991 GT3 - Recommendation for bolt on silencer

[adamGT3]

Hi all,

I get black flagged on track days on my 991.1 GT3 due to the drive by noise from my exhaust. I have tried up-shifting etc. but still managed to fail mainly as I have sharkwerks bypass so I need a bolt-on silencer to reduce the noise when I do track days. I don't do many otherwise I would have done the obvious and put back the standard exhaust but prefer the sharkwerks. I came across the Decibel Slayer Bolt On from Demon Tweeks, has anyone tried these before if not can you recommend a good bolt on silencer for the GT3?

Thanks

[Flat0ut]

I am in the same position as you - just fitted a Sharkwerks bypass and disconnected the valves - it sounds amazing now but I have previously had drive by black flags at Bedford even with standard exhaust although the static noise test was okay as the 991 will only rev to 4500 revs stationary so it gets through.

I am now after a lot of research about to buy one of these and will reconnect the valves before track days as it takes 2 mins:

https://www.actproducts.co.uk/product/si06-porsche...

Not the prettiest solution but it is quite easy to bolt on and off. The key is also the tips are facing downwards which should help with drive by meters.

As a matter of interest - have you had an issues with the static noise testing with the Sharkwerks fitted? Are your valves connected and which tracks are you referring too?

[nxi20]

This is a neater option, albeit a bit pricier:

https://uber9s.com/product/gt3-trackday-silencer/

[Flat0ut]

nxi20 said:

This is a neater option, albeit a bit pricier:

https://uber9s.com/product/gt3-trackday-silencer/

Yes saw that and its definitely prettier but i am not convinced it can offer as much noise reduction as the silencers look small. I can't find any feedback on this silencer on any of the forums but if anyone has used it, it would be good to know...

[Scott Parker]

I'm in the same boat really and could do with knocking off a couple of DB for certain track days for my RS. I have a Sharkwerks form my 991 GT3 but have not bothered fitting it as the .2 RS is already quite loud and titanium too.

Both those options don't look too great to be honest and its almost like you need a hybrid version of the 2. The 1st one doesn't look like it will fit over the pipes plus not sure about having 6kg hanging off of the tailpipe welds and the 2nd one doesn't look like it will do much

[911Thrasher]

not going to help, but take it to a real track like Spa...the GT3 and RS excel there and no need for whatever noise reduction systems.
Spa is their natural habitat - Bedford is a joke

[TDT]

I reckon the Uber9 solution looks best out of what has been recommended so far. -

Another option for even more money i suspect.... https://www.jzmporsche.com/product/akrapovic-db-so... ... apparently it fits with standard system/bolt pattern?

Edited by TDT on Monday 1st October 16:57

[Scott Parker]

TDT said:

I reckon the Uber9 solution looks best out of what has been recommended so far. -

Another option for even more money i suspect.... https://www.jzmporsche.com/product/akrapovic-db-so... ... apparently it fits with standard system/bolt pattern?

Edited by TDT on Monday 1st October 16:57

Last time I checked that Akra was about £1200

[TDT]

Scott Parker said:

TDT said:

I reckon the Uber9 solution looks best out of what has been recommended so far. -

Another option for even more money i suspect.... https://www.jzmporsche.com/product/akrapovic-db-so... ... apparently it fits with standard system/bolt pattern?

Edited by TDT on Monday 1st October 16:57

Last time I checked that Akra was about £1200

Like i said...even more expensive

[adamGT3]

Any thoughts on this

https://www.demon-tweeks.com/uk/decibel-slayer-bol...

I saw something similar on a 997 GT3

[adamGT3]

Flat0ut said:

I am in the same position as you - just fitted a Sharkwerks bypass and disconnected the valves - it sounds amazing now but I have previously had drive by black flags at Bedford even with standard exhaust although the static noise test was okay as the 991 will only rev to 4500 revs stationary so it gets through.

I am now after a lot of research about to buy one of these and will reconnect the valves before track days as it takes 2 mins:

https://www.actproducts.co.uk/product/si06-porsche...

Not the prettiest solution but it is quite easy to bolt on and off. The key is also the tips are facing downwards which should help with drive by meters.

As a matter of interest - have you had an issues with the static noise testing with the Sharkwerks fitted? Are your valves connected and which tracks are you referring too?

My valves are connected and i've had no issues passing static noise tests as it doesn't allow you to rev over 4000 and the noise kicks in around 3750. I did Brands Hatch in August and doing Goodwood next Saturday.

[adamGT3]

911Thrasher said:

not going to help, but take it to a real track like Spa...the GT3 and RS excel there and no need for whatever noise reduction systems.
Spa is their natural habitat - Bedford is a joke

Agreed, defo on my to do list. All this noise reduction is a headache ....