction
. Aftermarkets are almost always less weight. The miracles of Carbon Fiber!
BTW, only iridiums will work in Celicas. Check your manual if you don't believe me.