ToDe-cat or not to De-cat that is the question?

  1. #1
    Need a direct answer.

    Got a supersprint mani and full magnex cat back system need to know what if any dif it will make de-catting this set up?

    and dont say use the search button done that and it varies so much it gets confusing so it is easy yes or know and a little of why.

    Pretty urgent as car booked in for tomorrow

    cheers
  2. #2
    Basically, Decatting with give you a few extra ponies mate and make it abit louder
  3. #3
    De-cat it....
    Reason; Cause you have to, simple
  4. #4
    Yeah get it done ...
  5. #5
    Decatting any car makes a difference.

    to be fair.....theres no reason not too except the fact its illegal obviously
  6. #6
    What about the loss of back pressure causing mid range torque to drop slightly?
  7. #7
    Quote:
    What about the loss of back pressure causing mid range torque to drop slightly?
    Get a BTB.
  8. #8
    the car with the decat should feel more responsive, defo worth doing

    btbs rock
  9. #9
    Quote:
    Originally Posted by Yates View Post
    btbs rock
    yours rocked the whole street
  10. #10
    definitely more responsive

    you should de-cat it even if it's just to try it, it's so easy to change
  11. #11
    whats a btb? lol
  12. #12
    not sure what it stands for

    http://www.btbexhausts.co.uk/
  13. #13
    back to best i was told, something along those lines

    it rocks my whole house, but the sound of it, mmmmmmm
  14. #14
    go for the de-cat, make sure you can interchange it for the MOT so you can put the cat in so it passes emissions
  15. #15
    probably get some mroe response out of it to, but other than that what the lads have already said bit more power bit more noise
  16. #16
    De-catting is illegal if the car is going to be used on road, as it will fail emissions. Also if you crash it, it is unlikely insurance will pay out as the car is not road-legal, so you'd be fucked.

    Its also a real pain in the arse swapping it over with the cat come MOT time.

    Not really worth it IMO for just a bit of noise and a few extra hp

    If you just want the extra noise I suggest a nice loud chavy exhaust and a sports cat for the popping/burbling.
  17. #17
    i thought instantly to btb... back to bed, mayby that should be me
  18. #18
    You could try a sports cat. The standard ones are about 400 cell, or similar. Try something that's 100-200 cell. Powerflow make sports cats... don't know how legal they are.
  19. #19
    im not certain but i didnt think it was law that you have got to have a cat as some cars dont need them to pass emisions tests?
  20. #20
    i say decat it, if you dont like it whack the cat back in
  21. #21
    Not worth De-catting.

    the power you receive, you can spend a little mor eand have a car that has a valid MOT and insurance certificate.

    Plus who's going to be pulled to one side?

    A quiet sleeper car or a saxo with a rocket sticking out the back roaring along?
  22. #22
    Well decided car getting de-cat fitted today and if it rubbish will take it of again and flog it only loss will be the fitting charge so no issue.
    Had a go in a vts last night that is de-catted and alot more responsive than mine and that made my mind up cheers gaz-vts for that.
    Will repor back once i pick the car up cheers for your help.
  23. #23
    Early reports suggest that i was right to de-cat the car. And not to much of a change in noise just has a little more rasp.

    Alot more responsive throught the rev range and has a little bit more kick in it.

    if anyone wants to know my set up is-

    supersprint manifold, custom de-cat, full magnex system cat back.
  24. #24
    You forgot to add 'MOT fail' to that list.
  25. #25
    That why it a custom de-cat interchangeable for ease when MOT due!
    Who cares until MOT due then will sort it so " AM I BOVERED"
  26. #26
    Good job man ...

    I notice better fuel economy with my de-cat as well ...
  27. #27
    I did not want to say anything incase i was seeing things but have noticed that i do get slightly more miles to the gallon than norm.
    Thought it was just me.
  28. #28
    some MOT places won't fail a decat if it still passes emissions.

    I decatted my VTR, it does make them feel a lot better more responsive but less pull from the off. When I changed mine for the mot I could definately feel the difference.
  29. #29
    i just stuck a de-cat on mine and wouldnt evan think of changing it back - only time wil be is when its due for an mot
  30. #30
    As a few have said, i wouldn't de-cat mine as i dont race it and id rarther stay legal. If your going to be wacking it round a track then fair play, do it. If not though, i really dont see the point..
  31. #31
    Dont really see what dif it makes really for all the time it takes to change it over.
    Have had many people say that it lacks in performance on there VTR but must say no lack of performance in the VTS if anything it has made a huge dif to the take off speed and my top end abillity, dif shots through the rev range more freely than before and alot more responsive and fun to drive.
    In all i would say that i dont mind the maybe 30 mins swaping it over for MOT time as it has def been a worthy purchase.
  32. #32
    So what do you do if police do a roadside emissions test?
  33. #33
    Dont drive like a fanny and you will never have to find out!!!
    Not been pulled by the police yet and as long as your exhaust not too loud which mine isn't and you not acting like a fud by answering them back you should be ok.
    90 percent of the time they just have a quick look over your car.
    But to put your mind at rest will have an emissions test done at ma mates garage tomorrow tell you what happens.
  34. #34
    Quote:
    Originally Posted by mottester.co.uk
    EMISSIONS WITHOUT CAT

    The MOT regulations say nothing about a vehicle having a catalytic converter. They merely set emission levels which have to be achieved ...
    Source: http://www.motester.co.uk/qanda.html

    The police dont regularly carry emissions test kits with them so its only VOSA checkpoints you would need to worry about, if you failed their emissions test they might fine you but probably just issue you a ticket to have your cat converter replaced and an MOT retest.

    As the cat converter is in different places on different cars, i.e. in the downpipe, under the car etc its dificult to tell if a car has a cat or not any way.

    If you have a horrendously loud exhaust you might draw more attention to yourself and force them to scrutinise the car further.

    Never realised some people have such bizarre views on decatting.
  35. #35
    Well had the car tested yesterday and passed its emisions test but only just and no more but hey it still passed.
    Was told that it depends on the car on the day when being tested, could prob fail today if re-tested but goes to show how close he paramiters really are with or without a CAT.