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Thread: De cats

  
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    Astra_Craig's Avatar
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    De cats

    iv got a 1.6 8v with a sportex exhaust system, centre racing pipe and i was wondering if i get a de cat will it make it quicker and louder

    also where can i purchase a de cat pipe

    thanks

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    ZS's Avatar
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    A decat will make it louder, but to be honest every 1.6 8v I've heard with a big exhaust has sounded miserable. Like a Saxo that's ram-raided Halfords, you know the type.

    Which 1.6 8v do you have? Is it the pre-2001 X16SZR or the post-2001 Z16SE? The Z16SE will be next to impossible to decat due to the cat being integrated into the manafold, and the fact the ECU relies on lambda sensors each side of the cat to control the emissions. You'd be looking at a custom manafold and custom engine management, which is a little pointless on a rubbish engine like the Z16SE.
    2007 Metro Blue 5 door Mk5 Elite 1.7CDTI
    6th Vauxhall (4th Astra) in 10 years...plus a couple of other sheds...

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    Best off leaving it as it is IMO - the straight thru section & sportex should be fairly loud as it is so any additional de-restriction may make it louder

    BUT

    good luck if u get stopped!

    The cat is there for a reason and is a legal requirement. If u get pulled then ur buggered basically.

    What exactly do u want to achieve?
    An ever so slight increase in performance or a overly loud exhaust tone which only draws unwanted attention?

    Trust me....you're probably on the limits already of what this engine can achieve (Ive got the same engine too - not for long!)
    Once youve sorted the induction and exhaust side of things then you're almost done.
    Without spending big bucks u wont get much more out of the motor.

    So to sum it up.....removing the cat may make things louder and slightly improve performance but the pay off being the car is now illegal.

    What year is ur car anyway? early 8v models X16SZR have the cat on the front pipe so a decat would mean chopping the front pipe - removing the cat - and welding in a straight piece of pipe....
    The later models (2000 onwards) Z16SE have the cat built into the manifold itself so youd have to do a little more legwork in removing this....a mani from an earlier car may be adapted to fit...but IMHO its all a pure waste of time n money for what could eventually end up with a nice healthy fine!

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    mines a 99 and the cat is separate to the manifold

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    well in that case feel free to chop the front pipe and weld in a straight piece of pipe but dont say we didnt warn ya come MOT time or when the plod catch ya! lol

    Good luck!

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    I got my local powerflow to chop mine out and replace it for a straight piece on my C16XE corsa GSi...not much difference in performance but it was noticably louder
    X20XEV Gsi Now sold but now have a Corsa GSi C20XE

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    Quote Originally Posted by sam_p2000 View Post
    I got my local powerflow to chop mine out and replace it for a straight piece on my C16XE corsa GSi...not much difference in performance but it was noticably louder
    this is why I wouldnt recommend it..... no increase in performance - just an increase in noise...just enough to attract unwanted attention from the plod.... now that would be interesting when they discover the reason ur car is so loud!

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    Yeah that and i dont know if it was the cause but my valve lifters went soon after and it used to backfire like nobodys business on the overun! lol
    X20XEV Gsi Now sold but now have a Corsa GSi C20XE

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    sam witch powerflow was this as i got told that they were not allowed to de-cat the car due to it being a mot failure
    astra coupe bertone on 18" pro race 1.2s now on coilovers

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    Basingstoke one its a Topgear franchise. They wanted about a ton for a drop in drop out one or 60 notes to do a permenant welded swap. I wouldnt do it again to be honest...only if i had a turbo or something that would benefit from a loss of that much backpressure.
    X20XEV Gsi Now sold but now have a Corsa GSi C20XE

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