The BCS Valveless system is our acoustically tuned, dual tone Turbo back system for the Seat Leon Cupra ST 4 Drive GPF Model, providing you with the maximum possible full-time audible thrill from your Cupra. The system has a greater audible volume than the cat back offering, however, with careful design and development we have created a system that ensures that any unwanted in-car frequencies are removed, leaving you with a perfect drone-free experience, together with our characterful pop and burble, free-revving sound. 

The BCS Turbo Back system was developed to be a true valveless dual tone exhaust, through extensive research and development we were able to incorporate acoustic tuning into our system to retain the subtlety of cruising and under low load whilst offering the aggressive, characterful note when accelerating and under high load. Produced in 3 variants a Wrc, Sport & Prestige sound profile, tailored options depending on desired exhaust note. Our Wrc variant is our loudest variant engineered for a motorsport inspired tone when accelerating and under high load but remains subtle whilst cruising and under load low. Our Sport variant is our mid range sound profile, giving you the best of both worlds, it's still got the motorsport inspired raw under high load as well as the discreetness of the prestige system when driving sedately. Our Prestige variant is our quietest system designed for those wanting an OEM+ note, a discreet growl turning heads when accelerating paired with a stock sound when cruising.    

This System comes with a Downpipe size option depending on the desired BHP; 76mm (up to 400 bhp) or 90mm (400 bhp+) 

The 90.0mm collector and ceramic coated surface on our unique cat provide unrivalled gas flow whilst remaining completely MOT and road legal.

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     

As with virtually all of the TSi-engined vehicles, there is very little performance gain to be had from the cat-back system on its own, due to the incredibly restrictive downpipe and OEM cat. However, by opting for our unique downpipe and high flow cat the power potential will massively increase, firstly with an initial 22bhp kinetic, and then once mapped all the way up to stage 3 the TSi 2.0 MQB Engine can achieve in excess of 600 bhp with our full turbo-back system and 100 Cell sports cat.