Mods to standard exhaust system?

Westy

Westy

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I will be visiting an exhaust specialist very soon to get a fixing bracket replaced on the car as the back box is banging around where the old bracket has broken.

Anyway, I was thinking, is it worth me getting any other work done to the standard S3 exhaust system while I'm there? My mate is telling me to have the "middle box" removed and a straight piece of pipe put in its place!!! Is it worth getting down pipe done or any of that jazz? I currently have a stage 1 with silicone TIP and that's it.

T.I.A.
 
A common mod among the diesel boys is to have the back box removed giving a more raucous sound.

However on a standard exhaust you could take the midlle box out for added noise, alternatively you could do as one of my friends has done to his Z4, basically he has removed the back box (same size as the S3 one. huge) and removed all of the wadding inside. This gives a louder / sportier sound with a completley standard system.
 
Hi Westle, removing the centre box won't give you any performance gains. It'll make it slightly louder, not worth doing to be honest.

Getting a 3"downpipe with a sports cat will be money well spent. You could get a decat but when it comes round to the MOT you'll end up messing around trying to get it through the emissions test.

So.... 3"downpipe + sports cat + standard S3 system = standard look outside but a much less restricted system with a much nicer roar!!! :)
 
Il post a pic when I get home of mine, it's epic and sounds the dogs.

I basically cut as much of the back box off as I could, right up to the acual pipe, then cut all baffles and sound proofing out of it, then made a plate for the side of it and welded it on, so now it's a small hollow box.
I was booked to get a proper one made that's why I did it, but then I decided to go to Germany and it's been like that ever since. The difference in response ofthe engine was substantial too.
 
Thanks sandip. I didn't think it would have any effect on performance at all but thought it might be slightly less restrictive. Also just after the centre box the exhaust seems to go into a narrow squashed part, surely this is restrictive too?
 
I have a 3" downpipe with a de cat mated to a standard cat back without no silencer but just the backbox so no sliencer just a backbox. Looks standard but sounds very nice and not to loud were its OTT
 
superkarl said:
Il post a pic when I get home of mine, it's epic and sounds the dogs.

I basically cut as much of the back box off as I could, right up to the acual pipe, then cut all baffles and sound proofing out of it, then made a plate for the side of it and welded it on, so now it's a small hollow box.
I was booked to get a proper one made that's why I did it, but then I decided to go to Germany and it's been like that ever since. The difference in response ofthe engine was substantial too.
Click to expand...


Yes please matey. Some pictures would be great. Is it much louder than the standard system because I'm getting too old for all that noise ;)
 
Westle said:
Thanks sandip. I didn't think it would have any effect on performance at all but thought it might be slightly less restrictive. Also just after the centre box the exhaust seems to go into a narrow squashed part, surely this is restrictive too?
Click to expand...

Yeah that stupid squashed bit lol

The squashed bit is not as restrictive as the 2 1.8inch downpipes lol

I'll try and post a video of mine up later, should give you a rough idea what yours will sound like
 
Yours sounds good Sandip, pipeworx do dam good jobs.

To be honest westle it is a little boomy, if I wer to do it again, I would halve the box, but leave some baffles still in there to deaden the drone. When it's on song though, it sounds awesome, just pure roar.

I think I'm going to find another standard cat back and do the above.
 
I got a relentles one which I wouldnt recommend. Its fine now but too much fiddling. Save bit longer and get a piperwerx
 
superkarl said:
Yours sounds good Sandip, pipeworx do dam good jobs.

To be honest westle it is a little boomy, if I wer to do it again, I would halve the box, but leave some baffles still in there to deaden the drone. When it's on song though, it sounds awesome, just pure roar.

I think I'm going to find another standard cat back and do the above.
Click to expand...

You can have my old one for a small fee if you want? Cleaned it up and sprayed the back box in heat resistant paint, let me know bud :)
 
How much is a small fee?? Because I'm not entirely sure my current one will pass mot, or at least I don't want to chance wasting an mot for it to fail.
I was looking at one on eBay yesterday for 99p lol. Sooooo how's £1.50 sound? Lol just kidding
 
superkarl said:
How much is a small fee?? Because I'm not entirely sure my current one will pass mot, or at least I don't want to chance wasting an mot for it to fail.
I was looking at one on eBay yesterday for 99p lol. Sooooo how's £1.50 sound? Lol just kidding
Click to expand...

Pm'd
 
s3dave said:
Taking the middle box out for a straight pipe in a standard system will make it drone and do your head in......
Click to expand...

I think i'll be leaving it in if there's no advantage to have it removed.

I've been getting prices and I also think I'll be leaving my exhauust alone till something needs replacing! For the moment I'll just get the bracket fixed and save my cash for my FMIC and suspension to get done before my annual Nurburgring trip.
 
s3dave said:
Taking the middle box out for a straight pipe in a standard system will make it drone and do your head in......
Click to expand...

I effectively have a straight pipe from the turbo to the back box and have no drone at all. Quiet when cruising around town with a little rumble and a nice loudness when at full throttle.
 
Rarrrrr that sounds wicked sandip! Hmmm maybe I'll enquire about the mid section. My friend at work has had the mid section on his Leon FR removed and it improved the sound soooo much. Thanks for posting that vid
 
this is what i did, carnage!.....
P2030051.jpg


and heres the sound, not that the camera picks it up well...


i must have saved about 25kg doing it aswell haha.
 
haha, looks naff as hell, didnt paint or smooth it off as it was only supposed to be a temporary measure. but yeh, does sound good, when its going, windows down, i love it.
 
Karl you're mental haha. That does sound a bit fruity, but you say you've not had an MOT since doing that! Think I'll look into just getting the mid section removed for the time being and see how that is.

Cheers for your pics and vids guys
 
ha, i literally attacked it with a circular saw and grinder, was a good idea for about 30 mins.
no i've not had an mot with it, but after my mot with a standard one i might start again, cut it in half, but leave all baffle pipes in it.
its good fun chopping things up
 
should sound bit more throaty with the centre silencer removed.

I think my setup is a good compromise between sound and loudness.
 
Ok guys I just got my exhaust fixed in the end! I did some VCDS loggin on my way to the exhaust place and it seemed to point at a nackered MAF so I saved my money and went to Audi to get a new MAF. I think I'll forget the exhaust untill it needs sorting.
 
Can anyone tell me what size decat I need for a standard S3 8p Exhaust system ? 3.5" or smaller? Thanks
 
vanilla_ice said:
Does anyone else run this exact setup?

Would be interested to hear your feedback.

Thanks.
Click to expand...

For a while yeah. Standard exhaust has shown in the past to become restrictive around 300 bhp with ever rising EGT’s so it depends how far you want to push for power.
 
JonnyDerv said:
For a while yeah. Standard exhaust has shown in the past to become restrictive around 300 bhp with ever rising EGT’s so it depends how far you want to push for power.
Click to expand...

I'm not planning on changing turbo from the standard K04, so sub 300bhp.

Any feedback on the noise of the setup? Was it "boomy", "droney" or "raspy" etc?
 
vanilla_ice said:
I'm not planning on changing turbo from the standard K04, so sub 300bhp.

Any feedback on the noise of the setup? Was it "boomy", "droney" or "raspy" etc?
Click to expand...

I ran 280 with that set up fine. We’re talking about 3 and a half years ago now so I can’t remember specifically. It certainly wasn’t droney or boomy. From what I can remember it sounded more throaty, more turbo whistling on spool up from the downpipe. It sounded good in my opinion, quiet pootling about and nice when giving it some beans. Depends what you like I guess, I preferred my resonated Milltek on my big turbo set up than the non resonated.
 
Thanks @JonnyDerv. 'Sounds' encouraging. What's remained in check for you?

I don't mind it sounding more 'sporty', I just don't want it to sound like a boy racer, drawing attention etc.
 
Lol I see what you did there ;).

In what way do you mean what’s remained in check?

It definitely doesn’t sound boy racer or draws unwanted attention. It sounds very oem+ in my opinion.
 
audi upgrades
It was such a long time ago but I don’t remember having any issues. I pushed the standard cat back to just over 300 bhp temporarily. But I’m sure I was fine around 280 bhp. Obviously it depends on your own set up and the mapping but I can’t see you having any issue under 300 bhp.

Tufty and Bill I’m sure will have data logs for the stock cat back’s EGT’s.
 
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