# Looking for input about removed exhaust on a b5 s4



## Gone.T.eightI (Mar 22, 2006)

Hey guys, just looking for some input, hopefully some people that have done the same thing. I removed my catback on my 01 s4. Now I have put in techonics 2.5" downpipes with no cats. Currently there is no exhaust, just straight pipes. The gains are noticable and the sound is great. Under the car where the stock cats usually are, there are two bolts coming out of the undercarriage with large washers on them, seemingly with no use atm. I drilled through a skinny piece of flexible steel on both ends, and used that to support the downpipes. My questions for the people here are: has anyone done anything similar to support their downpipes after removing the exhaust, and if so, did you have issues and how did you get around them. Second, I need to know if the fact that the downpipes are ending right under the car, and causing much more extreme heat to the undercarriage, if I should worry about anything being hurt by the heat, or even things non-metal, melting. Any input would be greatly appreciated.
Another question I have is about adding cats later on, when you have catless downpipes. I have never heard anything like this, but is it possible to purchase or have cats custom made, to slip fit on both ends and have them after your downpipes, and then either modify an aftermarket exhaust or build one completely? I know as far as the work is concerned it can be done, and I am pretty sure it wouldn't cause any running issues. But is that an ok thing to do, putting cats after your downpipes and obviously they would not have 02 sensors in.
EDIT: the reason I would like to figure these things out now, is because if I can save myself from buying catback now and just rolll with no exhaust until I can build it, then I am going to get some mercs while I have the dough. If I am going to run into issues having my exhaust off BESIDES EMISSIONS, which i don't really care about, already have no cats... then I think my money would be better spent getting exhaust.


_Modified by Gone.T.eightI at 9:55 AM 9-16-2008_


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*

Why would you not care about emissions AND run no catback on the street? 
Running catless with open exhaust on the street saves you fractions of a second in a quarter mile.
There are a lot of options regarding downpipes, hi flow cats and cat back exhausts and most have been around for several years.
Why not do it right and get a set of downpipes with cats and test pipes along with a real catback. Then you can run cats on the street and pull your cats or run open dumps for tracking or the drag strip http://****************.com/smile/emthup.gif


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*

fractions of a second in 1/4 means nothing to me, as i could care less about ever going to the track unless its a real track... not a straight one







I can get around the emissions no problem, don't worry about that. The bottom line, is you will not get the same out of a catback, as you will running straight downpipes, not only because it is the least restrictive, but because taking off the weight of the catback DOES add horsepower even if it's minimal. My questions was not "would you do it", it was will I run into any problems with the heat underneath the car, or with the way I mounted something to help support them. Doing something "right" doesn't mean the way you would do it. Why have cats when you dont need it right? Trust me man, im not a moron, i know how exhaust works and what parts are on the market, but when you get better horsepower by removing a part, and not getting a new one, why waste your $ to make it legal. espesially when no cop is gonna stick his head under my car and say, hmmmm, you don't have cats... and if he does I will just get that inspection ticket signed and mailed without doing a thing.
http://****************.com/smile/emthup.gif 
anyone with some information that pertains to what I asked?


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_Why would you not care about emissions AND run no catback on the street? 
Running catless with open exhaust on the street saves you fractions of a second in a quarter mile.

Oh, and btw, even though I don't plan to track this car 1/4 mi too often... why would you argue that fractions of a second don't matter lol... Fractions of a second are everything.


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*


_Quote, originally posted by *Gone.T.eightI* »_fractions of a second in 1/4 means nothing to me


_Quote, originally posted by *Gone.T.eightI* »_why would you argue that fractions of a second don't matter lol... Fractions of a second are everything.

You missed the point and change opinions fast.

_Quote, originally posted by *Gone.T.eightI* »_Trust me man, im not a moron, i know how exhaust works and what parts are on the market, but when you get better horsepower by removing a part, and not getting a new one, why waste your $ to make it legal. espesially when no cop is gonna stick his head under my car and say, hmmmm, you don't have cats... and if he does I will just get that inspection ticket signed and mailed without doing a thing.
http://****************.com/smile/emthup.gif 
anyone with some information that pertains to what I asked?


When looking from underneath, maybe cut downpipes where they pass the subframe bending into the horizontal run. Cut rest of bend off scrap piece to re-weld back onto DP as a deflected dump, say pointed in direction of same side DP to rear wheels... kicks up serious WOT dust.
Easiest cut off DP at first bend horizontal to the ground, like running dumps off the hotsides http://****************.com/smile/emthup.gif 
Share with friends and link us some youtube











_Modified by GLS-S4 at 12:36 AM 9-17-2008_


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_
You missed the point and change opinions fast.
When looking from underneath, maybe cut downpipes where they pass the subframe bending into the horizontal run. Cut rest of bend off scrap piece to re-weld back onto DP as a deflected dump, say pointed in direction of same side DP to rear wheels... kicks up serious WOT dust.
Easiest cut off DP at first bend horizontal to the ground, like running dumps off the hotsides http://****************.com/smile/emthup.gif 
Share with friends and link us some youtube








_Modified by GLS-S4 at 12:36 AM 9-17-2008_

I never changed opinions, I said that to me, the 1/4 doesn't matter cause I don't race, but to people who do... fractions are what makes or breaks a win, or an improvement over other times.
Thanks for the input, and that w hat I had been thinking. If I completely decide to not ever do catback, which I am at that point almost lol, then I will be cutting like you said. Tha car is parked, dropped the trans last night to put in the rs4 clutch and VAST flywheel, after we do the timing belt kit ill put it all back together and get some video action.


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*


_Quote, originally posted by *Gone.T.eightI* »_I never changed opinions, I said that to me, the 1/4 doesn't matter cause I don't race, but to people who do... fractions are what makes or breaks a win, or an improvement over other times.

Thanks for clearing that up http://****************.com/smile/emthup.gif 
Why are you upgrading your car?


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*

well each upgrade is a different purpose. It was chipped with a hose kit when i got it, as well as having a trashed stock clutch at 100k. Had to do the clutch and flywheel, so i did rs4 clutch with VAST 12lb flywheel. 2.5 inch downpipes was because I already had to drop the trans to do the clutch, so wanted to get those out of the way now. I got the forge dv's cause im sure with a chipped s4 at 100k, the diaphragms are starting to go bad in those stock bosch's. Suspension because mine was stock at 100k and felt like crap, plus everything looks better lower







Motor mounts because it is an inexpensive and easy way to put down more torque, and have a more solid ride. Other then that stuff, all that I see in the future is side mounts, fueling, and k04's. I dont really plan to run it on the 1/4 track more then a few times, just to see what range I'm in etc... but I just want to do some basic mods so I can join audiclub and start doing some races with my local friends who race porches.


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*

Your going to race Porches with stock IC's and chipped 100K K03's ?
How long were you hoping to run it before replacing turbo's ?


_Quote, originally posted by *Gone.T.eightI* »_all that I see in the future is side mounts, fueling, and k04's.

Your tracking a B5 S4, you will need more parts http://****************.com/smile/emthup.gif


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_Your going to race Porches with stock IC's and chipped 100K K03's ?
How long were you hoping to run it before replacing turbo's ?

Your tracking a B5 S4, you will need more parts http://****************.com/smile/emthup.gif 

its going to be my daily driver always, i dont plan to get too crazy, im not racing porsches, just going to races with them, i would most likely be racing in a way less agressive class on the same track with them.


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*

Open downpipes, no cat back, racing, not 1/4 racing, maybe tracking, maybe a little street racing?, what legalities, some 1/4 racing, no cats, open exhaust, maybe cats later, could be daily driver, fractions of a second mean nothing and everything, maybe catback later, tracking with Porche friends, going to races with Porches, less aggressive racing with Porche friends but not racing Porches, daily driver always... It's proly just me but I'm a little confused








BTW, what is "less aggressive racing"?
Got pics or vid's of your modded DP's?


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_Open downpipes, no cat back, racing, not 1/4 racing, maybe tracking, maybe a little street racing?, what legalities, some 1/4 racing, no cats, open exhaust, maybe cats later, could be daily driver, fractions of a second mean nothing and everything, maybe catback later, tracking with Porche friends, going to races with Porches, less aggressive racing with Porche friends but not racing Porches, daily driver always... It's proly just me but I'm a little confused








BTW, what is "less aggressive racing"?
Got pics or vid's of your modded DP's?

Different cars race in different classes







I have seen stock sti's and stock s4's on the track that only have coils, and sometimes I see gti's with cup kits... You're starting so much contraversy over a modification you don't like... when it is the best way to get power out of an exhaust setup, and many people before me have done it. I'll get some vids when the trans is back in from the clutch job and we get the timing belt done. I can get pics too, but you can find pics of the DP's anywhere. They are straight from JHM, Techtonics 2.5" downpipes without cats. Most likely I will just roll around with the straight pipes how they are now. Sooner or later I plan to just make the exhaust in my buddy's shop, 2.5" true dual, no mufflers or resonaters, and as we already know, no cats







Straight pipes all the way, ftw http://****************.com/smile/emthup.gif


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_Open downpipes, no cat back, racing, not 1/4 racing, maybe tracking, maybe a little street racing?, what legalities, some 1/4 racing, no cats, open exhaust, maybe cats later, could be daily driver, fractions of a second mean nothing and everything, maybe catback later, tracking with Porche friends, going to races with Porches, less aggressive racing with Porche friends but not racing Porches, daily driver always... It's proly just me but I'm a little confused








BTW, what is "less aggressive racing"?
Got pics or vid's of your modded DP's?

And to clear up your misinterpretations: Yes open downpipes, no catback until we build it the right wat, a little racing cause its fun on the weekends every now and again, only gonna 1/4 race when the work is to a point where i wont be doing much for a while and I want to see what shes running, yeah i will probably start some **** on public roads, obviously i dont care about legalities - you can get around them, screw cats for ever - dont plan on ever having them, always gonne be a daily driver, and when i do go to the track i will be in the slower less aggressive and more passive class of cars(im not experienced, i just enjoy it). and there you have it.


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## GLS-S4 (Jun 6, 2005)

*Re: Looking for input about removed exhaust on a b5 s4 (Gone.T.eightI)*


_Quote, originally posted by *Gone.T.eightI* »_You're starting so much contraversy over a modification you don't like... 

Wrong assumption. I was TRYING to understand what your intended use is so that I could offer appropriate suggestions. In the spirit of supporting the B5 S4 and 2.7T engine platform, I offered you suggestions to what I interpreted as your questions, didn't I ?
Controversy commonly starts due to unclear communications








Now youtube some exhaust vids in front of the local cop shop


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## Gone.T.eightI (Mar 22, 2006)

*Re: Looking for input about removed exhaust on a b5 s4 (GLS-S4)*


_Quote, originally posted by *GLS-S4* »_Now youtube some exhaust vids in front of the local cop shop










haha sounds good, should have the trans back in tommorow, and then just gotta do the timing belt kit and I'll go make a vid.


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