k&n air filters

metamorphpwner · 11 Jul 2011 at 16:54

Bat said:
Air filter performance varies depending on the car/engine/bay layout etc.

It's not correct to say cone filters are rubbish full stop. The tests done in the thread I linked to showed a marked improvement using a cone filter over a standard airbox setup.

My advice would be to read up on what people have spent a fortune trying out on the car you have!

on a Fiesta ST i've got the K&N 57I and since installing it around 2Months ago i'm seeing better MPG and also seems to have better throttle response. Not everyone will see a benefit, but it is mainly dependent on the car/engine.
no point in a K&N for a 1.2/1.4/1.6 IMO.

Dogbreath · 11 Jul 2011 at 20:35

MOOGLEYS said:
Also heat soak is a big problem, .

Why do people now use the term "heat soak" when they just mean something is "hot"? I bet very few people actually know what it really refers to...

Scania · 11 Jul 2011 at 21:37

Duke said:
As mentioned, don't bother with a cone, it will be worse.

I'm a little puzzled by this - I had an S2 (1990) Escort RS Turbo with a cone filter - and plenty of heat under the bonnet - it was fine!

ubersonic · 12 Jul 2011 at 00:46

MOOGLEYS said:
This site would claim different.

http://www.mkiv.com/techarticles/filters_test/2/

Hang on, lemme get my gun... (this test is referenced a lot on Jap car forums...)

The test your linking was done in 1999, the power gains were tested by dyno'ing a modified 1990 Toyota supra twin turbo:

The very scientific filtration tests were done like so:

Since that test was done 12 years ago Apexi and HKS have both redesigned the filters that were used in it (HKS foam filter is now 3 layers, Apexi filter looks visibly different in shape)

Original article including the 5th filter that always gets forgotten is on-line here: http://www.mkiv.com/techarticles/filters_test/1/

R420LA6X2/4MNA said:
I'm a little puzzled by this - I had an S2 (1990) Escort RS Turbo with a cone filter - and plenty of heat under the bonnet - it was fine!

The blurb that companies like AEM give for their cold air intakes is that cold air is denser so more oxygen goes in the engine, more air is better. The flip-side to this is denser air is harder to move, thus the hot air form a short ram intake moves faster, more air is better.

Thats what I read anyway, I bought a HKS mushroom intake because I like the look

Matt82 · 12 Jul 2011 at 08:39

Dogbreath said:
Why do people now use the term "heat soak" when they just mean something is "hot"? I bet very few people actually know what it really refers to...

agreed. and then the people who put a sheet of metal near the filter, as a heat shield, to stop hot air getting near it... because air being sucked in would never just travel around the shield...

The Running Man · 12 Jul 2011 at 09:38

I dont agree. as long as cold air is feeding to.the inside of the heatshield and pushing the warm air away then the heatshield will be doing its job. this is mine on the left.

(ignore the yellow/red circles)

Uploaded with ImageShack.us

sure if you have no air movement because your stuck in traffic then your engine bay is likely to ve swamped with warmer air until you get rolling. my intake ducts on the side have pipe that feeds to the filter the air should overspill and effectively push the less dense air away from the filter and away...

topshot · 12 Jul 2011 at 09:45

Who cares about heat soak if your running a cone filter on turbo car? The air is heated up before the intercooler anyway. Even on a NA car as soon as you start moving air is forced into the engine bay.

The Running Man · 12 Jul 2011 at 10:11

On my other car i run an open cone and i did on the primera tol would have preferred a heatshield.

Ideally the arc enclosed box flat filters probably do a great job!

Matt82 · 12 Jul 2011 at 10:21

topshot said:
Who cares about heat soak if your running a cone filter on turbo car? The air is heated up before the intercooler anyway. Even on a NA car as soon as you start moving air is forced into the engine bay.

two situations

1) cold air heated by the turbo, forced through intercooler
2) hot air heated by the turbo, force through intercooler

which one has the hotter intake temp in the manifold?

topshot · 12 Jul 2011 at 10:39

Matt82 said:
two situations

1) cold air heated by the turbo, forced through intercooler
2) hot air heated by the turbo, force through intercooler

which one has the hotter intake temp in the manifold?

Seriously it makes hardly any difference, i have ran both it made no difference to power etc.

By the time the air is in the intercooler its near enough the same temperature, its not like you put your open cone on top of the turbo.

s0ck · 12 Jul 2011 at 11:38

Op: unless it's free, refuse it.
If it IS free, put it straight on Ebay and then buy something that doesn't need cleaning and oiling (and potentially fouling your MAF) constantly