I'm thinking between the K&N, Apex, and the HKS Super mega flow kit..
Whats everyone's experiences with them?
And... ive already went through the search engine on the site... if that's your recommendation..

 

K&N drop in filter on your stock air box.

Everything else is crap.

 

Dunno about that.
All the stock filters I see are only dirty on about half the filter element.
Doesn't look like the stock box makes very good use of the whole filter.

 

Not if you remove the port extension and "ribs" from the stock air box. I drilled the plastic rivets off of the stock extension inside the box, and removed it, along with grinding down all of the reinforcement ribs inside the box.

It was a pure pain in the ***; understatement. Drilling the rivets was easy but all of the grinding took a while.

I ended up going cone filter and gained some top end recently, but a DD, I recommend modifying the air box. My 7 is DD and all the gains going cone filter are wasted because most of the time, I am not in the power band.

 

Just remember its only an intake..don't fall into the trap of buying the expensive stuff and spend that money elsewhere.

 

if you get a cone, just remember you are removing a stock cold air intake.

its dyno proven that you lose hp with a straight up bolt on the afm cone filter.

 

any pictures of what you did???
would like to see what you did so i can do the same

 

Buying an intake is the biggest waste of garbage anyone could spend on their car to "hook it up". Don't worry about any sort of intake besides the stock intake. The stock intake system is more than enough.

 

Unless you, build a system to get the ambiant air into it.

I really like my Apexi filter its S5 only though

 

The stock air box seems to do pretty well up to about 200bhp. After that, you may want to upgrade.

K&N - My favorite due to the long 50,000 mi service interval and 10 year / million mile filter life. Also, this brand is used by the large majority of professional race teams. Internet mythbuster: The oil from the filter will NOT ruin a mass airflow sensor.

Apexi - Exellent quality disposable filter but overrated by an Apexi-written infomercial from Revspeed Magazine that is running around the internet which many people mistake for an unbiased scientific evaluation. Internet mythbuster: This is NOT a "lifetime" filter, but rather Apexi states the typical filter life as 25,000km (15,000 miles).

HKS - Looks really good when new but starts to look dirty after about 3,000 miles (depending on your region), and the elements need to be replaced about every 10,000 miles. The hardware is excellent, and even has a hook-up for the stock air pump hose. If I had a show car I would buy this kit and an extra element so that I could keep the extra one in a bag and quickly install it at shows. Internet mythbuster: The foam will NOT disintegrate and get sucked into the engine as long as you don't do anything stupid like trying to wash it or let it sit in the car for ten million years.

Yeah, it would seem that way to the layman (and to those dipstick Australian automotive writers who got their engineering degrees from a Cracker Jack box). The thing is, the particles in the air have mass, therefore momentum and inertia, and do not follow the same fluid flow of the air. This means that if there is an abrupt turn in the intake system, the particles will tend to follow a straight trajectory path (which may actually have a bend due to other forces) while the air tends to take the turn. When the air filter is positioned after a turn or after a transition point, you will see the majority of the particles adhere to the filter where inertia takes them. Yes, the air hits this same place too, but it also follows a fluid flow as it seeks the path of least resistance, so it is still flowing through the rest of the filter. If you want to learn more about this, see the diagram of a simple inlet inertial particle separator in Figure 2 in this document.
http://www.kfupm.edu.sa/ae/fspub/200...6-0014-IPS.pdf

You can use an AFM adapter to attach a universal Apexi filter, or any other pod type filter, to an S4 engine's AFM. Most commercially-made AFM adapters are for either 70mm (2.75") or 3" inside diameter cone filters. The adapter is not required for S4 engines running with a standalone EMS and no AFM.

 

Link?

 

search for it???

 

This MAY be true on a completely stock system, but there are many factors that affect horsepower other than AFM temp. I see about 10-15C less at the throttle body than the AFM. Also RotaryRocket88 and myself did some back to back temp tests with his enclosed filter setup vs. my open filter and the temps were about 7F lower with his setup at full boost, both were logged with an Rtek 2.1 and stock sensors. So there wasn't that much of a difference, now this test wasn't done with a stock setup but I would love to compare.

 

I'm running an NA S4.
Do aftermarket intakes help more on NAs or T2s?

 

on an N/A you probably won't even notice a difference in power no matter what intake you install.

it will make the engine bay less cluttered and might make more intake noise...but that's about it.

 

See, I figured since you were so damned sure that you knew this was fact, that you'd know at least who posted it or have an idea of where to find it. Searching for something like "cone filter" and "hp" nets a ton of results. It doesn't take a mensa member to know that.

Given that you wouldn't at least point me in the right direction (given the likely hood a of a ton of erroneous search results), I pretty much have to conclude that you read this on the interwebs somewhere, and with your degree in thermal dynamics you got form reading a webpage somewhere, concluded it to be truth, and thusly regurgitated it here.

I would really like you to make me eat my words here (because i really do love it when people back up their assertions with fact and not rhetoric like "search for it???"), but something tells me I'm going to go hungry...

 

Edit

 

A race-level aftermarket intake helps a lot on NAs. This consists of a standalone EMS, a Weber type intake manifold, individual throttle bodies or a Weber carb, K&N stack filter, large housing around the filter area, and a very large flexible intake hose at the high-pressure area near the front bumper. You are looking at about $2,500 to $12,000 for such an intake.
http://www.mazdatrix.com/faqpics/roadrace/ep01123ib.jpg
http://www.mazdatrix.com/faqpics/roadp7/p7011hb.jpg
http://www.mazdatrix.com/faqpics/roadp7/p70219ab.jpg

Most of the internet "tests" are horribly flawed per the scientific method. However, I would not be at all surprised if a cone filter attached directly to the AFM would in fact lose horsepower vs. the stock system if the under-hood layout was such that hot discharge air from the radiator were sucked into the air intake. In most cases this would only be a problem when the car was parked or at very slow speed, as airflow through the engine bay tends to lessen the heating effect as the car travels faster. I don't have a degree in thermodynamics, but I do have a degree in aeronautical science. If you are interested, the calculations for relative horsepower are found in SAE J1349.

 

Not true on the Apexi adaptor. The main reason I like it that it has all sorts of brakets so that it doesn't rattle or shift. The main part only fits the round s5 AFM. This is why my S4 has a "bonez"

 

it is found that the real restrictions on a non turbo car are the airflow meter, and the 5th and 6th port sleeves, and rods.

**** it, ask rotary god what he thinks.

 

hmmm.. well my plan of investments were.
1. strutbars
2. Steel brake lines/cables
3. intake...
4. downpipe
but... it sounds like switching to a aftermarket intake is a waste of money..
and i dont think im willing to spend anything like 2,000-12,000
300$ was my limit for my intake.
well, i have a racing beat catback exhaust system currently installed if that will help me notice the difference after i switch to an aftermarket intake.

 

do it

 

get a full exhaust, and then get an safc.

 

Just out of curiosity, how did you "find" this?

I mean, just looking at the intake, the AFM would appear to be a restriction and the horrible 90° fitting into the throttle body a close second...but appearances can be deceiving.