The Powervalve road legal 100/200 cell cat is the ideal hardware upgrade when considering a power increase on the I4 twin-scroll turbo (M 133 DE 20 AL) engine. In addition, you will notice an audible uplift in the sound, producing a nice sporty tone in the vehicle under acceleration.

The Powervalve 100mm into 90mm downpipe and 100/200 cell cat comes with a connecting pipe (which replaces the stock front over axle pipe and flexible decoupler) to allow you to connect to the OEM cat-back system with the minimum of fuss.

The background

The 100mm downpipe and huge 150mm 100/200 cell road-legal sports cat represent the ultimate in terms of exhaust performance.

After a thorough assessment of the OEM design, a stringent development program was undertaken, resulting in a unit manufactured completely from 304-grade stainless steel.

Crucially, the tube specification increased from the stock 70,0mm diameter to 100.0mm, where it continues into the cat exiting from there with a diameter of 90.0mm.

The rationale behind this is to rapidly facilitate gas expansion, which dramatically reduces pressure behind the turbo.

The oversized cat allows for a flow ratio in excess of 100.0mm to enable maximum power to be achieved whilst remaining road legal and MOT compliant (so don't get talked into a cat delete pipe).

Again, with total performance in mind, the design can be complemented with our 1200-degree rated titanium thermal wrap, or for an even greater thermal benefit the turbo black ceramic coating, to maintain the highest possible gas temperature and lowest radiated heat signature to promote increased power and under bonnet temperature.

With all of the above features, this unit is guaranteed to provide all of the necessary means for engine tuners to achieve the maximum potential for the M133 engine, along with a superb uplift in sound.

If you decide to upgrade to the full turbo-back system at a later stage then the installation is made possible with a minimum of fuss.

The dimensions employed on our unique cat will allow a gas flow equivalent to a cat delete pipe 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              

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     

The primary use for the Powervalve 100/200 cell cat is a public road or track.

As with virtually all of the turbo-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 twin OEM cats. However, by opting for our unique downpipe and high flow cat which has a pipe configuration of 100mm into 90mm, the power potential will massively increase, firstly with an initial 22bhp kinetic, and then once mapped all the way up to a stage 3 and beyond.

The fitting time for this product is 4 hours 

The image below shows the original downpipe and cat alongside the Powervalve variant, which is supplied with the front over-axle pipe.

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