DP/Decat - Added noise?

[TomBlueS3]

Hi all,

I’ve been really struggling with trying to get the right amount of noise from my S3, when I first got it I disabled the flaps via VCDS (tiny improvement), not happy with this I then got the resonator delete (really good inexpensive mod just an awful drone at motorway speeds), again still not happy with this I then purchased a cat back resonated Cobra exhaust.

Review of the Cobra from the outside when someone else is driving it sounds epic. Not ricer loud but sounds deep and really good. The sound inside isn’t as loud but unfortunately there is still that drone at motorway speeds (albeit not as loud as res delete) so now I’m going to be putting the standard resonater back in and just having the Cobra back box.

Will adding a downpipe/decat increase cabin/drone noise? Or will it just be louder from the outside?

Looking at the future for Stage 2 hence the DP. I don’t want to go back to stock backbox as I really like the tips on the Cobra.

So anyone with a decat and/or experience comment please. As for the drone it’s that stupidly annoying loud noise at the 3k mark on load. Cheers.

 

[oli356]

I can't help much, but as for motorway noise.. .having valves shut with res delete makes quite a difference!

 

[Adam14]

Did you get the Res delete with anti drone? That's what I have and don't get any drone on the motorway/dual carriageway.

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[AlS3BE]

Not trying to sound like a a$$
At 3k rpm you will be cruising at 90mph+ so maybe cruise at a lower speed.

Other things to be aware of is the res delete and downpipe is up front so nearer to you as the driver. The drone can only get worse up front without resonators and cat as these coupled with the turbo surprisingly surpresses a lot of noise/drone.
Your cat back sounds great cause that’s tuned to let certain sounds and frequencies through, easily tweaked with size of box and baffles inside. More difficult to do with what is essentially a straight through pipe to the cat. Always trade offs tuning and generally messing about with cars but that’s the stuff we enjoy.

 

[BCS Nige]

I know it doesn't help but we supply all of our products with anti-drone built in ;-)
makes you wonder why other brands don't...
Cheers
Nige

 

[oli356]

Not trying to sound like a a$$
At 3k rpm you will be cruising at 90mph+ so maybe cruise at a lower speed.

Other things to be aware of is the res delete and downpipe is up front so nearer to you as the driver. The drone can only get worse up front without resonators and cat as these coupled with the turbo surprisingly surpresses a lot of noise/drone.
Your cat back sounds great cause that’s tuned to let certain sounds and frequencies through, easily tweaked with size of box and baffles inside. More difficult to do with what is essentially a straight through pipe to the cat. Always trade offs tuning and generally messing about with cars but that’s the stuff we enjoy.

In PFL at least mine is 3K rpm at like 80, so yeah..

 

[AlS3BE]

In PFL at least mine is 3K rpm at like 80, so yeah..

Ahh... didn’t think about that. Not driven a PFL so assumed it was the same or similar ratios to the FL.

 

[TomBlueS3]

Not trying to sound like a a$$
At 3k rpm you will be cruising at 90mph+ so maybe cruise at a lower speed.

Other things to be aware of is the res delete and downpipe is up front so nearer to you as the driver. The drone can only get worse up front without resonators and cat as these coupled with the turbo surprisingly surpresses a lot of noise/drone.
Your cat back sounds great cause that’s tuned to let certain sounds and frequencies through, easily tweaked with size of box and baffles inside. More difficult to do with what is essentially a straight through pipe to the cat. Always trade offs tuning and generally messing about with cars but that’s the stuff we enjoy.

Yeah pre FL 3k is between 79/81mph. I always do 70-75 on the motorway but when it comes to overtake I accelerate gently up to 80mph/3k and because I’m adding load the loud drone comes in.

Yeah thank you for your comment!

 

[TomBlueS3]

View attachment 171073 I know it doesn't help but we supply all of our products with anti-drone built in ;-)
makes you wonder why other brands don't...
Cheers
Nige

Hi Nige,

I did consider your BCS Res delete pipe in the first instance but due to the price between this and a straight bit of pipe I thought I would try the cheaper option - how wrong was I? I’ll see how I get on with the stock resonater and Cobra back box but if it’s to quiet I’ll buy a res delete from you!

Is there honestly no drone whatsoever? Just more noise? Thanks

 

[BCS Nige]

Hi Tom - no worries
Yes, no drone ;-)
valves must be coded back in, however.
Cheers

 

[AlS3BE]

Hi Tom - no worries
Yes, no drone ;-)
valves must be coded back in, however.
Cheers

Whereabouts are you guys based?

 

[Starry]

I have a scorpion de-cat and also had a de-res with an oem system. It sounded terrible, really metallic and raspy, almost like a high pitched vibration. I put the res back in place and now it sounds pretty good to my ear. No drone, but with your Cobra you will have to try some variations.

 

[TomBlueS3]

I have a scorpion de-cat and also had a de-res with an oem system. It sounded terrible, really metallic and raspy, almost like a high pitched vibration. I put the res back in place and now it sounds pretty good to my ear. No drone, but with your Cobra you will have to try some variations.

Awesome....so are you currently running a de cat with a Scorpion back box and oem res?

Well tomorrow the OEM res goes back in leaving me with a full stock exhaust apart from a Cobra back box. So I’ll see how I get on just hope it’s not to quiet.

 

[Starry]

Awesome....so are you currently running a de cat with a Scorpion back box and oem res?

Well tomorrow the OEM res goes back in leaving me with a full stock exhaust apart from a Cobra back box. So I’ll see how I get on just hope it’s not to quiet.

No mate, just scorpion de-cat down pipe with stock system. Id say a de-cat with res and cobra boxes should sound nice. I think you need the res to remove the metallic noise and make it sound a little deeper, also this will reduce the drone a fair bit.

 

[Adam14]

Hi Nige,

I did consider your BCS Res delete pipe in the first instance but due to the price between this and a straight bit of pipe I thought I would try the cheaper option - how wrong was I? I’ll see how I get on with the stock resonater and Cobra back box but if it’s to quiet I’ll buy a res delete from you!

Is there honestly no drone whatsoever? Just more noise? Thanks

I've had mine in since September and there is no drone and I do plenty of driving.

Makes the car a lot louder and sportier, couldn't live without it now.

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[Adam14]

Whereabouts are you guys based?

They're based in St Helens (near Liverpool)

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[AlS3BE]

They're based in St Helens (near Liverpool)

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A bit far for me

 

[Adam14]

A bit far for me

They ship if you want it installed by someone nearer yourself. I don't believe it's a difficult job. I drove there (3 hours) to get it done, made sense for me.

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[AlS3BE]

It will be about 3 hours each way for me too.

 

[oli356]

I did a 3 hour or something drive each way too. I couldn't be bothered to find a garage to do the work... With a ramp and a cutting tool though it looks simple enough. But otherwise need to try find a garage who is willing to do it.. And then pay them god knows how much.

I opted for the drive..

 

[BCS Nige]

Install time is 30 minutes or if you know your way round the job 15 minutes.
Fitting instruction images below ;-)
cheers
Nige

 

[Kenny_GTI]

am in the same situation just now with my exhaust. With stage 1 I just had a resonator delete in and with valves coded in it wasn’t too bad on motorway with drone and I got use to it but passengers complained!
I recently went Stage 2 with scorpion DP and had to refit OEM resonator as it sounded terrible and drone was deafening!
My issue now I find it rather quiet.... I have no overrun pops and crackles now even though it’s mapped in by APR. I get them occasionally in sport mode by nothing in manaual (S Tronic).

Now unsure what my options are for what I want! No drone, but a bit louder with the pops and crackles!?

 

[paul1975]

I have a sports cat dp with stock cat back. No drone at all just a slightly deeper note. Completely different to the res delete I did have. Based on my research before going stage 2... I believe that it is not recommended to go for a dp without the tune... guessing to do with back pressure upsetting the driveablity of a std car?

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