Standerd Cat Modification? Cheap Option

1. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

   #1 4th March 2010, 18:18

   Anyone Thought About Machineing out the standerd manifold and then knocking, breaking or drilling out the ceramic plates on the cat?
   
   mite not be as great as a 4-2-1
   
   but its free?
2. user_15516 Saxperience Post Whore Joined: Apr 2007 Posts: 6640 Integra DC5R & VTS

   #2 4th March 2010, 18:20

   You could do. If it's the close coupled design (CAT in manifold), remove the CAT element and bash the insides out.
3. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

   #3 4th March 2010, 18:30

   Yer it is in the manifold,
   ill have a go at it saterday and let yous know how it goes
   want the thing backfireing on shifts so this should do the job lol
4. user_15516 Saxperience Post Whore Joined: Apr 2007 Posts: 6640 Integra DC5R & VTS

   #4 4th March 2010, 18:32

   Someone I know did it to his VTR - i'm afraid to say it didn't sound the least bit different haha. The empty CAT acts as a silencer, so it's not really going to be any louder etc.
5. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

   #5 4th March 2010, 18:36

   Well if i take the cat out and fit a backbox n leave the central silencer for back presure it should shurely be louder?
6. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

   #6 6th March 2010, 12:12

   Much more power and a deeper note
7. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

   #7 6th March 2010, 12:59

   how about, 4-2-1 manifold straight through centre section and a nice backbox?
8. Lewis Saxperience Forum Bum Joined: Oct 2009 Middlesbrough/Coventry Posts: 3808 Megane 225

   #8 6th March 2010, 13:10

   Quote:

   Originally Posted by Sparco_Tom how about, 4-2-1 manifold straight through centre section and a nice backbox?

   That costs money, which he doesnt have. Id say give it a go mate and report back!
9. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

   #9 6th March 2010, 13:12

   well it is a waste of a cat, time and effort
   i have straight through centre sections for £35. manifold £80 then a backbox of some sort.
   Thats the money of a new cat come mot time anyways. Might aswell save the cat
10. VTRelite Saxperience Forum Bum Joined: Dec 2008 Gloucester Posts: 3000 Citroen Saxo VTR Renault 5

    #10 6th March 2010, 21:49

    Bashing the insides of a cat converter out is really a waste of time.
    
    Let me expain. When the exhaust gases exit the engine and go through a cat they will go through the cat more or less in a straight line. Taking the insides out creates,in effect, a swirl chamber and the gases are not passed straight through the hollow cat and just swirl around losing you power. A decat pipe, as the name suggests, is a length of straightish pipe which is the same bore as the rest of the system so the gases pass through nice and cleanly and in a straight line and will more often than that release 1-2bhp.
    
    So to summarise, apologies about the essay, SAVE UP FOR A DECENT SYSTEM AND FOR GODSSAKE DO NOT REMOVE THE INSIDES OF YOUR CAT AS IT WILL DO NOTHING
    
    Thanks for reading (if you did)
11. Cammy Established Member Joined: Jul 2009 Aberdeen Posts: 2211

    #11 6th March 2010, 23:23

    My old ZX6-r used to backfire on shifting up was fucking awesome lol
    
    full power and quick shifting up the gear and bang lol would like my car to do it but won't happen lol
12. user_39821 Saxperience Forum Bum Joined: Dec 2009 Uckfield, East Sussex Posts: 3362 Citroen saxo 1.4 furio

    #12 6th March 2010, 23:27

    The empty cat will help more than a decat from the original manifold. i wont go into it but i think there is an explanation on gmc motorsport's website
13. webby Established Member Joined: Jul 2007 manchester Posts: 2456

    #13 6th March 2010, 23:29

    that is for pulse length tuning not smacking the shit out your existing cat in the manifold.
14. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #14 6th March 2010, 23:30

    Quote:

    Originally Posted by C18VTR My old ZX6-r used to backfire on shifting up was fucking awesome lol full power and quick shifting up the gear and bang lol would like my car to do it but won't happen lol

    a healthy vts will do it with the right breathing mods. I miss it sooo much now.
15. Cammy Established Member Joined: Jul 2009 Aberdeen Posts: 2211

    #15 6th March 2010, 23:39

    Quote:

    Originally Posted by Sparco_Tom a healthy vts will do it with the right breathing mods. I miss it sooo much now.

    
    Get another hehe
    
    miss my bike shouldn't have sold it when I got another car :/ if I had another Choice of car or a bike, I know what would give me most thrills
16. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #16 6th March 2010, 23:48

    they are not cost effective
17. user_32315 Saxperience Post Whore Joined: Mar 2009 Uppingham, Rutland Posts: 9569 mk1 JP4'd VTR, '16 Fabia Monte Carlo

    #17 7th March 2010, 00:18

    you could just buy a standard mk1 manifold, that will de-cat your car and you will still have the cat for the mot, also im sure you could buy one for like £20
18. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #18 7th March 2010, 00:19

    ive been offered them for £12 delivered
19. Tom5190 Saxperience Post Whore Joined: Sep 2007 Someones Bumhole Posts: 5721 Mk2 16v Desire

    #19 7th March 2010, 00:24

    just no, as said above pointless waste of time and will most likely result in a loss of power not gain
20. EwynSaxo Established Member Joined: Dec 2008 Penpedairheol/Cascade/Bargoed Posts: 2104 Furio R.I.P, onyx Gti, astra turbo

    #20 7th March 2010, 00:39

    i did this
    doesnt sound decat but is alot louder
    and much quicker through the gears
21. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #21 7th March 2010, 00:40

    in your head?
22. EwynSaxo Established Member Joined: Dec 2008 Penpedairheol/Cascade/Bargoed Posts: 2104 Furio R.I.P, onyx Gti, astra turbo

    #22 7th March 2010, 00:44

    nah mate in real life
    before hand i couldnt keep up with my mates ZR at all
    now i stick with him unless we go over 100mph he pulls away then
23. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #23 7th March 2010, 00:46

    whatever mate
24. EwynSaxo Established Member Joined: Dec 2008 Penpedairheol/Cascade/Bargoed Posts: 2104 Furio R.I.P, onyx Gti, astra turbo

    #24 7th March 2010, 00:48

    well mate i dont need to lie
    was just saying to help who ever started this thread make their mind up on doing this or not
25. Tom5190 Saxperience Post Whore Joined: Sep 2007 Someones Bumhole Posts: 5721 Mk2 16v Desire

    #25 7th March 2010, 00:53

    there is no way that 'bashing out' your cat will give more performance, if it did why would specialist companies such as piper make manifould that are £300+. Basically an exhaust system is specifically designed around bore/length/shape to give the best amount of back pressure to help remove the exhaust gas's, bashing out the cat changes only one of these things which will unbalance the design resulting in WORSE pressure and a poor flow of gas.
    
    The only cheap way to decat a Mk2 properlly is to fit a Mk1 vtr manifold + downpipe however this still wont give any performance gains just a louder noise
26. LSOfreak Saxperience Addict Joined: Jan 2008 west london Posts: 13810

    #26 7th March 2010, 00:53

    think you'd be better off selling the cat instead of bashing the insides out. aren't the insides poisonous aswell?
27. Cammy Established Member Joined: Jul 2009 Aberdeen Posts: 2211

    #27 7th March 2010, 01:14

    It's not really free though is it, best buying a second hand manifold and fitting it yourself as your taking it off anyways, probly need a new mani gasket, bolts, gearbox bolt, and gasket which is roughly 18-19 £
28. gsavill90 Established Member Joined: Mar 2008 Skipton/Loughborough Posts: 1959 VW Bora TDI

    #28 7th March 2010, 08:55

    Quote:

    Originally Posted by jeffchiz you could just buy a standard mk1 manifold, that will de-cat your car and you will still have the cat for the mot, also im sure you could buy one for like £20

    This is your best option tbh.
    You don't want to ruin the cat, because come MOT time you'll have to fork out around 80 qud fr a new cat
    Should be able to get a mk1 manifold pretty cheap, and should make it sound a bit louder
    I was planning on putting one on my vtr... But a farmer took it for scrap metal
29. fdrightup Infrequent Poster Joined: Feb 2010 Posts: 125

    #29 7th March 2010, 13:14

    Quote:

    Originally Posted by Sparco_Tom how about, 4-2-1 manifold straight through centre section and a nice backbox?

    these can be found cheap depends where you look, can you weld
30. Sparco_Tom Saxperience Addict Joined: Jan 2007 Aylesbury, Bucks Posts: 12836 Yeaaahh Fiesta

    #30 7th March 2010, 13:41

    yer i can
31. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

    #31 7th March 2010, 19:16

    Knocked the cat out the otherday, getting the backfire i was looking for n never cost me nothing so...
    
    you get a nice whineing sound out it on tick over too so id say if you dont have money at the time and looking to get the thing popin and banging go for it
32. user_28147 Newbie Joined: Oct 2008 Perth Posts: 17 Saxo 1.1 2002 Saxo 1.6 2003 Clio Mk2 1.4 Sport

    #32 7th March 2010, 19:20

    and yes i can weld,
    
    and when you say you can get so n so for £300+
    im not looking for getting the ultimate 1.1 lolz
    was just looking to find out if i could get it backfireing more and i can