Decat Pipe - Noise Increase?

Toshers

Toshers

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What level of noise increase have people experienced fitting a decat pipe? I have the Audi sports exhaust which I will be keeping from the cat back but wondering what impact the decat will have? I still need the car to be sociable in the mornings lol
 
Toshers said:
What level of noise increase have people experienced fitting a decat pipe? I have the Audi sports exhaust which I will be keeping from the cat back but wondering what impact the decat will have? I still need the car to be sociable in the mornings lol
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If the standard Sports Exhaust is 6, the decat takes that upto 10 on full throttle. It is loud, and it is loud on cold start.

Under normal driving conditions in D and comfort, there's little to no difference. In dynamic part throttle it's maybe 8/10. In dynamic under full WOT, it's 10/10 loud, but in a nice way.

You will unfortunately suffer more from the dreaded "WG rattle" that becomes very noticeable without a cat masking it.
 
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Leo-RS said:
If the standard Sports Exhaust is 6, the decat takes that upto 10 on full throttle. It is loud, and it is loud on cold start.

Under normal driving conditions in D and comfort, there's little to no difference. In dynamic part throttle it's maybe 8/10. In dynamic under full WOT, it's 10/10 loud, but in a nice way.

You will unfortunately suffer more from the dreaded "WG rattle" that becomes very noticeable without a cat masking it.
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Ah, so it’s not my exhaust valves rattling under load at low speed but the wastegate? Tappety noise
 
If it’s the same noise as the cold start noise then it’s rumoured to be the turbo WG.

You should know if it’s coming from in front of you or behind you though haha.
 
I have to admit I haven't had the car long enough to experience the WG rattle!

Surely it's possible to modify it out?
 
I get the dreaded rattle, and it's definitely from the front of the car.
 
I haven't heard any sort of rattle in mine, and I'm really OCD with any kind of sounds like that (that passengers can never hear). Must be one of the lucky ones.
 
Is this for facelift ? I thought they didnt have 2ndary cats ? or are we referring to the main ones ?
 
All facelift cars will sound terrible on cold start. The noise silences after about 45secs.

In a decatted car, (main cat removal) the sound is present under part throttle conditions between around 20-70% throttle position. It’s the same type of rattle as you experience from the cold start.

The sound is always there, even with the car completely standard, it’s just the main cat masks it under normal driving. Some people with good ears claim they can hear it even with a standard car.

As far as I’m aware the only fix is by opting for a big turbo change, mapping apparently cannot stop it. It’s claimed to be from the wastegate but some are sceptical, it’s definitely in and around that area and definitely turbo related.
 
Leo-RS said:
All facelift cars will sound terrible on cold start. The noise silences after about 45secs.

In a decatted car, (main cat removal) the sound is present under part throttle conditions between around 20-70% throttle position. It’s the same type of rattle as you experience from the cold start.

The sound is always there, even with the car completely standard, it’s just the main cat masks it under normal driving. Some people with good ears claim they can hear it even with a standard car.

As far as I’m aware the only fix is by opting for a big turbo change, mapping apparently cannot stop it. It’s claimed to be from the wastegate but some are sceptical, it’s definitely in and around that area and definitely turbo related.
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I dunno, not in all cases, I get the same rattle during driving if the car is in comfort mode (flaps closed) and under part throttle at speed. I can make the sound completely vanish by changing to dynamic and opening the flaps.

So, I think when some people talk about this, they legit still have valve rattle from the rear under driving conditions.

I'm tempted to open my valve boxes and put springs in there so there is some tension on the valves. I can completely stop the rattle if I am on the ground and put my finger lightly on the valve pivot pin on the back of the exhaust. There was a brief youtube video floating around somewhere showing some guy putting a spring in there, I think it was Italian or some such.
 
Leo-RS said:
If it’s the same noise as the cold start noise then it’s rumoured to be the turbo WG.

You should know if it’s coming from in front of you or behind you though haha.
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It sounds like the middle of the car, like the cold start rattle.
 
When you start the car in the morning and put it in dynamic to stop the rattle noise look at the boost gauge.......you'll see the minute you put it into dynamic its's building a small amount of boost, the minute the rattle stops at 20 secs or so the boost reading stops.
 
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Personally I find the the exhaust to be loud enough for me. Every time I open the exhaust and give it some juice, I notice that heads on the street turn.

I actually prefer to be a little more stealth when being a little naughty on the road.

But granted I wouldn't mind a bit of a burble at low range engine speeds when ambling along. But I don't mind the lamboesque moan it has a low revs, it's rather unique.
 
PFL and added the secondary de-cat pipes with the Sporst exhaust. As has been said cold start is louder than ever - shame this cant be coded out. Normal driving in comfort, very little difference, but in dynamic, sound like the devil is under the bonnet, just sound epic! Get some really loud pops and bangs, and the noise under full throttle is nothing short of ‘mini supercar’!
 
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I’m having a Rogue Performance Decat Fitted on my FL tomorrow, the Sports Exhaust has already been de-resonated, and had the backbox made straight through and the sound deadening material removed so it should sound epic
 
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penetrator said:
I’m having a Rogue Performance Decat Fitted on my FL tomorrow, the Sports Exhaust has already been de-resonated, and had the backbox made straight through and the sound deadening material removed so it should sound epic
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You have big kahoonas or very tolerant neighbours! Would be too loud for me I think. Would still like to see and hear a video clip mind you...
 
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penetrator said:
I’m having a Rogue Performance Decat Fitted on my FL tomorrow, the Sports Exhaust has already been de-resonated, and had the backbox made straight through and the sound deadening material removed so it should sound epic
Click to expand...

So you’ve made it as loud as humanly possible lol? Brilliant
 
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Not a fan of the M3 exhaust sound
Sounds really hollow and not a patch on the RS3
 
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Mine is standard down pipe secondary decat and rs back box
Comfort is fine and quiet in the cabin and just normal volume of the rs on the outside
Dynamic is boarderline asbo sometimes! Sometimes it seems louder then other times

Start up is fine but can be a little awkward at 5 in the morning as it is super loud
 
So yesterday I went to get my Decat fitted at CLP Automotive in Sheffield, great place with some good lads. After sitting in there restroom for over 2hrs one of the lads came out to me with the glorious news that.....it doesn’t fit!!!
I initially laughed thinking he was joking, however he fooking wasn’t. I went and had a look for myself and there was about 1.5” gap from the fitted downpipe to the mid section.
The guys tried several things to get this to fit however you can’t just disappear that gap so it had to come off and the lad had to put everyth8 g back to normal. At this point I was absolutely ****** raging as I had purchased a Decat for my spec car and it didn’t fit, also I had to still pay for labour, so the phone calls commenced to the supplier...

So to cut this collamity short, the supplier of the Decat held there hands up and said there’s probably been a mix up with the pairing of downpipe and midsection as there numbered as a pair from the manufacturer etc. So the labour cost was paid by the supplier who passed that on to manufacture etc, I spent 6hrs at clp with no end product apart from having the transmission dogbone insert fitted. I was supposed to have my springs fitted too but obviously that didn’t happen!!

Going forward the supplier has offered to fit the DP and springs for free as they’ve got a new one on its way to them, caveat being I have to take my car to Scotland lol
 
Nightmare mate! What brand of downpipe was it? What was your aim with having it fitted at the moment, not sure Revo have the stage 2 map out yet?
 
Stage 2 isn't out yet but they do have a pipe file for stage 1 (1+) available that will eliminate the decat fault code.
 
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