Air intakes (Fact VS. Fiction)

  1. #1
    Sorry if this is a repost. I found this on the net and thought it might be useful for anyone regarding information about air filters.

    By Eric Lukas

    Many aftermarket companies claim that replacing your factory airbox with a cone air filter is the best "bang-for-your-buck" performance modification you can make. So is it true? I uncover the secret...

    What an intake does

    Your engine needs air and fuel to function. When you press the accelerator you are letting fuel and air into the engine. The combination allows the engine to create power. The waste is then disposed by the exhaust system. The more air your engine gets the better it will perform, especially if that air is cold. Now most of us don't want to bother with the cost of forced induction units (turbos, superchargers, etc) so we use the next best thing, a performance cone air filter. A performance air filter replaces the factory air box and allows the filter to be directly exposed to air (the factory airbox has a highly restrictive filter inside). This allows the engine to receive more air, thus you get a better performing engine.


    The general assumptions Most people say the performance cone air filters will raise performance slightly. Select groups of people say K&N filters will provide no performance gain or even a performance loss since they suck in the hot engine air. Some people even go as far to say performance intakes hurt the engine since they may let in more dirt than stock filters. What is true?


    The truth

    The truth is with a performance intake you WILL lose power in stop and go traffic. The reason for this is simple. By creeping along for 30 or more minutes at 45 MPH your engine really heats up. Since you are going slowly at an unsteady rate, airflow into the engine bay is very erratic. This will force the air filter to suck in the hot engine air. Since hot air is less dense you will lose performance. However, on short trips, joyrides, or highway travelling, you will gain performance since there is a consistent cold airflow into the engine bay.


    Is it worth it?

    Many people including myself say YES! You may lose performance in rush hour, but are you really looking for more power when you are creeping along in heavy traffic? I doubt it. When you need that extra performance the performance air filter will give you that fun factor.


    How can I get the most performance out of my air intake

    Most people will find that the performance cone air intake provides amp performance. However, others may want even more performance. How do you do this? By adding a Heat shield.


    Heat shields

    The best way to maximize the performance of a cool air filter is to build a custom heat shield. This will allow your air intake to suck in cool air all the time. Some companies make them but they are expensive, and you can easily build a better one yourself with less than and a trip to the home depot. What you want to do is isolate the cone air filter from the rest of the engine bay. This will protect the filter from the engines hot air. It is best to close off as big of a space as possible to allow the enclosed area to hold more air (more air = better throttle response). Enclosing an area that doesn't have any place for the outside air to enter will still work, but it is best to enclose an area that has access to the outside air. I.E.. It is best to build a three-wall heat shield that is open in front to allow air to enter the area through the front grill. If this is not possible add a ram air system.


    Building heat shields/RAM air systems

    To build a heat shield go to the home depot and buy a sheet of aluminium. This makes the perfect material to make a heat shield from since it is lightweight, heat reflective, and can easily be shaped and cut. While you are there you might also want to pick up some hardware and aluminium tape. These materials will come in handy when it is time to securely mount the heat shield in the engine bay. Start by surveying your engine bay. Get an idea of how you want to enclose the air filter. Remember to leave the air filter as much room as possible since more air means better throttle response. The more isolated the area is the better! Experiment with cardboard cut-outs first to create the perfect design. Once you have cut out a cardboard shape that is near perfect, cut out a replica aluminium sheet. Mount the aluminium sheet in your car, and you have a cool air intake!

    If you are one of the unfortunate souls who had to create heat shield with no openings to the outside airflow, it is advisable you add a ram air system. Go back to the home depot and by an aluminium duct. They have many sizes so your choices are endless. Route the duct from the heat shield to a spot that has an opening to the outside air. Secure the connections, and you have a ram air system!


    Before you buy (Don't believe the dyno!)

    Many companies claim to produce the best intake available. Most do this by providing no data, fake data, or fake dyno tests. One company has a car up on a standard lift and claims that it is a picture of a dyno test. Complete BS! You will have to decide what the best intake is, as I cannot give you an answer since I have not tested all the intakes. I can tell you to be very careful though! I would stick with a well known/recommended company (like K&N). Many companies will try to sell you one size fits all air filter kits. These will give you headaches. Some other tricks are to market accessories for your intake like carbon fibre piping (pointless) or a fan (also called electric supercharger/hypercharger/wind charger). These fans do not work! First of all they do not force air into the engine like superchargers and turbos due. They simply blow air into the engine. Whatever little performance is gained by this will be lost as soon as the fan motor heats up. Why? Because then the engine will be, you guessed it, sucking in hot air again. Why do superchargers and turbos work if this does it not work? Superchargers and Turbos force air into the engine at levels from 6psi-15psi. A fan can not come near a fraction of the pressure a supercharger/turbo creates.
  2. #2
    Good stuff mate. I may make one myself because I love the roar of my K&N and it would probably look cool too. Just need to find some piping to get the cone to the front now
  3. #3
    I used s/s flexi exhaust to get mine to front of car if thats what your thinking of doing
  4. #4
    Yeah we had this conversion before mate, you couldnt find where you got the stuff from IIRC
  5. #5
    I remember now, you've changed your avi
  6. #6
    guess what I've just found
    FLEXI
  7. #7
    Quality, i will get myself some of that soon. Cheers mate

    I would give ya rep but it wont let me
  8. #8
    thanks for feedback possi. hopefully this will stop the forum from getting clogged with air filter type Q's!!
  9. #9
    Quote:
    Originally Posted by PosiWestcoast
    Quality, i will get myself some of that soon. Cheers mate

    I would give ya rep but it wont let me
    not to worry mate got to share it about first lol
  10. #10
    ...the guy forgets that on short trips the engine will probably be cold and therefore wont be operating at full power anyway - once it gets warm it'll be super shite again
    Below 45mph (as he says) they'll be sucking in mainly hot air, therefore 0-60 times will be worse and any form of town or country road driving.

    Open inductions are still shite regardless
  11. #11
    Quote:
    Originally Posted by adsayer
    Open inductions are still shite regardless
    Agreed !!!!!

    You just cant get it throught to people though, i thinks its because they are MAX POO readers !!!!
  12. #12
    Good little post there
  13. #13
    Quote:
    Originally Posted by Y4n
    hopefully this will stop the forum from getting clogged with air filter type Q's!!
    Not a chance of that people dont understand the word "SEARCH"
  14. #14
    Quote:
    Originally Posted by Ry_B
    Good little post there
    thanks
  15. #15
    You won't notice the difference of a few bhp here or there unless you live on a track and for the noise they make it's worth having it on, good little mod with a cold air feed, enough said!
  16. #16


    they're shite.
  17. #17
    Quote:
    Originally Posted by Ry_B
    You won't notice the difference of a few bhp here or there unless you live on a track and for the noise they make it's worth having it on, good little mod with a cold air feed, enough said!

    Do you read MAX POWER ????
  18. #18
    Quote:
    Originally Posted by DAZ1985
    Do you read MAX POWER ????
    No. Do you see a shit bodykit on my car?
  19. #19
    NO because i cant see your car !!!

    I know for a fact you dont quite know as much as adsayer and yet your claiming you no better
  20. #20
    In my experience, a cone filter coupled with a cold air feed definitely improves throttle response and a lovely noise.
  21. #21
    i guess people are just after the roar from an open filter! Personally, i've only got a 1.1 and i'm happy with the standard air box. I dont see any point in tuning such a small engine in the first place!
  22. #22
    Quote:
    Originally Posted by Y4n
    i guess people are just after the roar from an open filter! Personally, i've only got a 1.1 and i'm happy with the standard air box. I dont see any point in tuning such a small engine in the first place!
    i've always thought it a bit daft to lose power on pretty powerless engines for the sake of some noise thats makes it sound like it's more powerful than it actually is.

    just me i guess
  23. #23
    i'm sure there was a guy (with a vts) on here who ditched his cone filter for his standard air box because he found out he had lost a bit of performance!
  24. #24
    But now I'm considering doing a web page and posting a page about...

    Ebay Resistors - The truth

    and then go on to say how they are in fact mint and wont bugger up the engine and you'll get billions of hp out of the engines.

    Then do a search a few days later to see where it gets copied and pasted on to a forum as 'The Truth'

    ...basically all im saying is, just because it came from a website and his first name is Eric it doesnt mean he right.
  25. #25
    Quote:
    Originally Posted by Y4n
    i'm sure there was a guy (with a vts) on here who ditched his cone filter for his standard air box because he found out he had lost a bit of performance!
    it wouldn't suprise me dude
  26. #26
    I have an open one, and i like the noise. I dont give a fuck about 0-60 times because i am 17 and i have a 1.4, which could be easily beaten in acceleration by most transit vans. But evertime i accelerate i get a nice roar so im happy with it, even if i had a BMC its really not going to make that much difference. Plus apprently the 1.4 is a shite engine to tune even if you wanted to. That is all, i did actually care about speed till recently but its fucking pointless the 1.4 is slooooow. So i may aswell enjoy the roar
  27. #27
    Quote:
    Originally Posted by PosiWestcoast
    I have an open one, and i like the noise. I dont give a fuck about 0-60 times because i am 17 and i have a 1.4, which could be easily beaten in acceleration by most transit vans. But evertime i accelerate i get a nice roar so im happy with it, even if i had a BMC its really not going to make that much difference. Plus apprently the 1.4 is a shite engine to tune even if you wanted to. That is all, i did actually care about speed till recently but its fucking pointless the 1.4 is slooooow. So i may aswell enjoy the roar
    Here, here!