Pre cats and clutch pipe

4.2 V8 32v Naturally Aspirated - 414 bhp
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FrazerD
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Pre cats and clutch pipe

Post by FrazerD » Tue May 07, 2019 9:25 pm

Hi folks,

I am having a bit of a dilemma in my mind and I’m not sure if I’m over thinking things but I’m looking for another perspective.

I’m planning a map and although most of you will say stage 2 MRC live map, I feel I’m not after that and a stage 1 map to change the power delivery is what I want. This is where my dilemma begins, do I gut the pre cats to compliment the map and while the down pipes are out replace the clutch return pipe.

I’m in two minds between doing preventative maintenance and just spending money for the sake of it so will gutting the pre cats compliment a stage 1 map enough to justify the cost of dropping them. If I do, is it worth changing the clutch return pipe while I’m there or does this not prevent enough to warrant the cost.

I know this might sound trivial but I’m just open to another set of eyes.

Cheers :thumbs:

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Covkiller
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Re: Pre cats and clutch pipe

Post by Covkiller » Tue May 07, 2019 9:47 pm

Gutting your pre cats will help with flow for a Stage 1 remap and improve power. You could always get cat bypass pipes and keep your cats. This is what I've done. On my first visit to MRC with my Mug Blue RS4, I had bypass pipes fitted, a full carbon clean and the inlet manifold cleared, ported and polished, with the flaps left in tact and no cold air feed, BMC filter and a remap and got 442PS.
Why change the clutch return pipe if you have no problem. I only changed mine for an OEM one when I had my clutch changed.
RS4 B7, Mugello Blue, K&W V3 & HR ARBs, set up by Centre Gravity, Milltek Valved Non Res & cat bypass pipes, BMC air filter, braided hoses, DOT 5.1, Terraclean, MRC Full Carbon Clean, MRC remap 448PS 477NM, 20" S7 alloys with 4mm spacers & Hawke spigots 66.6 > 57.1, AP Racing front discs. Sold Sept 2019. Now rocking an F80 M3

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FrazerD
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Re: Pre cats and clutch pipe

Post by FrazerD » Tue May 07, 2019 10:10 pm

Covkiller wrote:
Tue May 07, 2019 9:47 pm
Gutting your pre cats will help with flow for a Stage 1 remap and improve power. You could always get cat bypass pipes and keep your cats. This is what I've done. On my first visit to MRC with my Mug Blue RS4, I had bypass pipes fitted, a full carbon clean and the inlet manifold cleared, ported and polished, with the flaps left in tact and no cold air feed, BMC filter and a remap and got 442PS.
Why change the clutch return pipe if you have no problem. I only changed mine for an OEM one when I had my clutch changed.
If I’m going to drop the down pipes I’ll just gut the pre cats and be happy with that. I don’t want to get carried away because I feel like if I do it will be for the wrong reasons. The reason for changing the pipe would be because I’m in there and try to prevent a sticking clutch. I appreciate there are different views on this, hence the perspective.

Would you leave it alone until if or when the clutch caused an issue? Do you think the gains from gutting the pre cats warrants the cost of doing them?

Cheers :thumbs:

mikep99
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Re: Pre cats and clutch pipe

Post by mikep99 » Tue May 07, 2019 10:13 pm

I think you'd be best going stage 2 if you gut the precats as per the MRC website - http://www.mrctuning.com/index.php/audi ... /rs4-b7-2/

Mike

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FrazerD
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Re: Pre cats and clutch pipe

Post by FrazerD » Tue May 07, 2019 10:58 pm

mikep99 wrote:
Tue May 07, 2019 10:13 pm
I think you'd be best going stage 2 if you gut the precats as per the MRC website - http://www.mrctuning.com/index.php/audi ... /rs4-b7-2/

Mike
I’m not going stage 2 though so it comes down to if it warrants gutting them with a stage 1 map or if there’s not much to gain then it’s just money down the drain.

Cheers :thumbs:

mikep99
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Re: Pre cats and clutch pipe

Post by mikep99 » Tue May 07, 2019 11:04 pm

I wouldn't bother gutting them with a stage 1 tbh.
keep the hardware stock.

Mike

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FrazerD
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Re: Pre cats and clutch pipe

Post by FrazerD » Tue May 07, 2019 11:31 pm

mikep99 wrote:
Tue May 07, 2019 11:04 pm
I wouldn't bother gutting them with a stage 1 tbh.
keep the hardware stock.

Mike
Thanks for your input. And would you replace the clutch return pipe if there were no symptoms therefore gutting the pre cats would make sense as the downpipes would be off? Or just leave well alone and cross the bridge if or when I get to it?

Cheers :thumbs:

mikep99
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Re: Pre cats and clutch pipe

Post by mikep99 » Tue May 07, 2019 11:47 pm

I can understand your train of thought here but personally, I'd leave the clutch pipe alone if you're not having any problems.
Suppose you could think another step ahead and change the clutch etc as you'd be changing the pipe.... It never ends.

Once the downpipes are out, they should be a lot easier to remove next time. The issues arise with corroded studs that haven't been touched since the car was built.

Mike

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FrazerD
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Re: Pre cats and clutch pipe

Post by FrazerD » Wed May 08, 2019 6:50 am

mikep99 wrote:
Tue May 07, 2019 11:47 pm
I can understand your train of thought here but personally, I'd leave the clutch pipe alone if you're not having any problems.
Suppose you could think another step ahead and change the clutch etc as you'd be changing the pipe.... It never ends.

Once the downpipes are out, they should be a lot easier to remove next time. The issues arise with corroded studs that haven't been touched since the car was built.

Mike

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Thanks for you input again, it’s appreciated. I know what you mean about it never ending and that’s why I wanted another perspective. Trying to find the line between preventative maintenance and just spending for the sake of it.

Cheers :thumbs:

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