Changing filter on CAI


Founding Member
Sep 25, 2001
I remember reading a few threads a while back about people dumping the filters that come on the JLT CAI for a better filter, I cant remember the companies name. Hoping one of you can.

Ive also seen some talk about a bigger MAF for these intakes as well. What does the JLTII come with, compared to what you can upgrade too?

  • Sponsors (?)

I've heard the K&N filters aren't that great. Some guy posted this link:

Why is cotton gauze a BAD material? | R2C Performance ... World-Class HIgh-Performance Intake Systems & Filters


:lol: Yup, me :D

I have done a lot of research on filters lately. Not dyno test or street performance obviously because then I would have to buy one of each and they each cost around 50$+-. However, most of the higher horsepower gains from filters are from less restriction(ie cotton, gauze etc.) The lower hp numbers are from higher restrictions, but these are the best at efficiency(ie dirt capacity, trapping etc.)

So in my opinion, my opinion mind you and I have no dyno numbers or years of engine tests to back it up, I think the filter depends on your climate and use. For me, I live in the desert so I want to go with an R2C, AMSOIL ea nano or something of that nature. Sure it's high restriction, but it's lower than stock by a little and still gives 99% of the stock filters eff rating. For those of you that live in clear air then K&N, Green, Blue, Purple, Orange, etc.:)p) as they would be the best and you wouldn't have to worry about dirt as much as I do per se.

I would put a high restriction high efficiency filter on my car no matter where I lived though... 32k$ is a lot to invest and I don't want to throw that away just because I bought a 'performance' part and it ruined my engine over time...
Right now I have a K&N drop-in filter.

All this talk about filtration has me wondering if I should go back to an OEM paper filter?

I guess I'm wondering how much damage "dust" can do to your engine? I live in the "Detroit" area. I have 47K miles on my car. On my old Civic Si I had a REAL CAI (filter in front of the front wheel behind the bumper)...and put 130K miles on the car.

I mean, during normal driving your engine really gonna blow up from using a K&N filter? With my drop-in filter, I've seen about a 2-4mpg increase over stock...better throttle response, and prolly not much HP gain. But the MPG increase alone, I think, was worth the price of the filter.

But if the filter doesn't FILTER very well, I don't wanna trash my engine.

So. Question:

Would you go back to OEM paper? If I get a CAI/tune this summer, should I toss the K&N and get something else?
:shrug: Ultimately that's your call! If it were my car, I would go with the OEM paper until I could afford an AMSOIL Ea filter or something along the lines of R2Cs filter. I won't get the mpg increase as much per se, but I feel safe knowing that my air filter is doing what it is supposed to: filter! Now oil filters are fine for a while, while they are oily :p That's when the dirt sticks to them and you have filtration, but like that article I posted, how much filtration are you getting from gauze? Again ultimately it's up to you.

Dirt is extremely dangerous to an engine, maybe more so than before. Think about it. There is tighter tolerances and very little slop. The parts don't really need to warm up to seal everything properly as it is already sealed. I mean my GT came with semi syn oil and they asked me right off if I wanted to switch it to full syn! That's unheard of in older vehicles because there had to be a break in period and then you had to get a certain weight etc. Whew rambling sorry... So imagine all those tight spaces and clearances being rubbed by dirt that came in through your filter... It's like a really fine sandpaper all over your engine. Is it going to happen? Yes, it's unavoidable, but you can control how much dust/dirt and what size gets in. Frequent oil changes help to keep the dirt and dust from accumulating too much. Obviously in Detroit there isn't as much dirt as me out here in the desert, but nonetheless.

So again if it were me, I would ditch it and get one of the above mentioned, even the Bullitt CAI comes with a paper filter that I am sure you could adapt. Or another option is to ask the CAI dealer that you plan on going through if you can just get the pipe and MAF and have them hold back the filter. See if they will knock a few bucks off, worth a shot and you can use that money for the filter you want. R2C doesn't put their prices online and the AMSOIL filter is 47$, I don't know about the Bullitt one, but probably about the same. So as a comparison the K&N drop in is 45$. So you are spending the same amount of money really, but actually less because you don't have to buy rechargers and mess with the oil...

Forgot your original question... You will probably be fine with the K&N til summer. I would change it after that though :p I wouldn't change back to the paper and get rid of the K&N. I mean when is the last time you cleaned it? if it's been a few thousand miles just open the airbox and see what it looks like. Really dirty, clean it. semi dirty you could wait and if it's clean, well lucky you!

No everyday driving won't blow up your engine. I am just talking about ruining your engine by slowly wearing it out with excess dust and dirt. Obviously that will take some time, like a few years, but yes it will take away performance eventually, blow up no!

Good luck in your decision!