i posted this on another thread a couple days ago. if u get long tubes u will get a decent gain. same with short ram until it warms up in you engine bay
long tube intake dyno
STILLEN Longtube G3 Intakes. Review, Dyno and Impressions.
~20whp gain
short ram dyno
K&N Intakes Installed w/Dyno
~14whp gain
33% difference of hp gained in short ram vs long tube
i'm sure there are many variables that play into this, but these were just some quick examples i found