the cat on a vtr???

1. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

   #1 1st August 2006, 00:43

   i've been told that by taking out the cat on a vtr, it loses power(top end)? is this true?
2. YM03 Established Member Joined: May 2006 north east Posts: 1487 vtr mk2, posi blue

   #2 1st August 2006, 00:59

   are you on about fitting four branch or taking decating, as the face lift vtr has cat on manifold/downpipe, early vtr's are underneath, if done proply I don't think you lose top end, mine doesn't seem effected
3. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

   #3 1st August 2006, 01:04

   i've got the early type vtr, i've already changed the manifold to a 4-2-1, but i was told to keep the cat and not to get it decatted - is this true that it loses power?
4. YM03 Established Member Joined: May 2006 north east Posts: 1487 vtr mk2, posi blue

   #4 1st August 2006, 01:08

   it won't lose power, but I think it can drop some back pressure not sure tho.
   I've got mine decated and it makes a difference seems to pull so much better, and deffo not lost anything top end.
   
   if I was you I'd do it
5. R4T Saxperience Forum Bum Joined: Jul 2006 Posts: 4630

   #5 1st August 2006, 02:47

   i used to have a mark 1 vtr with a decatted exhaust and back box i notcied a suprising difference,as the man above said you do lose a little back pressure but it definately makes a difference go for it
6. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

   #6 1st August 2006, 23:34

   any1 else....
7. bennivtr Regular Poster Joined: Oct 2005 Lisburn United Kingdom (Northern Ireland) Posts: 319 Saxocup

   #7 1st August 2006, 23:41

   when mine was decated, de centre boxed, with a backbox i definately didnt lose top end!
8. DAZ1985 Frequent Poster Joined: Jan 2006 Stoke on Trent United Kingdom (England) Posts: 700

   #8 2nd August 2006, 17:36

   No you dont loose top end if its done right.
   
   I've lost top end through my gearbox but it gets their quicker.
9. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

   #9 2nd August 2006, 21:47

   Quote:

   Originally Posted by DAZ1985 No you dont loose top end if its done right. I've lost top end through my gearbox but it gets their quicker.

   could you tell us what you mean by done right?
   
   cheers
10. DevilDamo Saxperience Addict Joined: Sep 2003 Posts: 13761

    #10 3rd August 2006, 10:48

    I had the cat. removed. The car felt a lot more responsive. It improved in the torque at low range too (after taking it on a rolling road). There was however a slight problem with the fuelling but that was only because I had the lambda sensor dangling in mid air and not connected to a sleeve.
11. DAZ1985 Frequent Poster Joined: Jan 2006 Stoke on Trent United Kingdom (England) Posts: 700

    #11 3rd August 2006, 17:11

    Quote:

    Originally Posted by G187 could you tell us what you mean by done right? cheers

    
    Yes i could its just stating the obvious though really !!!!
    
    The right way round, make sure its in tight and sealed properly
    
    If thier is any more someone will add
12. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

    #12 3rd August 2006, 22:25

    why have gmc said this "...taking the CAT out and substituting a straight pipe will not be correct and so you will loose some power" - on their site they have explained it further more - this is the only thing from stopping me from getting decat pipe - this is the answer i thought one of you guys would point out
13. ets2k9 Saxperience Post Whore Joined: May 2006 Hednesford, West Mids Posts: 6230 Seat Leon Cupra R

    #13 3rd August 2006, 22:38

    Quote:

    why have gmc said this "...taking the CAT out and substituting a straight pipe will not be correct and so you will loose some power" - on their site they have explained it further more - this is the only thing from stopping me from getting decat pipe - this is the answer i thought one of you guys would point out

    Because there trying to sell you a £400 exhaust...............
    
    Maybe we should have a thread "The Truth about decat's" as I've read all these crazy things about decats which at the end of the day is just abit of pipe.
14. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

    #14 3rd August 2006, 22:49

    erm... i've spoke to other people about it is well and they've gave me the same reason why not to take it off
15. ets2k9 Saxperience Post Whore Joined: May 2006 Hednesford, West Mids Posts: 6230 Seat Leon Cupra R

    #15 3rd August 2006, 22:52

    Quote:

    erm... i've spoke to other people about it is well and they've gave me the same reason why not to take it off

    So your doing a survey then?
16. Mattvtr Saxperience Forum Bum Joined: Jan 2006 hinckley Posts: 2580

    #16 3rd August 2006, 23:16

    do you not need some sort of silencer etc to keep up the pressure?
17. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

    #17 3rd August 2006, 23:31

    Quote:

    Originally Posted by ets2k9 So your doing a survey then?

    no survey, just want to know more people's view's
18. G187 Frequent Poster Joined: Nov 2004 Hayes, Middlesex Posts: 758 MK1 VTR

    #18 3rd August 2006, 23:32

    Quote:

    Originally Posted by Mattvtr do you not need some sort of silencer etc to keep up the pressure?

    no idea mate
19. DAZ1985 Frequent Poster Joined: Jan 2006 Stoke on Trent United Kingdom (England) Posts: 700

    #19 4th August 2006, 12:03

    Quote:

    Originally Posted by Mattvtr do you not need some sort of silencer etc to keep up the pressure?

    
    Yes but surely that pressure would be retain by the middle box ???
    
    So in theory your back pressures would alter slightly as the wave has to travel further to get to the middle box than if they went to the cat
20. Mattvtr Saxperience Forum Bum Joined: Jan 2006 hinckley Posts: 2580

    #20 4th August 2006, 12:29

    yeh i agree with that,i was on about if you had a straight through system,should have made that clear
21. DAZ1985 Frequent Poster Joined: Jan 2006 Stoke on Trent United Kingdom (England) Posts: 700

    #21 4th August 2006, 12:35

    If you had a straight throught system then it would totally screw up the back pressure it would cause the car to run like a bag of shit.
    
    This is because its the back pressure which draws more exhaust gases from the engine.
22. Reef Saxperience Forum Bum Joined: Dec 2005 Birmingham Posts: 2524 Leon Cupra 20V 1.8T Lancer Evo III

    #22 4th August 2006, 12:43

    Quote:

    Originally Posted by DAZ1985 If you had a straight throught system then it would totally screw up the back pressure it would cause the car to run like a bag of shit. This is because its the back pressure which draws more exhaust gases from the engine.

    so ...... i'v got a straight through system on my mk2 saxo, no silencers, no thing, just manifold/cat-back all the way to back box.
    
    Does this mean, if i get a 4-2-1 my car would run like a bag of shit ?
23. DAZ1985 Frequent Poster Joined: Jan 2006 Stoke on Trent United Kingdom (England) Posts: 700

    #23 4th August 2006, 12:55

    Cat on the manifold im assuming ???
24. Reef Saxperience Forum Bum Joined: Dec 2005 Birmingham Posts: 2524 Leon Cupra 20V 1.8T Lancer Evo III

    #24 4th August 2006, 13:00

    Quote:

    Originally Posted by DAZ1985 Cat on the manifold im assuming ???

    yup cat on the manifold (what a stupid idea by citroen)
25. Billog_VTR Regular Poster Joined: Jul 2006 Teesside Posts: 470 Saxo VTR mk1

    #25 4th August 2006, 13:58

    mines a late mk1 with de-cat and 4-2-1 mainfold. Back pressure sometimes bit iffy but no top end is lost if done right.