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Discussion Starter #1
Ok as the title says which do you think is better my cat started breaking down and i was wondering if its better to cut it out and use straight pipes or should i drop the cat and gut out inside of the cat. I know that the backpressure of a gutted cat is suppose to be better than just having straight pipes.
any help would be nice thanks.
 

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Yardie, my recommendation would be to just gut the catalytic converter however I am unsure of what your emission laws are in Jamaica.

The use of just a straight through pipe will result in an increase in sound and the note will be more unpleasant, more raspy if that is a term to explain such a noise over there:thumbsup
 

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Yardie have you changed your vehicle since joining as it says in your car specification box that you have a 1994 E36 320 coupe:thumbsup

Just need to check the details to retitle this thread correctly;)
 

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Discussion Starter #4
no emission laws or sound laws here in jamaica but its not the sound i want to go for i want which ever better cause i realize when like active makes there test pipe it still has like a pan there and i think its realted to the back pressure in the exhaust.
 

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Discussion Starter #5
it was originally a 320 as far as paperwork. I have since put in a m50 325 vanos engine full m3 suspension , driveline and brakes and some other little stuff. So ye it is a 325 motor that we are talking about
thanks
 

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The insides of a catalytic converter restrict the flow. The exhaust gasses have to pass through a ceramic honeycomb which really restricts the exit:thumbsup
 

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Discussion Starter #9
Ye i get what your saying about the inside of the cat but what im trying to find out is if i drop the cat and get out all the honey comb and other stuff in there will it be better i do that or just put in the str8 pipes ?? de gutted cat vs straight pipes
 

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Ye i get what your saying about the inside of the cat but what im trying to find out is if i drop the cat and get out all the honey comb and other stuff in there will it be better i do that or just put in the str8 pipes ?? de gutted cat vs straight pipes
Gutting the cat would be my choice, sorry my reference about the honeycomb was to answer the post below:thumbsup

will gutting the cat improve perfomance???
 

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respect A20RYM thats my thought i think thats a better route to go
I used the single pipe replacement on my 4 cylinder 318is butif I had to do it on a 6 cylinder then I would just gut the cat section.

I have a Miltek de-cat section waiting to go on my coupe and you ought to see the size of the silencers on it:yikes



 

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a bit offtopic question. dont you put lambda probes on those? or are they mounted someplace else
 

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a bit offtopic question. dont you put lambda probes on those? or are they mounted someplace else
I realised that I was sent a de-cat section for an Evo that has lambda sensors in the manifolds.

I have to my Miltek section modified to create a home for the lambda sensors otherwise the car will not run at all well:frown

Well spotted:thumbsup, that was the main reason for me taking those pictures. I just decided to use them for reference purposes to show Yardie the size of the silencers on a M3 de-cat section compared to the size of the catalytic converters;)
 
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