General Removing catalytic converter

[MIKO]

Will i gain any power? if i remove the catalytic convertor on my sei year 2000 model, spi,also will noise increase?and will the car work fine?THANKS

 

[Brooky]

Car will still work fine, slight noise increase and more chance of a backfire:slayer: :slayer: :slayer: :slayer: :slayer: obviousily a good thing

 

[MIKO]

Just That?

 

[beau]

i think they de-crease power low down in the rev range and increase it high up in the rev range.

 

[Brooky]

Just That?

Dont know really,i got a CSC mani and de-cat fitted at the same time so carnt comment on each one seperatly

 

[allanhelen]

I have a cat that i used to swap in at MOT time (until i forgot last year and it passed without the cat) anyway TBO there isn't a huge difference in performance. don't expect it to turn into a GTI overnight. There are lots of other mods that give more gains for less effort.

edit

also barely any difference in noise on my CSC cat back, maybe a bit raspier if anything.

 

[Diwiak]

sorry for a bit old topic

I think catcon is blocking a lot of gas running out, also good for sound,

2allanhelen: could you please tell me how did your remove that catcon??? Iam planning to do it this weekend, but dont have an idea what to use as a spare for catcon???? how did you stick it together??? because catcon is a one piece with front exhaust pipe, isnt it???or you just remove catcon inset from inside???

and dont u have an idea for home-modding rear silencer??? (for now, i have only new 77mm tailpipe)

thanks for advice, sorry for revival of old topics

 

[allanhelen]

I use a supersprint manifold so i have a custom cat section so it is flanged at the front and sleaved at the back

 

[fingers99]

Somewhere (maybe in his gallery) is a picture of Arc's mock cat.

But I'm told that the penalty for removing a cat in Slovakia is 2 years imprisonment in a cell shared by Borek and Igor, two gay former ice hockey players.........

 

[levemircento]

and dont u have an idea for home-modding rear silencer??? (for now, i have only new 77mm tailpipe

I have one, done it loads of times on loads of cars.

Ideally, your back box needs to be solid, good enough to weld to.

Drill a 20mm hole on the top of the silencer with a hole cutter [can do it anywhere you want] then inside you will see the strands of fibre, pick one out, pull it - it will keep coming out for ages, and you will end up with a big heap of it, cut a small piece of metal to cover the hole, and weld it on.

On my standard cinq sporting back box, the sound isnt noisy, but people often comment thinking I have sports back box.

If you do this to an actual sports back box, will will usually be of a straight through design, the sound will be very throaty and raspy, much like an old rally mk2 escort [sound wise]

if you decide its too noisy, grind off the patch, shove some of the fibre back in, re weld. Or simply just drill another hole to insert it back in through.

Sounds daft, but you really would need to try it to see and hear the difference. !

 

[Diwiak]

Somewhere (maybe in his gallery) is a picture of Arc's mock cat.

But I'm told that the penalty for removing a cat in Slovakia is 2 years imprisonment in a cell shared by Borek and Igor, two gay former ice hockey players.........

funny - where are u from, that u know slovak laws so well ???

probably cops won't look under the car, maybe guy at MOT will, but it's a bro's friend so hopefully i'll go only for week or two imprisonment

will try to "tune" that back box soon-so when i'll remove all that "useless" stuff from inside, it won't be too much noisy??? (I dont want it too noisy)-its original sporting back box

thanks

 

[levemircento]

it wont be too noisy if its the standard one

if the inlet pipe enters the silencer off centre, then do the mod on the end of the silencer that has the pipe in the centre, err - I will be back soon with a diagram..

 

[Diwiak]

it wont be too noisy if its the standard one

if the inlet pipe enters the silencer off centre, then do the mod on the end of the silencer that has the pipe in the centre, err - I will be back soon with a diagram..

so, u got it?? iam really horny for my "new" exhaust...

 

[levemircento]

so, u got it?? iam really horny for my "new" exhaust...

yeah

silencer A you can see its inlet and tailpipe are offset, you need to cut your hole at the part [red dot] that has the pipe in the centre, as this will be the section inside that has the fibre in

silencer B is a straight through type, cut your hole slightly off centre, if there is no fibre present then you may have a section at each end with it in, in which case cut where the green dot is

 

[Diwiak]

yeah

silencer A you can see its inlet and tailpipe are offset, you need to cut your hole at the part [red dot] that has the pipe in the centre, as this will be the section inside that has the fibre in

silencer B is a straight through type, cut your hole slightly off centre, if there is no fibre present then you may have a section at each end with it in, in which case cut where the green dot is

View attachment 41100

GREAT thanks very much!!!

 

[Diwiak]

what a dirty job... and you are removing fibre only from top part of backbox or all fibre from whole backbox?????
because i had already small rusted hole in the bottom in centre, so cut it bigger and remove some fibre out-theres still big hole so I dont know how it will sound like at this time because sound now is like... like leaky exhaust
its that backbox with inlet pipe offset(type A)

 

[levemircento]

If the silencer has done any sort of miles it will be dirty job, mine was brand new when I did mine.

If the silencer is rusty then you arent going to be able to weld up the hole you have made, as the welder might just burn holes instead of make a nice weld.

Once you start pulling the fibre, it should all come out, as its usually put in there as one long thread. if its the offset silencer, then ony one end if it will have the fibre in.

If it sounds like its blowing, then it probably is, here in the uk a brand new back box for a sporting is only about £22 from a factor, this mod isnt going to make it LOUD, just a nice burble.

EDIT: You say the hole is still there, in which case, it will sound like its blowing as it is!! BIG HOLE IN EXHAUST!! Get a patch welded over it, it will be ok.

 

[arseofbox]

Its a restriction in the gaspath so yes there'll be a gain there.

I cant see it being much gain - as its a fairly well designed restriction as restrictions to flow go -but its a PITA for MOT and that kinda thing

 

[levemircento]

Its a restriction in the gaspath so yes there'll be a gain there.

I cant see it being much gain - as its a fairly well designed restriction as restrictions to flow go -but its a PITA for MOT and that kinda thing

You talking about the CAT there? I assume so.

A neighbour of mine is an MOT inspector, cars going in the station where he works will not pass an MOT if the cat has been removed, the whole emmisions system is designed for it to be fitted, this is just an instance at his particular station, other places may not be that bothered.

 

[Diwiak]

there will be cat going out as well so dont worry about mot and all that useless things,

ehm theres a rusted plate but only in centre of bottom, so it will need big patch, and friend of mine is very good welder and he is master of what is he doing so it will be fine, will post picture later with video as well