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4-2-1? 4-1? Extractors broken down!

Discussion in 'News and Features' started by Izso, Oct 24, 2011.

  1. drexchan

    drexchan Senior Member
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    Zeroed has got it exactly right about the size, scavenging effect and what 'back-pressure' is.

    ---------- Post added at 03:27 PM ---------- 6 hour anti-bump limit - Previous post was at 03:13 PM ----------

    V is volume. This is the Gas Law for for gas thermodynamics, not fluid dynamic.

    The correct relation is PV=nRT, with n being number of mol (1 mol = 6.02x10^22 particles).

    ---------- Post added at 03:36 PM ---------- 6 hour anti-bump limit - Previous post was at 03:27 PM ----------

    You started with using the wrong formula so.....

    Anyway, you don't want to cool it down because that will only increase the density, and denser gas has higher inertia like a heavier pulley is harder to spin. You want to keep it hot.

    Then there's a consideration on the piping size too as bigger pipe has larger external surface for heat dissipation. Like what Zeroed has pointed out on how the size affects velocity and scavenging, it affects the temperature (and then the density, then the pumping lost) too.
     
    #21 drexchan, Oct 25, 2011
    Last edited: Oct 25, 2011
  2. monsh

    monsh 5 Year | Silver

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    well, to my believe, there's a reason the engineer created the pipe path and also size they used for each engine .
    probably the best option u have for ur system .
    unless u go for performance engine or turbocharge ur engine, then its already a different story.

    i think there should be a follow up on this .
    probably the effect of s-flow, straight, twin exhaust .

    and also the effect of straight pipe, orignal path pipe .

    btw, after a few months of research, i think its best to stick to the original route + original pipe size.

    probably just change to 4-2-1 header,catcon, mid bullet,back bullet, straight muffler.

    well to me, i dont want to compensate the fuel consumption just for power. its not worth the modification then i believe .
     
  3. drexchan

    drexchan Senior Member
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    S-flow, straight flow, mid bullet, back bullet, mid box, back box, muffler, resonator.. arrggg.......

    I am going to have a long whine about these terms.
     
  4. monsh

    monsh 5 Year | Silver

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    these questions need deeper thoughts .

    and the terms used is almost similar .

    i think bullet/box/resonator is similar thing .
     
  5. drexchan

    drexchan Senior Member
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    And then there are league of people who concern about the placing or arrangement of the mufflers on the pipe. "-_-
     
  6. zec22

    zec22 Senior Member
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    Thanks Izso for the information. I'll source for a 4-1 from now on then.
     
  7. deliquent

    deliquent Senior Member
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    great article & example.... :congrats:
     
  8. monsh

    monsh 5 Year | Silver

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    yeap, thumbs up for the great article but then again, there's a lot of factor to the performance and its always the "lose some gain some" condition when u play around these things .
     
  9. kumbang

    kumbang Senior Member
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    nice write as always.

    Yup, wish theres more explaination on pipe size, bullets, s-flow n etc

    can i like mix the pipe size, ex : 1.6 till mid then smaller size?
     
  10. drexchan

    drexchan Senior Member
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    Piping and such should be discussed in another topic. I am working with izso to get a condensed and easy to understand article on it.
     
  11. biz-da-tech

    biz-da-tech Senior Member
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    ahh cant wait for the piping info... really interesting on that 1 i felt.
     
  12. kumbang

    kumbang Senior Member
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    me too, most post by izso :top:, all really informative.

    i'm a nub on car mods.
     
  13. LOPI

    LOPI Senior Member
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    Thanks bro for gud info..you really helping us to understand much better..go through detail..:)
    For those who confius this tread really help..
     
  14. Izso

    Izso Boooooossst
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    As I've mentioned a few times before, the real sifus are the ones in the background keeping quiet. I'm only sharing what I learnt from them. In this particular case it's Drexchan's extractor post, not mine! :biggrin: so kudos to the silent sifus
     
  15. csl

    csl Senior Member
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    How can the valve over lapping coverage missing in an exhaust related topic?
     
  16. Izso

    Izso Boooooossst
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    Erm.. this is an extractor topic, not exhaust topic. Not quite the same thing? Related but not related. LOL
     
  17. drexchan

    drexchan Senior Member
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    We are assuming the entire head assembly being untouched, with only the extractor replaced, and comparing both common types of extractor for a straight four. This is the most common thing beginners do.

    Advanced users will look into optimizing the performance (with the new extractor) by means of cam adjustment, air/fuel ratio and ignition timing. Some will go further with port & polish, valve angle cut, high compression, management, etc.

    However, whatever one do to a 4-2-1 can't make it performing like a 4-1, or vice-versa. Therefore the other tuning techniques are not discussed here.
     
  18. D7zul

    D7zul Senior Member
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    [​IMG]

    After calculating..

    the right extractor for me is a bigger 4-2-1 :biggrin:

    namely HKS extractor.. any1 here have this for sale??? :burnout:
     
  19. r3dster

    r3dster Senior Member
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    hmm..good read.
    but i've been reading around and yet still unable to get a concrete answer to it.
    if 4 - 1 provides power at higher rpm and 4-2-1 at lower...
    how about...equal lengths and unequal length headers? as such for example; scoobies have performance setup for both equal and unequal lengthed extractors....
    dispite the fact uneqal length gives you a much clear growling,but....if aftermarket high performance company makes both of them surely there's a difference in it's output...anyone has a concrete answer to this?

    Thanks a bunch
     
  20. Izso

    Izso Boooooossst
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    You're getting into specifics and that's more advanced than what Drex has explained. Have a read here and see if it answers your questions :

    Custom Extractor

    Apparently this guy got inspiration from someone in ZTH! Doesn't really talk about how he did the calculation though but is still a pretty good read.
     

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