My personal experience with the intakes is that you don't get a major sound increase unless you have some exhaust mods in there as well, especially at low revs. That was the case with my FX as well.. This is the same thing apart from the obvious air suction noise and the whoosh that comes from the DV hose when I lift off from the throttle. I didn't go past the 4000rpm mark yet so can't say anything for the high rpm sound yet..
One more thing on the sound is that with all the plumbing we have here, there's no direct (or even close) connection to the intake plenum, which is the source of the sound as it's right above the heads. That means, you shouldn't expect a good sound increase with an intake on an engine like this. Here are some points on the intake & install though:
- You just need ONE 60 degree bend. This can be plastic or aluminum. Just don't use the home depot plumbing PVC pipes
You can use a 45 degree bend as well if you'd like the filter to stay closer to the left.
- There's the Diverter Valve connection at the upper bottom part of the box. When you take out the box, which contains a muffling section for the pressurized extra air that the DV kicks out with each throttle liftoff, you'll need to disconnect this
- There is a clip on the right side that works as a hose organizer. Disconnect this by squeezing the sides as well
- The front air scoop also gets disconnected easily by a flat tip screwdriver
- The tubing diameter you'll need to use is 3.5" BUT the top connection has a thick plastic inner seal that prevents the 3.5" tube to slide in directly. You can either take this off and use some teflon tape for sealing (as I did) or use 3" tubing all around
- Finally, when you take everything out and completed installing the intake, you have to take care of the DV outlet hose. More detail on that below:
The Diverter Valve is a diaphram that releases the accumulated pressure in the intake system everytime you take your foot off from the throttle. The X6 intake box has a separate smaller section at the back that mutes this pressurized air and cycles it back to the intake. When you take out the intake box, this hose will be open and if you keep it that way, there will be a big WHOOSSH sound every time you take your foot off from the gas. Some like this sound but I personally don't so what I did was to use a breather filter on the tube. The jaggy inside of the filter silences the whoosh sound and prevents dirt to get inside. Now, I can only hear a fainter whoosh when the system is loaded, like when going on a single gear on a hill. If you'd like, you can attach this hose back to the intake tube by drilling a hole in the tube and using 2 hose fittings. Just make sure to measure before doing anything.
For now, I used cable ties to stabilize the intake and DV filter but it's a temporary solution. I have some metal mounts but I'm thinking about using a semi open filter box to cover up the filter a little so that will be for another time..
PS: It's too early to see a performance gain as well. The ECU needs to adapt to the extra air first. More on that later too..