Welded catalyst or flanges?

[Faisal]

Hello,

i have had a sports cat installed a long way back by RMS in prestwick (i have heard mixed reviews from them ever since).

i do have one issue, they used a flange for the sports cat, and recently my exhaust sounded burst, it turned out that it needed repasted. had to travel all the way down to get that done. it worked, car was fine for a good while, but now im getting the same sound as i had before, and puffs of blue smoke on start up.

basically i need to go again (this is very impractical for me).

i asked them why they don't just weld it on and they said that it means the whole exhaust has to come off if there are any issues with the cat, which is why they use flanges.

the question is, should i go back and just get it repaste again?or should i pester them into welding it so it doesnt arise a 3rd time? is there any major drawbacks from having it welded?

 

[Willie]

Its up to you what is best, its your car not theres.
I'd get it welded and forget about it.
They don't seem to have much hope of there CAT lasting long

 

[Fl@pper]

they are putting paste on a flange in front of a cat ? hope not

personally i would ask them for one with a flat flange so you can bolt it up properly

 

[Faisal]

they are putting paste on a flange in front of a cat ? hope not

personally i would ask them for one with a flat flange so you can bolt it up properly

if its in front, is that a problem?what does that incur?

 

[Fl@pper]

well exhaust paste is designed to harden like concrete once it gets to a temperature and if it's spread too thick when put together it will just sit in the front of the cell of the cat and block it up (well part of it)

never use paste in front of a cat and i prefer using rtv silicone anyway, paste is jank if you have to re-assemble anything later

have a look under it yourself when you go back to decide on welding as that would be the best seal/solution but you need to consider removal access (to cut it off) should you need to and also why it keeps blowing anyway ?

either the surfaces are not flat and sealing properly or vibration is causing them to open up

 

[Fl@pper]

for example just think how free-flowing this would be if it had gobs of concrete play-do spread all over the front of it ?

 

[adm013]

Could you not get some kind of gasket made........plus how do other makers get away with it?

Andy

 

[Fl@pper]

metal gasket sometimes a metal cone ring type design, all depends on who/how it's designed to be honest

 

[adm013]

metal gasket sometimes a metal cone ring type design, all depends on who/how it's designed to be honest

Gimme a half hour in my shed..........