Aston Martin DB9 Vanquish S rear box, I was going to modify the silencer on the DB9 to produce a better louder sound when the valves are open but not changing the sound in quiet mode, however I came across abettre option, using a Vanquish S exhaust backbox instead.
My exhaust is decatted (secondary cats removed) which makes it much louder, but then has an x-pipe which, in my opinion makes it sound better, smoother but quieter.
The Vanquish S has a number of advantages over the DB9 exhaust
- Much lighter, 13Kg instead of 25Kg
- Quad outlets, which look cool
- Cooler running, because the straight through pipe doesn’t heat up the silence
- Louder in straight through mode
![DB9 vs Vanquish Silencer](https://db9s.com/wp-content/uploads/2023/07/20230614_105353-1-scaled-e1690446190755-1024x488.jpg)
DB9/DBS Silencer system
![Aston Martin Silencer routing](https://db9s.com/wp-content/uploads/2022/04/DB9-silencer-routing.jpg)
![DB9 Muffler assembly](https://db9s.com/wp-content/uploads/2022/04/Aston-Martin-silencer-assembly.jpg)
![DB9 Backbox open](https://db9s.com/wp-content/uploads/2023/05/20230512_091832-scaled-e1684078429449-1024x555.jpg)
As can be seen even the straight through pipe has perforations to make it quieter.
Vanquish Silencer System
The Vanquish (Mk2 from 2013 – 2018) has a different system, more like the Vantage V12S system with a smaller box and with the straight pipes external to the silencer box, inside the box is a crossover system, like an H- Pipe. The Vanquish S also has an additional 2 outlets.
![Aston Martin Vanquish 2 S backbox](https://db9s.com/wp-content/uploads/2023/05/s-l1600-3-e1684754888794-1024x768.jpg)
![Aston Martin DB9 Exhaust Modification](https://db9s.com/wp-content/uploads/2023/05/s-l1600-2-e1684759212227-768x1024.jpg)
![Vanquish Box cut open](https://db9s.com/wp-content/uploads/2023/07/IMG_1110_trimmed-L.jpg)
I managed to find a Vanquish S box very cheap and originally I was going to remove the additional outlets, but after a poll on Aston Martin DIY on facebook the overwhelming response was go for quad outlets, photoshopped below to see what it would look like.
![](https://db9s.com/wp-content/uploads/2023/07/20230614_112204-1-1024x644.jpg)
![DB9S with quad exhaust outlets](https://db9s.com/wp-content/uploads/2023/07/vanquish-2-S-1-1024x644.jpg)
Installation
![DBS, DB9 rear box removed](https://db9s.com/wp-content/uploads/2023/07/20230711_091808-1-scaled-e1690903303142-1024x558.jpg)
![Vanquish S silencer in position on DBS](https://db9s.com/wp-content/uploads/2023/07/20230714_120650-scaled-e1690903616883-1024x463.jpg)
Trial fitted the Vanquish S rear box, the box is much smaller but the extra outlets touch the Battery back up sounder and are very close to the vacuum pump.
![DB9 Boot floor from underneath](https://db9s.com/wp-content/uploads/2023/07/20230713_095650-scaled-e1690903354738-1024x461.jpg)
I have found that the boot gets very hot on long trips, not great for picnics 😉 There is just a single heat shield between the silencer and the boot floor.
![DB9 Boot floor from underneath with heat shielding](https://db9s.com/wp-content/uploads/2023/07/20230713_100755-1-scaled-e1690903389231-1024x461.jpg)
I added extra heat insulation (partly done above), this combined with the fact the the louder pipes are now straight through, not heating up the rear exhaust box will keep the champagne in the boot much cooler.
![DB9 vacuum pump mounts](https://db9s.com/wp-content/uploads/2023/07/20230713_121120-scaled-e1690904680469-1024x461.jpg)
This is where the vacuum pump mounts (battery backup sounder is almost identical), it was touching the outer outlet pipe of the exhaust.
![Aston Martin Vacuum Pump bracket](https://db9s.com/wp-content/uploads/2023/07/20230713_121114-1-scaled-e1690903454746-1012x1024.jpg)
An extra bracket fabricated to move the vacuum pump, reservoir and solenoid away from the exhaust.
![Aston Martin Vacuum pump repositioned](https://db9s.com/wp-content/uploads/2023/07/20230713_121909-scaled-e1690903509711-1024x461.jpg)
![Aston Martin battery sounder repositioned](https://db9s.com/wp-content/uploads/2023/07/20230714_100400-scaled-e1690903560907-1024x461.jpg)
![Cutting out DBS diffuser](https://db9s.com/wp-content/uploads/2023/07/20230716_090850-scaled-e1690904907933-1024x541.jpg)
The scary part, starting to cut the diffuser out for the extra outlets.
![Vanquish S silencer on DBS](https://db9s.com/wp-content/uploads/2023/07/20230716_125044-scaled-e1690903812709-1024x461.jpg)
On the DBS the exhaust tip is mounted onto the rear exhaust mount, I purchased extra rear mounts to fit the extra outlets, the sides of the floor are slightly lower so the mount had to be modified to get the exhaust tips to be more level.
![](https://db9s.com/wp-content/uploads/2023/07/20230717_162855-1024x698.jpg)
![Aston Martin DB9S with Vanquish S quad exhaust](https://db9s.com/wp-content/uploads/2023/08/20230801_084011-1024x493.jpg)
Youtube Sound Clips
These do not do justice to the sound of the exhaust, it is much louder in loud mode (I have a 3 way exhaust switch), but still nice and quiet in the quieter mode.
Great post. Did you have any more photos of the inside of the standard DB9 backbox?
Interesting even the ‘straight’ pipe has perforations
Posted some mor pics in your post on Pistonheads