Blitz Supercharger= $5000+INSTALL= Mucho Dinero
Adds only about 35 hp.
Does fit under Celica Hood
XS Engineering Turbo=$4500+INSTAll= Mucho Dinero
Adds nearly 100hp with Exhaust, Intake
filter, and cams.
Does fit under celica Hood
50-100 Shot nos= $500 for kit+ INSTALL + any mods you want (like Forged pistons, etc.) to make your motor more durible= Mucho dinero
Does fit in Celica (Bottle in back)TRD
parts DO NOT void the warranty if installed by Toyota Dealership (Mucho Dinero, subject to thier prices). As for a Super Charger, though, I wouldn't be so sure that would be covered. If it is really coming out, though, I'll get the damn thing only if it's less than $3500 and adds more than 50hp.
Otherwise, just get NOS and beef up the hard stuff in your motor. More power for the money.