Intake filters...

Methodical4u

I've noticed that out of all the filters i've looked at such as the R2C, the K&N and a few others the filter is flat and not open on the end. I remember seeing a few filters that were open on the end and the sides. I would think having a filter that would suck air in from the front as well as the sides would make more power wouldn't it? The G3's sit flat so I can understand why they would be flat... but the others? Hmmmm

370z1

I haven't seen any stock drop in filters other than flat because of the mounting deign NISSAN uses. Only option I am aware of is to buy an intake kit or a DIY mod.

I was debating on saving up for the Stillen gen 3 or K&N intake kits but prior to spending that much I am test driving a lower cost option and will see how it goes. Stock drop in air filters like K&N are good which can be used with the stock air filter housing which will keep the air temp a little lower compared to an exposed filter (the colder the better) however stock filter allow less CFM flow. I haven't had the chance to dyno mine with these changes but I do notice a gain just can't say how much.


Here is what my experience is thus far. I changed out the factory air paper filters and housing with the Spectre cotton fiber cone filters purchased from the local auto parts store. Total cost for filters and material was about $120 bucks and the total time to perform the mod was about 2.5 hours. All factory parts kept intact for reuse.

I also am using the tune provided with the HyperTech Max Energy Sport programmer to help make use of the extra air volume. Ideally I would like a dyno down the road to get the best air/fuel map to compensate for the change.

To get the filters to mount correctly I had to buy an air intake tube extension and cut length to size. Then had to router our a rectangular hole to mount the air temperature sensor(s). If you do it yourself and don't buy a pre-fabricated kit here are the things to be aware of.

1) If you start the car prior to finishing the install with the Air temp sensors not mounted it will stall the motor and trip the check engine light. Once the air temp sensors are mounted again the engine will run normal and the idle and ECU will readjust after about 5 seconds. However the check engine light will remain. To resolve this simply disconnect the pos battery terminal for 5 minutes and it will clear it.
2) As a result of removing the pos bat terminal the Automatic UP Window control upon closing driver and passenger doors will no longer function which means when you open your door(s) the window(s) will increment downward never going back up after doors are closed. To resolve this you can take these steps.

A) Turn car to ON position without starting and put windows in down position (ie: open) and then turn ignition to off position.
B) Turn car to ON position again without starting and close the driver window and continue holding upward for 4 seconds after window is all the way up then turn ignition off. Repeat same steps for passenger window (from the driver side control).










If you just want to replace the factor air filter and leave the housing in place I have used this K&N air filter prior and it was a good replacement.