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Original exausts without pre cats.
Posted: Fri Jun 29, 2007 8:13 pm
by paulito1
Hi everyone.
Please tell me if someone have tried to take off just the pe cats in an original exaust.
I ear something about that and they say thay you will get more torque and HP.
Some informations will be apreciated before i cut mine!

Thanks
RE: Original exausts without pre cats.
Posted: Fri Jun 29, 2007 8:30 pm
by derdle
I've just had my precats degutted but then remapped. Standard exhaust. I think the consensus will be that you should have a remap afterwards......but I will be guided by people who know better than me!
Paul
RE: Original exausts without pre cats.
Posted: Sat Jun 30, 2007 12:27 am
by RS SYED
whats the process of gutting the precats?
regards
RE: Original exausts without pre cats.
Posted: Sat Jun 30, 2007 8:36 am
by derdle
Easy to gut the precats......Doug.
I took mine to MRC to have it done. There is a thread somewhere about gutting precats, but am in a hurry and can't locate it yet for you. Hopefully someone else will know of that thread and will post a link for you.
Paul
Posted: Sat Jun 30, 2007 9:33 am
by Jarv
And how do you rate the MRC remap against the MTM one Paul? Blatant threadjack I know, sorry.
Precats
Posted: Sun Jul 01, 2007 11:19 pm
by quattrosteph
Done it on mine and had a rolling road done after to compare. It does increase the torque a lot . Precats are right at the exit of the turbo's wish is not good for the flow, and precats keep the heat near the turbo's wish is bad as well.

RE: Precats
Posted: Mon Jul 02, 2007 6:50 am
by fletchie55
gutting the pre-cats on an RS4 exhaust isnt that easy because they are 400cell and therefore fairly solid compared to other pre-cats on S4 for example, it can be done with a decent drill and some decent large drill bits, many people use auger bits I think.
you dont need a remap for this mod to take an effect, removing the pre-cats will instantly reduce the backpressure allowing the turbos to spool up faster, and will make the engine more 'free-revving'. If you are thinking of having a custom re-map at some point anyway, then it would be better to have it after gutting the pre-cats than before.
Precats..
Posted: Mon Jul 02, 2007 4:26 pm
by quattrosteph
the easy part is to get the precats out as it is soft to drill !!! the hard work is to get the down pipes out and back in !!!!! Because it is a real pain in the ass !!

Especially if you have big fingers!!
RE: Precats..
Posted: Mon Jul 02, 2007 6:36 pm
by Newdub
Does having them gutted make much difference to the sound? i.e any louder if so does it sound any good/bad
Precats
Posted: Thu Jul 05, 2007 7:50 pm
by quattrosteph
After the mod it does sound a little bit more raw inside, like a sport car should be

RE: Precats
Posted: Fri Jul 06, 2007 9:47 am
by fletchie55
and you'l here the whistle of the turbos much more!
RE: Precats
Posted: Fri Jul 13, 2007 5:28 pm
by quattrokid1
shh!! dont tell the Mrs:)
RE: Precats
Posted: Fri Jul 13, 2007 10:46 pm
by musty1
did anybody find the thread that derdle was talking about?