I added the PD160 intake and a green filter to my
Ibiza PD130 ages ago, and have the following comments to make:
1) It won't really increase power. But it makes the engine slightly more responsive, and quite a few people (myself) included found it made the engine smoother to drive on light throttle / around town (a bit like people have found when doing the EGR mod, see other thread).
2) If the new intake rubs against the small diameter water pipe. You don't want to leave it like this, these engine move around a huge amount, and the last thing you want is a pipe rubbing through a few months after you're forgotten about it. On mine, I slackened the clips on the small water pipe, and rotated the pipe slightly to a position where it wasn't touching the intake. Then released the clips. If I remember correctly (don't have the car any more) the clips are the type with sprung tabs that need squeezing together with pliers or molegrips to release.