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Thread: middle box?

  
  1. #1
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    hindyastra's Avatar
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    middle box?

    hi all,

    i have just bought a 6x4oval exhaust of a lad on here and fancy puttin new middle box and centre section, i dont know to much about these but i am aware that the remus racing tube is to loud, i dont want anything loud at all, just a bhp increase would be nice.

    what you all recommend?

    some vids of the sound would be nice?

    cheers hindy

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    Toms1989's Avatar
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    Well if you want a power increase / throttle response, ditch the mid silencer is your best bet!

    they don't sound too loud at all with the centre section removed

    Here is my Piper RS 3.5" backbox with a remus style centre section

    http://uk.youtube.com/watch?v=es85gW...e=channel_page
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    Quote Originally Posted by Toms1989 View Post
    Well if you want a power increase / throttle response, ditch the mid silencer is your best bet!
    Not so. You do that if you want more noise.

    Replacing the OE centre section for a 'straight through' one will do what you say... and contrary to popular belief that can mean a silenced or unsilenced centre section.

    Normal silencers are 'baffled' which means the gas takes a contorted path through the silencer, which causes it to loose (sound) energy on the way, as well as causing a restriction to gas flow.

    A straight through one uses sound absorbing packing, to reduce noise levels without impeding gas flow. like this...



    I can't think of one decent aftermarket exhaust manufacturer that doesn't use straight through silencers

    In fact, as the silencer will get and stay hotter than a similar length of plain pipe, it's actually keeping the exhaust gas hotter which maintain velocity in the pipe, which helps power levels.

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    Hmm...replacing the centre silencer with a straight through pipe will increase noise...if you want a performance increase without much more noise then look for a straight through pipe with a centre silencer. I'll admit to never seeing them on their own, most are with backboxes, but maybe an e-mail to Cybox via eBay would be worthwhile, they may make you a centre silencer on its own, as they will make them if you get a full catback system (which they did for me).

  5. #5
    fdrightup
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    Quote Originally Posted by Ffoeg View Post
    Not so. You do that if you want more noise.

    Replacing the OE centre section for a 'straight through' one will do what you say... and contrary to popular belief that can mean a silenced or unsilenced centre section.

    Normal silencers are 'baffled' which means the gas takes a contorted path through the silencer, which causes it to loose (sound) energy on the way, as well as causing a restriction to gas flow.

    A straight through one uses sound absorbing packing, to reduce noise levels without impeding gas flow. like this...



    I can't think of one decent aftermarket exhaust manufacturer that doesn't use straight through silencers

    In fact, as the silencer will get and stay hotter than a similar length of plain pipe, it's actually keeping the exhaust gas hotter which maintain velocity in the pipe, which helps power levels.
    +1 straight though type design is best for the centre box on my astra i used a vw jetta gti centre box baffle inside diameter 55 mm

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    All down to preference really

    I think its done my car better ditching the centre silencer
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    of course your car will be better... you've ditched the restrictive OE centre section and got a free flowing one

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    There'll be negligible power difference between a silenced and non-silenced straight through centre pipe. The main difference is purely down to noise levels. Loud does not equate with power.

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    Quote Originally Posted by nry View Post
    There'll be negligible power difference between a silenced and non-silenced straight through centre pipe. The main difference is purely down to noise levels. Loud does not equate with power.
    No I know, Nor was I implying it

    I removed it to improve throttle response

    Principal is the same as a weapon silencer, perforated baffle internals, you do gain the odd few fps, but at the same time you get a lot of noise
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    I removed my centre box on my mk5 and just had a straight through pipe. I had better throttle response at higher revs, but the lower end was rubbish due to lack of back pressure. also, at motorway cruising speed, the noise was deafening! really not nice with a headache. Ime looking into putting a cherry bomb centre in just to lower the noise, but give it that deeper growl.

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