K&N Cold Air Filter gains

[SpeedRacer]

I have a friend who says that K&N air filters are just a gimmick and are a waste of money, especially the cold air intakes.

I however think he is just full of it Do you guys get K&N air intakes all the time or do you usually buy a different brand? I've tried a ractive filter in my car but I swear its not as good as the K&N filter I picked up.

Wondering if you guys recommend always getting the cold air intake over the short ram intake or just plain cone filter. I just have a short intake on my car now, didn't think the cold air intake is worth the price of admission

[Junior]

My preference is to always get the cold air intake kit if available, and from K&N. They always seem to have the best fit and manufactured the best with good quality parts.

[Paul]

Cold air intake and if not available, then short ram and then just the filter drop in.

And as long as you buy a good brand, K&N, ractive, etc. that seems like its good build quality you shouldn't worry.

[cbishop11]

So, as far as K&N goes, they are typically hard to beat as far as improved air flow to the intake. However, they are made of cotton fiber and oil, which is not so great at trapping small dirt particles. There are a number of articles proving one way or the other that these type filters are adequate for dirt filtration. You just need to read them and decide for yourself. There are foam filters (and those are the ones I prefer) that claim better filtration and similar if not better air flow to the cotton-oil types. Do some research and figure out what makes sense to you.

You must be careful about what you buy when a vendor is selling a "cold air intake" many times these intakes are just a cone filter with an air dam around it, that is supposed to block the hot air from the engine. However, the engine will always be sucking enough at wide open throttle such that there is no way it wont pull in some of this hot air. Ive done a few experiements with a thermocouple using a cold air intake, like that one I described, and a stock air box that was ported to allow more air (with an additional hose ported to the fender well). I ran experiments in stop n go traffic, highway cruising, cold starts, warmed up, etc. In every case, as soon as I asked the car to accelerate it would ingest lots of hot air with the "cold air", and none with the factory box.

Basically when looking at the kits, you need to ask yourself is the filter sealed away from possibly sucking in hot engine air. I definitely would not buy something with only a cone filter, and no dam at all. That would be worst case.

[Tureno]

Wow this guy seems to know what his talking about!!! Hey which brand air fillter do you use then? I might get one that you have

[cbishop11]

On my Tundra, I use TrueFlow's filter along with their intake kit. The filter is a foam drop-in replacement.

However on my MR2, I was quite limited on the shape of the filter I could choose from. For fitment, I had to choose a cone filter that is jabbed into one of the side vents. This was the best fit I could find for cold air in the space I have, especially considering I have a huge air to water intercooler sitting right above the filter intake. Yes, I know this goes against my own advice, but in this case, I had to make some compromises for fitment. Placement is not so bad, since it it placed in a spot where airflow will push cool air past the filter and keep hot engine air (mostly) away from the filter. From monitoring my air intake temps, I typically stay at ambient temps, and under boost I only see temps rise about 10C. So all this really says is that my intercooler is doing a great job of removing any heat introduced.

The filter used is one sourced from Turbohoses.com



edit: just to clarify, the experiment I did in my previous post was not on the MR2, but on a supercharged Harley Davidson edition F150 I used to own.

[Junior]

That is some great info, thanks cbishop!!

[JonFT86]

How often do you find yourself cleaning the filters or changing them out cbishop?? Do you use the same kind of cleaner that K&N filters use or just flush with water?

[cbishop11]

Usually the manufacturers recommend every 50k miles or so - I guess this would be fine for a daily that sees highway miles only and no offroading. When I have cars that sit in the garage for weekend stuff only, I typically clean them anually, when I do other maintenance items, but that is only because I am anal about all that stuff.

For cleaning, I buy the cleaning kits made by the manufacturer (K&N or Turbohoses or whoever), not just run them under water. The oil solvent really does a good job removing lots of dirt vs just plain water rinse. However, I will say that the chemicals from both K&N and Turbohoses seem to do the same job. They even smell the same, so I would guess they are the same chemicals, just a different color.

[car_crazy]

I have a friend who says that K&N air filters are just a gimmick and are a waste of money, especially the cold air intakes.

I however think he is just full of it Do you guys get K&N air intakes all the time or do you usually buy a different brand? I've tried a ractive filter in my car but I swear its not as good as the K&N filter I picked up.

Wondering if you guys recommend always getting the cold air intake over the short ram intake or just plain cone filter. I just have a short intake on my car now, didn't think the cold air intake is worth the price of admission

in a way your friend is right. some "cold air intakes" are nothing but a gimmick. but there are a lot of them that are not. cbishop11 already covered a lot regarding intakes. i just want to add on top of what he already said.

first thing you need to decide is what kind of intake you want.

Short ram intake - delivers air quicker due to shortened intake piping. which improves throttle response by a bit. still sucks in hot air though.

Cold air intake - sucks in colder air. usually by placing the intake far away from the engine(like in the bumper) or by sealing it in a box that acts as a heatshield.

Ram air intake - very similar in theory to a cold air intake. however the intake is still near the engine but enclosed in a sealed box that acts as a heat shield. that box is usually connected to a pipe of tubing that is routed towards the front of the car. therefore sucking air directly from outside of the car. this intake greatly improves your cars top end speed.


next thing you want to figure out is what kind of filter to use.

cotton and oil - has best filtration due to the oil and also good airflow. keeps your engine clean while providing a performance boost. also very easy to maintain. just wash with some cleaner and apply a small amount of oil(k&n offers a cleaning kit with air filter oil in it)

foam - has good filtration and provides better airflow than cotton and oil. it lets more dirt in compared to the cotton and oil filter. also can't reuse. once its too dirty you throw it out. unlike the two other types of filters.

stainless steel mesh - theres only a few companies that make this kind of intake. one of them is Blitz. this has very little filtration due to the steel mesh. but has the best airflow. that steel mesh also reduces airflow turbulence greatly compared to the two other types of filters. also cleaning this is extremely easy. just use soap and water(preferably from a high pressure hose) and let it dry properly.

[Microcosm]

On some cars, I've just used the replacement K&N filter. On others, I've installed a CAI with the K&N. Though I don't have any concrete proof, it seems to me that most of the improvement comes from the lower restriction filter than the different piping. Just my $.02

The biggest issue with a K&N "type" filter is putting too much oil on after cleaning and having that mess up your MAF sensor.

[car_crazy]

^i had that happen to me already before. i thought all the excess would dry up but it just clogged the filter and made my cars idle all wonky. i cleaned it up again and put the right amount of oil plus used carburator cleaner on the maf and everything worked out fine.

[levin]

injen aem fujita!

[scion-guy]

custom air intake FTW! if you have all the right resources and all it will work out much better. I hate paying $400-500 for a CAI that only increases my HP by 5-10.

ARC made some good stuff, too bad they went bankrupt.

[import_nation]

ARC went bankrupt?! I have a bankrupt shift knob.