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Thread: Turbo exhaust note (stock)

  
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    Turbo exhaust note (stock)

    All,

    I have often heard how the stock exhaust on the turbo lacks a note. Well, on my turbo, it usually is fairly quiet. Except, if I give it a bit of welly at 1800-2000rpm, especially in 2nd or 3rd, there is a fairly loud note (almost sounds a bit like a fart at times coming from the front of the car), that is there as the revs pick upto about 2500 (by which point the turbo is fully spooled), and then disappears (or gets quieter) again. Is this normal?

    Also, on the turbine side of the turbo, there is a grey cable running from it. Is this some kind of sensor detecting exhaust pressure?

    Jonathan

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    Where does this grey cable run to Jon? - I'm not sure i have seen it on my car :?: :?:

    As for the noise - the turbo's are generally very muted - due to the vast number of restrictions built into the exhaust system. Not sure about your farting sound but other than that nothing in your description seems out of order.
    Me run tings.... not tings run me!

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    T-bone

    Perhaps fart is the wrong word. Its just normally the exhaust is so quiet, and yet under this higher load, low revs, it becomes much more obvious, deep low pitch, and grumbly (better description than fart!)

    As for teh grey cable. It comes out from a thin cannister embedded into the side of the exhaust part of the turbo, a bit lower down from the wastegate arm. It then runs to somewhere higher and to the right of the engine where there is an electrical connection. I can take a picture and post it later!

    Jonathan

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    The grey cable is probably the 02 sensor.

    The exhausts are so restrictive on these cars the exhaust does sound farty as some revs.

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    farty ? what do you mean... i get a gwaaaaaaaaaaaaaaaa noise at 2500 rpm if held there.... from front?

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    The exhaust note is only under load, low revs and accelerating. If I hold at 2500 rpm my car is dead quiet. If I am doing motorway speeds and put my foot down (which is around 3000 revs, its still very quiet).

    The fart sound..well imagine a deep buzzing sound overlayed with what sounds like air stuck inside a pipe desperately trying to get out (e.g towards a fart). i.e the word restrictive that Matt said is how it sounds!

    Jonathan

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    This is norma, Jon - as ever if it still pulls well you don't have a problem. The turbo's are v.quiet as standard
    Me run tings.... not tings run me!

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    Hi T-bone. Thanks and don't worry, I am not noise paranoid

    The turbo is v.quiet normally, unless I floor it in the lower gears, in which for a car with this power, its quiet, but compared to my 2.0 (non turbo) I had before, its noisy...but in a good way The turbo has more of a snarl to its sound, especially after 4500rpm.

    The reason I first inquired about this, is because around 2000 revs, it also takes around 2 seconds for the turbo to really spool up to maximum pull (by which time you are doing 2500 revs). The louder exhaust note seems to correspond to the time where the car is really working hard trying to accelerate and get that turbo spooling at the same time.

    Jonathan

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    re: Turbo exhaust note (stock)

    Here is the grey wire I was talking about. Apologies it was a camera phone....

    www.statt.org/greywire.jpg

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    Quote Originally Posted by jonstatt
    T-bone

    Perhaps fart is the wrong word. Its just normally the exhaust is so quiet, and yet under this higher load, low revs, it becomes much more obvious, deep low pitch, and grumbly (better description than fart!)

    As for teh grey cable. It comes out from a thin cannister embedded into the side of the exhaust part of the turbo, a bit lower down from the wastegate arm. It then runs to somewhere higher and to the right of the engine where there is an electrical connection. I can take a picture and post it later!

    Jonathan
    John are you refering to the O2 sensor that is usually plugged into the pre cat of the car?? You have two sensors one on the precat (or dump pipe ) in my case and the other on the cat itself.

    Have you changed your back box? it could just be the way that your back box is designed, i have a xforce muffler on my turbo and its too loud, i hate it, going to have to put another muffler to make it bit quiter.

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