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Anyone else is running K&N filter in GenIII?

Discussion in 'Gen 3 Prius Accessories and Modifications' started by cyclopathic, Apr 22, 2011.

  1. cyclopathic

    cyclopathic Senior Member

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    After getting Prius one of the hardest things to get used to was the "hybrid" acceleration.

    It was more sluggish when light on the throttle, but when I hammered it the car it accelerated quickly. There was an annoying 1sec bogging transition, where the ECU would do nothing before starting accelerate.

    K&N filter fixed this. After installing one at 30K that annoying acceleration delay is gone and accelerator transition from light to "to the floor" is very transparent, drama free and conventional-car like.

    Downside you have to be more restrained to get good MPG.
     
  2. adamace1

    adamace1 Senior Member

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    Sorry but I don't believe that an air filter makes the electric motors spin the ICE up to speed faster and add fuel faster the the ICE to remove that lag. It is a fact in a normal engine like the prius a K&N filter will not do anything different from a toyota filter... Well it may let in more dirt/dust but it can not improve HP.
     
  3. bc104

    bc104 Junior Member

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    I've had one in my '07 for years. I never noticed a difference. In fact I never noticed a difference in performance or mileage with the air filter change or having Mobile 1 synthetic.
     
  4. cyclopathic

    cyclopathic Senior Member

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    IMHO it has to do with programming and MAP readings vs TPS (or mass sensor - whatever is used in Prius ECU). In many transitions spinning engine from dead stop is not an issue as it is already spinning.
     
  5. JimboPalmer

    JimboPalmer Tsar of all the Rushers

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    If your engine is spinning at a dead stop, perhaps you do not have a Prius?

    My '09 accelerates just fine, my wife swears I must have modified my Prius. Your '10 should have an even larger engine.
     
  6. stream

    stream Senior Member

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    It's called the placebo effect. ;)

    I've not seen any real proof that K&N filters improve performance, and this is after many years on forums for Porsche, BMW, Mercedes AMG, and other high performance cars.

    On a Prius? Really? :D
     
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  7. mad-dog-one

    mad-dog-one Prius Enthusiast

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    Hawthorne effect for a device; placebo effect is for a medication.
     
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  8. stream

    stream Senior Member

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    Well...if you want to get picky :D the Hawthorne effect involves being part of an experiment, and is not related to a device. ;) So I'll stand by placebo effect as being appropriate.
     
  9. cyclopathic

    cyclopathic Senior Member

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    actually both of you right it cannot be neither Hawthorne effect nor placebo, by definition of both terms.

    With respect to air filters improving performance, re-read OP, there is no claim of performance increase is stated, just improvements in driveabilility.

    To prove or disprove the claim you would need to conduct blind study, which would require several subjects who will conduct tests whilst not aware which device is installed and tested. Perhaps in different conditions (altitude, temp) as they will influence ECU inputs.

    The OEM filter has been preserved, if any of you believers are willing to be a tester, that can be arranged, PM me.
     
  10. socal147

    socal147 New Member

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    When I had my Dodge diesel 2500, I tried the K&N. It was loud and let dirt particles into my intake. :eek:
    It was removed and the stock air assembly reinstalled immediately.
    Never again on any vehicle.
     
  11. Skoorbmax

    Skoorbmax Senior Member

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  12. cyclopathic

    cyclopathic Senior Member

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    Thanks for the article, good to know.

    I had K&N in 2 vehicles from new; one was traded in for Prius under cash for clunkers, with 225K on odometer, another (1.5L 4cyl) is still in service with 376,000mi. Neither of engines were ever rebuild, but after reading the article I really worry about causing premature engine failure, I will change to OEM right away, thanks.
     
  13. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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  14. cwerdna

    cwerdna Senior Member

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    Wow! Great article!

    I figured they were filters you put on in order to have MAF sensor failure. That seemed to happen to folks on maxima.org who used K&N (and/or other? aftermarket) filters when I had an 02 Maxima.
     
  15. Skoorbmax

    Skoorbmax Senior Member

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    Even before I came upon that I always used this logic when recommending OEM filters: filters are cheap and as a percentage of the price of the car the difference between simple and complex is almost negligible. It makes absolute sense that the engineers of the engine won't have cut corners in efficiency of the filter. I cannot believe that K&N knows what is better for an engine than an engineering team that created the engine, and if they were able to get better horsepower, better cleaning, better fuel economy by switching from a $6 filter to a $15 they would. It just makes no sense at all to me that OEM is not the absolute best filter for an engine made by a competent automotive brand.

    This is also why I have always used OEM spark plugs.
     
  16. cyclopathic

    cyclopathic Senior Member

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    to each his own. I guess sarcasm in previous post was lost on you, my bad.

    There was also a study done ~15 years ago which compared paper filters to cotton gauze filters (K&N). It found that while operation with paper filters was more expensive (~30,000$) it was beneficial because of longer engine rebuild intervals, 22,000hr vs 18,000 with cotton gauze.

    As a result there were numerous K&N bashing posts all over web for many years to come.

    What K&N bashers failed to see is:
    - study was done on open mining equipment, in worse possible dust conditions
    - avg speed of car on the road is 35MPH.
    At 35MPH 20,000hr will be 700,000mi. The difference of 4,000hr would be difference btw 630,000 and 770,000mi. Very big one if you are fleet operator, but how many cars have you taken to 500,000mi mark?
    - Mass-flow sensor, etc failures were traced to improper servicing (over-oiling and putting oil on in side of the filter)
    - use of K&N filters does not void OEM warranty.

    There is no question about if OEM-type paper filter filters better, question is does it matter?

    With respect to "an engineering team that created the engine" knows better comment, there are other reasons influence their decisions:
    - liability (product to account for worse abuse case)
    - cost
    - product placement in product line.

    Tell me, if Toyota Tundra engineering team knows better, why Toyota TRD sells cold air injection system for very same Tundra with oiled cotton gauze air filter? wouldn't they know better?
     
  17. Skoorbmax

    Skoorbmax Senior Member

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    Clearly. I thought no way that you're actually using the anecdotal experience of two vehicles alone to declare or not declare the merit of a filter.

    Your post references a study about mining equipment and then more anecdotes and subjective arguments. And I also had subjective arguments. So let's just throw those away. I've given you a link to objective, quantitative analysis about K&N.

    I personally won't put K&N in my cars. Neither will Toyota from the factory, nor will any other automotive brand (that I can find on google).
    Is that a K&N filter? If so, you've made a great point.
     
  18. cyclopathic

    cyclopathic Senior Member

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    So you agree that traction battery in Prii self-destructs after 30,000mi is proven fact, since you only have anecdotal experience with one (1) Prius disproving this?

    not sure but the oil is the same color hue. All cotton gauze filters have very similar performance levels, which is they don't filter as good as paper, but they don't clog.

    here is what K&N had to say about mass-flow failures, not sure if it classifies as "anecdotal" K&N Mass Air Flow Sensor Test Results
     
  19. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Mass Flow failures and reduced engine MTBFs notwithstanding...why put a K&N into a G3??? What is is that you're hoping to gain???

    I modified my V-Rod by opening the intake, then installing a high flow air filter (Amsoil Ea in my case) then uncorking my exhaust and then modifying my ECU. I'm not a mechanic by any means, but I don't think that the last step is necessary for a Prius, since I'm pretty sure that it has a closed loop FI.
    My result: About a 7-10 percent increase in RWHP, and a corresponding decrease in mileage...aggravated by my right wrist---no doubt! :D

    So...we come to the G3.
    What is the K&N supposed to be doing for you? If you say it's better for the ecology, then I would respect your warm wishes for our planet, and the added dirt that gets into your engine will probably not decrease your engine's service life by much. Usually cars go into bone yards from non-engine failures anyway.
    If you say that "more air is going to get into your cylinders" then I would submit that (1) you're still sucking air into the engine through the same itty-bitty straw that you're currently using---which is why K&Ns are usually mated with a modified air intake pipe, (2) If you haven’t made any corresponding exhaust modification---then you're still breathing out through the same restricted path that you were before, and (3) I'm thinking that the dizzy-wizz computer is going to keep your AFR about the same if you don't modify your mapping, regardless of your efforts to stuff more air into your motor.
    I could be wrong about that---I'll admit. I sling wires for a living.

    So what are we trying to do with the K&N on a Prius aynway?
    Save gas?
    How?
     
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  20. cwerdna

    cwerdna Senior Member

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    Thanks to cyclopathic for the rebuttals from K&N. Interesting... but still, not for me.