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de cat question

Discussion in 'A3/S3 Forum (8L Chassis)' started by s3gazz, Jan 12, 2011.

  1. s3gazz
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    s3gazz Active Member

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    hi all
    having my s3 de catted today can anyone tell me the differances ill notice or ill get from it please tar
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  2. DaveA3
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    DaveA3 Audi A-Trizzle!

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    faster spooling an increased sound and low end torque
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  3. s3gazz
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    s3gazz Active Member

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    tar dave its on a standed exhaugst tho will i still notice all that mate
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  4. dany2k
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    dany2k Member

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    the cat restricts exhaust gas flow, so no matter if you've got a standard or otherwise, u'll notice the above. i dont have the balls to do it myself, good on ya.
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  5. DaveA3
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    DaveA3 Audi A-Trizzle!

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    yeh should do mate. u getting a larger downpipe also? that will do the above to a further extent
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  6. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    When i put my downpipe and decat the turbo spool was noticably quicker and pulls harder but you probably will lose some end end torque due to the increased diameter and less back pressure.
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  7. s3dave
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    s3dave TFSI Hybrid

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    A Turbo should not need back pressure, maybe a slight bit
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  8. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    Ye too much back pressure on a turbo engine is not good as with pressure you tend to get heat which as everyones probaby aware is the enermy as such on turbos but some back pressure can help with the torque.

    Having a more freer exhaust will help get the exhuast gases out and the quicker you can get it out the quicker you can get it in but likely to lose a bit a torque due to the less back pressure. Thats how i understand it, correct it if its wrong lol.
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  9. s3dave
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    s3dave TFSI Hybrid

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    The turbo itself creates back pressure so as little as possible after that
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  10. Welly
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    Welly VX220 SC Driver :)

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    Is it a decat, or a downpipe and decat?
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  11. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    True far point dave.
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  12. s3gazz
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    s3gazz Active Member

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    just a de cat welly iv notice a dif already spoll wize but car not running good anyway so wont no till its fixed
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  13. superkarl
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    superkarl MAN OF STEEL

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    Does it have a hole for the post cat lambda? ThAts what I'm worried about
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  14. s3gazz
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    s3gazz Active Member

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    ye it does mate in need of down pipe now an cat back
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  15. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    The post lambda is useless if you have a decat though as its only there to monitor the condition of the cat, but you wont have one lol.
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  16. superkarl
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    superkarl MAN OF STEEL

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    So you could just disconnect it? Which would probably bring the engine light on
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  17. S3 Nattie
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    S3 Nattie Quattro ist für sissies

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    Ye, its useless. When I put my downpipe and de cat on I couldn't get the lambda sensor out of the original cats (welded on) so didnt even have the sensor on my car for a few days till I got the sensor out.

    You will always have a fault code till its mapped out when you get your car mapped but it doesnt effect the way the car runs. I had a EML on at first but once I deleted it, the light hasnt come on but the code still there.
    #17
  18. s3gazz
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    s3gazz Active Member

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    i just bought one few days ago gutted wish i could take it back lol its the other one i needed
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