Hi y'all
I'm thinking of buying a new filter unit for my motor (96' 328i), one of those panel (not a pod unit) jobbies in a carbon fibre housing. The guy in the shop reckons they're good for another few bhp, while a guy in the local garage says they're crap and fitting one will have an adverse effect on performance.
I see by some of the posts here that many of you recommend this upgrade, but I'm wondering whether any of you have any hard facts to back up the claim of increased performance, such as dyno test results etc.
Many thanks.