If you are going induction kit then preferably get one with a maf housing and velocity stack, like the hks rsk. It makes quite a loud noise. It's quite straightforward to fit but you will need to replace a coolant hose. This is included with the kit when bought new and it's not as daunting as it sounds I wasn't aware of this before I bought one but thought it's worth mentioning.
If you want decent noise just get catback. Intakes without mapping give you nothing (or very little) power gain and noise will be on vtec mainly, while catback will give you noise across whole rev range. Don't spend stupid money on intake unless you got long list of mods to do and money to spend.
Or just do intake yourself like here:
Flashy, why would there have to be the need to change a coolant pipe to get the hks kit fitted? I was also unaware of this and have just recently ordered one as on my last fn2 sounded awsome. Is this because the pipe needs to be a different shape to fit the hks or? Any advice or help would be much appreciated.
Two of the oem breather hoses get replaced on install. The one from the top of the rocker cover (breather hose) has a coolant hose (small one that goes to the rad). If you look at the oem intake pipe from the airbox to the throttle body there's two hoses connected to it, the pipe to the rocker cover breather has the coolant pipe attached to it. Hence the need to replace. It's nothing to worry about
Removing the resonator and replacing with a cold air scoop (like a mock version of what Tegiwa or Mugen do) does change the exterior noise.
The note is a little deeper and you get a bit of suction noise which was absent before.
In the cabin is a little harder to tell, although one of my friends who I didn't even tell about the airbox/feed (no interest in cars, booo!) did say that the car sounded different and he was inside with the windows up.
Not sure what it would look like on the dyno, after a month or so the car is still driving beautifully, so I can't say that it's done any harm! I think even HKS doesn't make much difference on the dyno without a tune.
I did think about HKS since nearly everyone and his dog on here can't plug it quick enough, however the noise seems to be the main selling point, and I think a future Martelius addition is going to drown out any intake noise...