Unlock serious performance out of your Audi S3 8V with the BCS Powervalve Downpipe, available in 76mm and 90mm configurations to match your build and power goals. The 76mm version is ideal for lightly to moderately tuned setups (up to stg 2), capable of supporting up to 460bhp. For those pushing higher power levels, the 90mm variant is designed to comfortably support 500+ bhp, making it the go-to choice for hybrid turbo upgrades and aggressive builds.  

Both our Sports cats have a 40gram loaded coating to ensure longevity, with a oversized 5" design to maximise flow whilst still being emissions compliant. The 200cell is perfect for setups up to around 440–450bhp, while the 100cell cat  offers a greater flow for big power applications whilst still remaining MOT compliant.  Both configurations dramatically reduce backpressure, improve turbo spool, and enhance throttle response—all while delivering a sporty, more aggressive exhaust note under load without compromising on drivability. Designed for seamless fitment and long-term reliability, this is the ideal downpipe upgrade whether you’re chasing fast road performance or preparing for serious track use.

We supply a connecting pipe and adapter for stock or aftermarket systems to allow you to connect back up with a minimal fuss. If you decide to upgrade to the full turbo-back system at a later stage then the connecting pipe simply swaps out again to allow the installation with a minimum of fuss.

In order to install the downpipe on the 4wd MQB platform cars, the front subframe will need to be lowered to remove the OEM downpipe.

The fitting time for this product is @ 3-4 hours 

The Data supporting the product is shown below

  Original Equipment Cat 

  Description                         Limits                          Actual Value

    Fast Idle Test

• Engine Speed               2500 - 3000 rpm                 
• Co                                  < 0.20%                            0.00%  PASS              
• HC                                  < 200 ppm                       1ppm   PASS
• Lambda                         0.97 - 1.03                        1ppm   PASS

   Natural Idle Test

• Engine Speed              450 - 1500 rpm                 
• Co                                  < 0.30%                            0.00%  PASS              

BCS Powervalve 100 Cell Cat 

 Fast Idle Test

• Engine Speed               2500 - 3000 rpm                 
• Co                                  < 0.20%                            0.00%  PASS              
• HC                                  < 200 ppm                       4ppm   PASS
• Lambda                         0.97 - 1.03                        1ppm   PASS

   Natural Idle Test

• Engine Speed              450 - 1500 rpm                 
• Co                                  < 0.30%                            0.00%  PASS