Maybe this has already been discussed...but if you look closely at the air intake on the 02 max, it seems to get pretty cool air from the front of the car. It *almost* has a ram air look to it. As the car picks up speed, it's pretty much getting ambient air temps due to the placement of the intake at the front of the hood. So unless you get a CAI, wouldn't just a K&N filter give you similar gains to a berk/frank short intake...especially on a hot day. Those intakes are sucking total engine heat...

 

Thank you DrVolk! That is exactly the reason I've got my stock setup
with a K@N drop-in. I went to clean my engine cover yesterday afternoon around 3:00 PM (90 degrees out)and when I popped that hood it was like a volcano spewing out hot air. Everything in the engine bay was scorching! I wouldn't dare let a filter hang out in that oven! The only option IMHO during 90 degree weather is a true, fender mounted CAI that requires cutting, which also comes with disadvantages so I haven't done that yet. When the cooler weather gets here I will put some form of intake on, but for now, the stock setup is probably the best thing.

Jesse

 

You have a point DrVolkl. The stock intake has several advantages. First, it's completely isolated from engine heat. Second, it's drawing air from a cold air source. Obviously those are both good things. The drawback is the convoluted way air is drawn through the intake. The design of the intake is somewhat restrictive, particularly when compared to the design of any of the aftermarket intakes. Ultimately, more air is made available to the engine with an aftermarket intake than with the OEM intake . . . or so the theory goes.

Remember that HAIs suck hot air into the engine only until the vehicle starts to gain speed. When the vehicle is moving, air circulation carries heat away from the intake. At speed, a CAI theoretically has no advantage over an HAI.

FWIW, I'm still a big fan of the OSCAI with a K&N Panel Filter. It's hard to argue against it given the number of MAF sensor failures we've been experiencing of late. (It's a whole lot easier to swap out an air filter than an entire intake if your MAF sensor blows up.) You'll notice, however, that I'm running a Berk Tuning Intake. There's just something about the growl that intake produces at WOT that floats my boat!

 

So these big dyno gains by the CAI that you see...is this because they don't blow fans at the HAI while being dynoed?

Back to the restrictive stock air intake...so wouldn't a K&N solve 90% of the problem??? Or would it still fall short of any sort of intake....

 

Actually, CAIs don't show big gains over HAIs on a dyno. In fact, HAIs often outperform CAIs on a dyno. The reason for that is because the hood is typically raised during a dyno run. As a result, the heat has someplace to escape to. And fans are also run to imitate air flow.

A K&N will solve some of the air flow problems. But it won't reduce the restrictions inherent in the design of the OEM intake.

The bottom line is, you need to justify your decision not to run an aftermarket intake if you don't want to, DrVolkl. There are plenty of good reasons for not doing so.

 

I started something similar to y2kse...I had OSCAI and then change to berk intake. the Stock air scoop and air box acts like a heat shield by closing the entire intake from hot engine bay. However, the problem with stock air box is that it doesnt completely use the panel filter....if u take out the drop-in...u can see the corner is dirtier and the other side is cleaner. For mine, I only see dirt on 1/3 of the K&N drop-in. That's why the stock air box is restrictive.

a good intake will tend to eliminate turns on the tubings in order to maintain air turbulence. (why the stock air box is restrictive again!) That's one of the arguments of CAI where the tubing is too long and too many turns. But the down side of HAI is hot engine bay will pack a lot of hot air into the filter...where the engine gets smaller volume of air.

guess the opening on the Subarus hood does do something.

 

yes, it is sucking in hot air as the car is idling until maybe about 10mph+, fresh air will come in through the stock scoop and the oscai tube(for those who have the oscai setup, you know which tube.) I just bent it right under the filter. besides, the % of car moving is much more then just idling. i think i'm making sense?

 

I'm not trying to justify anything...just curious. I've put intakes on cars of mine before...but I've never had a car with such an interesting stock intake setup. Just trying to figure out where to spend my $$. Seems that people are very quick to slap on whatever mods they can get their hands on without thinking sometimes....so I'm just wondering if a simple K&N is going to give me the power I want. Sounds like it gets you about 1/2 there. It also seems that CAI aren't really worth the extra $$...but who knows. The K&N of course won't give you the great sound that the berk/frank/others give....and I also suppose removing all that silencer crap is going to free up some weight, which is always nice.

I dunno...I've been reading everything about intakes for the past 2 months and I still can't decide which is the best way to go.

 

I'm personally gonna pick up a K&N drop-in filter at the dealer when I take it in for an oil change tomorrow. I just don't want to risk the MAF problem(s), and personally I kinda like how quiet my engine is. It makes it easier to surprise the Hondas hehe.

 

I have been perfectly happy with a drop in for 22,000 miles now. I still am not convinced about any real gains from an intake (under hood) on a performance basis. People have talked about .2 sec over the 1/4 mile. Crap, a mild headwind, etc. can account for/eliminate that.

I agree, keep it quiet!!! It is alot more fun to blow by someone and they don't hear you coming than it is to growl like a badger in heat just to lose to a sleeper.

 

Well, the air ducts leading from under the hood to the stock airbox could easily be routed and opened wider at one end to direct cooler air toward the filter on a HAI right? I think it's time for a Home Depot run, I'll let you guys know if I can figure anything out. I think that may work very well, and leave out the need to punch a hole in my wheelwell or have my filter so low in the engine bay....

 

Well whatever you do, just don't get that "Tornado" fan thing from the infomercials!

 

Very true. I just got done reading 15mins worth of blown MAF posts. Yikes. Seems the 2k2 is especially fragile. However, to sum it all up, no one knows why they drop dead. However there is a trend, with drop in filters coming in 2nd least likely...behind no mods whatsoever. So, since I don't want to get stuck in the middle of no where, looks like k&n is the safest way to go for now. Other mods? Pulley? Exhaust? I was really hoping for the intake, but now I'm scared.

Where's the best/cheapest place to get a K&N drop in filter for the 02 max??

 

I currently have an oscai intake(see home page) and am trying this:
Instead of piping the cold air into the bottom of the stock air intake, make a square(I have no idea why nissan chose that shape) adapter and pipe it straight into the air filter box, removing more restrictions and turns the air has to make. Or modify the stock filter box to accept my 3" dryer conduit directly, that way it does not have to squeeze thru the square one on there already. And possible move the "hole" more centered on the air filter to improve filtration and flow.

FWIW, I don't think K&N filters are worth the money. I read a study on a BMW site about how they had oil tested over 6-7 oil changes(same car), half with a BMW OEM filter and the others with a K&N filter. The K&N filter let in almost 7 times the carbon(found when testing the oil) and other contaminents. For me, it is really not worth the .025 hp that a K&N filter would give, especially since I plan on putting 300k+ on my motor. If I find the link for the study I will find it as it was very well put together and informative

 

I've been thinking about this for awhile. I've got a stock air scoop attached to an OSCAI that for all practical purposes is useless with a Berk Intake (or any other HAI for that matter). What would happen if you enclosed the cone filter in an airtight enclosure and ran a tube connecting the enclosure to the back of the stock air scoop. Wouldn't you effectively get all the advantages of a CAI that way? And by enclosing the air filter, wouldn't you also eliminate heat soak as well? And wouldn't doing something like that be WAY more effective than building a heat shield that would still allow some engine heat to raise the intake temperature.

I dunno, guys. Maybe we're thinking too hard about this when the solution is right under our noses.

 

Not sure about cheapest, but I picked up mine for my 2001 at Autozone for about $45.00. Try them online.

 

I've been running K&N drop ins both on my 2K2 and my previous Y2K , and the performance gain is not vey noticeable. The main reason I run these filters is that they are low maintenence and last 100K miles. They pay for themselves after 30K miles (after you would normally go through 3 paper filters). I've had no MAF problems, no check engine lights, nothing out of the ordinary.

 

...We're talking about two different things my brotha'... The K&N we are referring to is the air filter not the oil filter. Many of us use a K&N air filter drop-in panel that replaces the standard 10k mi. paper filters that you change out all the time... The K&N can be cleaned and reoiled for 100,000+ mi. of use, and it costs $40-50 depending on where u get it. There is some claims by the company that K&N air filters are less restrictive for air flow into the intake than a paper filter.... But it probably doesn't make much difference... I just use one because of the longevity, not having to replace those weak paper filters every other week...