REPOST, Need link or info to gut Precats????

2low4snow · 11-10-2004, 09:41 AM

OCA::DIY Motorsports · 11-10-2004, 10:11 AM

I'll bet NO ONE will post anything re: this! Not sure why. Why isn't there a write up in the tech section? When I do mine, I write one up and see if they post it...I'll bet they don't.

A few possible reasons:

1. Technically warranty voiding(as are lots of other things too) so the mods don't want to support it?

2. A very prominant person here makes money doing the conversion and might not want to let people see just how simple the process is?(I doubt this and personally don't want to believe this BTW)

3. The legend of how difficult a job it is scares people from doing it so not many have attempted it.

4. It does take some air tools and a welder to make the job efficient so again, not many people attempt the job.

You make the decission. I'll be interested to see what happens.

lemieux@curbside · 11-10-2004, 10:17 AM

and i think he's the first one entitled to answear this or not.
i even asked him for couple tips ..he never answered me .

OCA::DIY Motorsports · 11-10-2004, 10:23 AM

"this is piggies stuff" HUH??? Who owns a tech procedure??!!!

All for one and one for all right??

lemieux@curbside · 11-10-2004, 10:34 AM

it took me 2 hours of hard work , 1 hour each time for each downpipe.
what i did is used a wide chisel and a big hammer to cut in the material, and a big long/curved thin nose pliers to pull stuff out. i first cut the precat (metal wave sheet rolled/folded or carrugated)and pulled the middle part out .
the most difficult part is cutting (driving the big chisel) through the entire cat (find the best angles to do that) and pull that middle piece out. you have to cut everything around it so you can pull it out (make the big cuts with the chisel and finish it up with a wide screwdriver -it's thinner and will fit all around the middle cut section)
after taking the middle section out the sides will collapse toward the inside.
make sure you cover your mouth because that dust is really bad.

AudiS4guy - NorCal · 11-10-2004, 10:48 AM

sensors and tap new one after the main cats. No offense really but this has been done way before piggies time so I don't know why people think of it as Piggie's procedure? Just punch all the crap out inside the cats with a screw driver or whatever you think might work until it's hollow like a straight pipe. Its taking off the downpipes thats the pain in the ass. I'd send mine into have Mike do them because my ass is lazy =)

Funkweasel · 11-10-2004, 10:58 AM

saw and go down the center of the precat. Take that bit out. Then use a large screwdriver and hammer to cut the remaining cat material into 3 sections or so. Lever, wedge, and bludgeon the rest out. Use a wire flapper or other spinning abrasive to remove the little bits that will be left on the walls of the precat. You can smooth out the entry a little if you're anal.

Install O2 bungs behind the cats, both facing towards the inside of the car. Slightly angle them down or up (your choice). Bolt in O2 plugs to the old secondary O2 location.

Install.

;-) Tedious and annoying(have a powerful drill) but not hard.

2low4snow · 11-10-2004, 11:08 AM

Swank4 · 11-10-2004, 11:08 AM

so I find the "piggie's terf" reasoning a little ridiculous.

Swank4 · 11-10-2004, 11:15 AM

11-10-2004, 09:41 AM	#1
2low4snow Audiworld Junior Member Account #: 65937 Join Date: Nov 2003 Posts: 697	REPOST, Need link or info to gut Precats????

11-10-2004, 10:11 AM	#2
OCA::DIY Motorsports Member Account #: 60276 Join Date: Aug 2003 Posts: 5,655	This is the craziest thing. People ask all the time and there is never a response. I'll bet NO ONE will post anything re: this! Not sure why. Why isn't there a write up in the tech section? When I do mine, I write one up and see if they post it...I'll bet they don't. A few possible reasons: 1. Technically warranty voiding(as are lots of other things too) so the mods don't want to support it? 2. A very prominant person here makes money doing the conversion and might not want to let people see just how simple the process is?(I doubt this and personally don't want to believe this BTW) 3. The legend of how difficult a job it is scares people from doing it so not many have attempted it. 4. It does take some air tools and a welder to make the job efficient so again, not many people attempt the job. You make the decission. I'll be interested to see what happens. __________________ SUPPORT STEM CELL RESEARCH! "There are (shop)whores that do provide a valuable service. However, you appear as a whore with no orifices, therefore all you accomplish is space occupation." --Kartman "Those who would give up ESSENTIAL Liberty to purchase a little temporary safety, deserve NEITHER liberty nor safety" Benjamin Franklin

11-10-2004, 10:17 AM	#3
lemieux@curbside AudiWorld Super User Account #: 47312 Join Date: Dec 2002 Posts: 17,783	i did it my self... it was so-so (2 hours total) .. i didn't ask anyone, this is piggie's stuff and i think he's the first one entitled to answear this or not. i even asked him for couple tips ..he never answered me . __________________ ************************************************ ************************************* "it's a B5 S4 ,it may break down, but its far enough ahead, by the time its fixed, you still haven't caught up." -best line i've heard ;) AUDI B5 S4 detail info (pdf file) that everyone should read and have saved on his computer AUDI B5 RS4 study guide detail info (pdf file) FATS database VAG-COM LOCATOR ASP Hands down the "BESTEST" tuner out there.

11-10-2004, 10:23 AM	#4
OCA::DIY Motorsports Member Account #: 60276 Join Date: Aug 2003 Posts: 5,655	See #2..... "this is piggies stuff" HUH??? Who owns a tech procedure??!!! All for one and one for all right?? __________________ SUPPORT STEM CELL RESEARCH! "There are (shop)whores that do provide a valuable service. However, you appear as a whore with no orifices, therefore all you accomplish is space occupation." --Kartman "Those who would give up ESSENTIAL Liberty to purchase a little temporary safety, deserve NEITHER liberty nor safety" Benjamin Franklin

11-10-2004, 10:34 AM	#5
lemieux@curbside AudiWorld Super User Account #: 47312 Join Date: Dec 2002 Posts: 17,783	yes in my opinion.. but most are not that way here... it took me 2 hours of hard work , 1 hour each time for each downpipe. what i did is used a wide chisel and a big hammer to cut in the material, and a big long/curved thin nose pliers to pull stuff out. i first cut the precat (metal wave sheet rolled/folded or carrugated)and pulled the middle part out . the most difficult part is cutting (driving the big chisel) through the entire cat (find the best angles to do that) and pull that middle piece out. you have to cut everything around it so you can pull it out (make the big cuts with the chisel and finish it up with a wide screwdriver -it's thinner and will fit all around the middle cut section) after taking the middle section out the sides will collapse toward the inside. make sure you cover your mouth because that dust is really bad. __________________ ************************************************ ************************************* "it's a B5 S4 ,it may break down, but its far enough ahead, by the time its fixed, you still haven't caught up." -best line i've heard ;) AUDI B5 S4 detail info (pdf file) that everyone should read and have saved on his computer AUDI B5 RS4 study guide detail info (pdf file) FATS database VAG-COM LOCATOR ASP Hands down the "BESTEST" tuner out there.

11-10-2004, 10:48 AM	#6
AudiS4guy - NorCal Member Account #: 79060 Join Date: Aug 2004 Posts: 3,273	Whats so hard about gutting the cats? Gut it like you gut anything and weld over the secondary o2.. sensors and tap new one after the main cats. No offense really but this has been done way before piggies time so I don't know why people think of it as Piggie's procedure? Just punch all the crap out inside the cats with a screw driver or whatever you think might work until it's hollow like a straight pipe. Its taking off the downpipes thats the pain in the ass. I'd send mine into have Mike do them because my ass is lazy =) __________________ My FATS Tests Stock Software - Before and After Tweaks AMS - Before and After Tweaks AMS part 2 - Before and After Tweaks REVO & TAP- Before and after tweaks APR - Before and after tweaks Ign timing testing AIM: AudiS4guy

11-10-2004, 10:58 AM	#7
Funkweasel AudiWorld Super User Account #: 28517 Join Date: Nov 2001 Posts: 10,145	There just isn't a "procedure". I've probably responded to 5 or 6 of these posts. Use a 1.5" hole saw and go down the center of the precat. Take that bit out. Then use a large screwdriver and hammer to cut the remaining cat material into 3 sections or so. Lever, wedge, and bludgeon the rest out. Use a wire flapper or other spinning abrasive to remove the little bits that will be left on the walls of the precat. You can smooth out the entry a little if you're anal. Install O2 bungs behind the cats, both facing towards the inside of the car. Slightly angle them down or up (your choice). Bolt in O2 plugs to the old secondary O2 location. Install. ;-) Tedious and annoying(have a powerful drill) but not hard.

11-10-2004, 11:08 AM	#8
2low4snow Audiworld Junior Member Account #: 65937 Join Date: Nov 2003 Posts: 697	So when you drill out the precat material in chunks, you can shake it out to come back out the top??

11-10-2004, 11:08 AM	#9
Swank4 AudiWorld Super User Account #: 41738 Join Date: Aug 2002 Location: San Francisco Posts: 6,760	With all due respect to piggie, gutting a pre-cat isn't a novel concept for auto exhausts... so I find the "piggie's terf" reasoning a little ridiculous. __________________ 2001 S4 avant / RS6-K04 turbos / ASP custom tuning / Fast Intentions 3" downpipes / AWE Twin2 exhaust / AWE ICs / Aquamist HFS-5 / SPEC 3+ clutch / Stasis Motorsports (Ohlins) 700F/800R / Stasis Alcon 355 BBK, 298 rears / H-sport rear sway / Stasis 4:1 rear diff / Zeitronix wideband O2 / FATS = 3.35 on 91 octane / Land & Sea dyno = 429 whp.

11-10-2004, 11:15 AM	#10
Swank4 AudiWorld Super User Account #: 41738 Join Date: Aug 2002 Location: San Francisco Posts: 6,760	How harmful is the dusty cat material that's being removed? Seems like this would go everywhere. __________________ 2001 S4 avant / RS6-K04 turbos / ASP custom tuning / Fast Intentions 3" downpipes / AWE Twin2 exhaust / AWE ICs / Aquamist HFS-5 / SPEC 3+ clutch / Stasis Motorsports (Ohlins) 700F/800R / Stasis Alcon 355 BBK, 298 rears / H-sport rear sway / Stasis 4:1 rear diff / Zeitronix wideband O2 / FATS = 3.35 on 91 octane / Land & Sea dyno = 429 whp.

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