air intakes

[nolove670]

any opinions on the Weltmeister Airbox cover. the company claims 10 hp increase just by changing the air box cover to this open type cover. can this be true, and is it worth it $200. has anyone used it?

[dorschman]

I saw some listed as "performance" that basically had most of the box cover removed with a little lip to help with water entrance. I dremmeled mine to the same effect. Not sure if this is what you refer to. You can search and see some good pictures by some other guys (Will Ferch?).
My understanding is opening up the air box cover makes nice sound but no hp increase. Hope this helps.

[CharlesJones]

I've heard that no air box cover would increase power unless your engine is substancially tuned elsewhere, let alone anything as substancial as 10 bhp. Apparently the standard air box flows plenty of air for a standard engine, and changing it makes no difference apart from maybe creating a bit more induction noise.

I've also heard that the standard air box cover takes air from a cooler part of the engine bay than some of the non-standard ones, and so is beneficial since cooler air is denser. I don't know how true that is though - I'm not sure how much air temperature variation there is in the engine bay, but presumably there must be some reason why Porsche designed the trumpet of the air box to be positioned underneath the engine grill.