This isn't the correct way to link internally to a thread on this site (but it's the best I can do)
Approximate fuel tank capacity and range of 996, 998, 999 and 1098? but 998gsb on this thread, told me he is using a bmc air filter - he's also got a PCIII - the combination of the two he reckons is giving him an extra 6 RWBHP on his 998. I looked up the filter - about £160 'ish which doesn't sound cheep to me - but I'm thinking of letting my 998 breath easier (she's got a full system 60mm Termi) then investing in a PCIII and getting some proper mapping by Dynojet to make it all sweet...