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Thread: 1.7 dti decat. is it worth it?

  
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    gazvan_86's Avatar
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    1.7 dti decat. is it worth it?

    hey people.
    just wondering if removing the cat on the 1.7 dti lumps is good or bad for these engines and wud there be any power gains? i know that certian engine work better with and some work better with out.
    has anyone done this and noticed and gain or drop in performance?
    also if you have had it done and kept it as a decat is there any emmision problems at mot time?
    cheers for any help
    streetbasser

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    Fabyoulous's Avatar
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    Emissions isnt an issue on diesels, just smoke you have to worry about at MOT time. Cant see that a cat would reduce smoke that much.

    Should make a slight increase in proformance, should also be able to hear turbo more.

    Apprently it could damage the turbo as theres less back pressure, not sure how true that is though.

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    jiberson's Avatar
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    You do risk premature turbo failure from a decat as it allows the turbo to run over speed due to a lack in back pressure. Performance gains would probably be noticeable tho.

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    gazvan_86's Avatar
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    humm, tempted to but the tubo failure dont sound to good lol. i could decat it but on a join in the exhaust system i cud try different size restricters.with abit of trial and hopefuly no error i can find a happy medium.
    may have to look deeper into this.
    cheers guys
    streetbasser

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    i have a 1.7dti 8valve astravan with turbo back exhaust, cat and silencer gone, 2'' straight thru to a nice back box. not noticed alot of power but has improved it.

    my mate has the sportif which is 16v model and that goes far better with the same sort of exhaust.

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    TPTuning.co.uk's Avatar
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    it wont give you much power gain on a diesel what it does do is make the engine rev better and free er.

    as for the turbo issue my mate is running a straight through standard size tho and has covered about 10k with no problems thats a 1.9 cdti 200bhp tho

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    H477150N's Avatar
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    i did this yesterday to my 1.7cdti and does feel alot smoother revs wise and sounds pretty nice too

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    Billy Dean's Avatar
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    Isn't this 'mod' one of those where you will only notice the full damage to the engine/turbo after doing some considerable mileage, e.g. 20k or more?
    Is it really worth finding out if it is damaging by testing it yourself on your own car?


    A bit like people not knowing smoking was hazardous until cancer started kicking in after a generation...?

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    jimdt's Avatar
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    hmm i was tempted to do this when cut out the centre silencer,chance of turbo failure puts me off although its done 100k so i wouldnt be suprised if it went soon

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    G8RDK's Avatar
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    i have a decat and full stainless system on my 1.7 dti van made a good improvement, the turbo seems to come in harder and the van breathes a lot better, i have also fitted a k&n panel filter and derestricted the air box, the next thing im looking at is having the injectors cleaned and remapped maybe a bigger intercooler

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