Fairly new to the forum but have been tinkering around with my new to me Micra for a couple months now. Its a white 2015 SR 5sp picked up from Quebec end of June. Needless to say I hate stock air boxes, they are hideous to look at and perform for the most part poorly to a real CAI.
I googled for many hrs on best setup and tubing however I could not find 1! True CAI documented on the internet, maybe Im a bad searcher? All I could find was overpriced hot air intakes as I like to call them Lol. Anyway I fabbed up one for pretty cheap and so far performs great compared to the cone sitting right beside the engine. Here I will document what I used and where I got my parts from and a small diy:
1x - 2.25 to 2.5 reducer coupler $23 - mishimoto-Amazon
2x - 2.5 coupler $25 - Toronto turbo
2x - 90 degree 2.5 aluminum elbow $50 - Toronto turbo
1x - 45 degree 2.5 aluminum elbow $25 - Toronto turbo
1x - generic cone filter $20 - Amazon
1x - valve cover breather $10 - Amazon
6x - 2.5 or greater worm gears - free cause I have lots!
Total coast around $150 give or take on where u can find best deals. I got tubes from Torontoturbo.com and rest off of Amazon.
I also harnessed my maf sensor plastic piece from the old airbox and siliconed it with high heat silicone to the primary 90 degree aluminum tube off the intake. I could not find an adapter nor did I care for an aftermarket one as harnessing the oem is free!
Rotor tool with cut off disk
Grinder with thin cut disk
Clear high heat silicone
220-400 grit sandpaper
Torx bit - unsure size
High heat silicon
Fairly straight forward, remove all the oem air filter housing, to do this properly you do need to take off the bumper, bumper, 2x 10mm at the fenders, 7 push clips, 5 by the rad and 2 under car and 4 torx head screws that attach the bottom of bumper to the plastic garnish under the car
Once bumper is off there is a plastic shield inside driver fender lining, and a small oem plastic tube to feed cold air to the stock air box. You will need to remove both of these to route new tubing and for clearance on the cone filter when installed.
Once apart you need to harness your old maf housing from the stock airbox. I do not have pictures on this part unfortunately. Key is to take your time and always under cut to leave yourself space incase you mess up. Yes you will get tons of hot plastic shavings thrown at you! Long sleeve shirt is advised.
After you have harnessed the maf plastic you can now start mocking up the tubing. If you get your tubes from Toronto turbo you will need to cut off about a 1-1/4 off each end of one of the 90 degree tubes and the second 90 degree you will have to cut quite a bit on one end or both ends if you decide to not cut the 45 degree tube. I suggest leaving the 45 degree tube and cut the second 90 for ease of coupler and worm gear fastening.
Key for cutting and mocking the tubing is do one piece at a time and never over cut, you can always cut it more if need be. Take your time! I overall only had to make 2 cuts to the tubing as I had a spare short 2.5 90 I had laying around.
Once all mocked up take your maf sensor and a sharpie and outline the bottom of the maf sensor onto the 90 degree elbow, I cut this rectangular whole with a grinder then bent the small pieces out then filed and sanded down said hole that was just cut.
After that and your all mocked up and everything is cut you gotta file down and sand your cut tubes to ensure no aluminum bits will get sucked into the intake mani. Once sanded and filed wash with dish soap and let dry.
Once dry grab your 90 tube with maf sensor hole and silicone the harvested plastic piece to your tube. You will want this to cure for a day to be on safe side. I used permatex clear high heat silicone. $10 at crappy tire.
Now the fun part, take all your cut tubes, couplers and worm clamps and assemble it all together! End result will be the 2 pictures I posted. If you need help or Im unclear on anything shoot me a msg or reply to this thread. I will try my best to help anyone who needs it. Im also doing this off my phone so forgive me for any grammar or sentence errors!
End result is a very throaty deep sound. Sound hits a lot lower in rpm then a short ram intake!