Hola,
La web de Wunderlich parece traducida automaticamente y sin supervision humana.
Es mejor ir a una version inglesa o alemana (la que mas controlemos) y leer alli la descripcion. Incluso no entendiendo el idioma, podemos encontrar mejores opciones de traduccion.
"Many of the new BMW models are fitted with a flapper valve in the exhaust system.
The valve is a device that is intended to reduce noise emissions and it is also claimed that torque output is increased but our testing has shown that this is not necessarily the case. By installing the Power Tube the valve is removed and the motor can breathe freely in all rev ranges.
In addition the exhaust sound is increased but not to obnoxious levels. The engine will benefit from full performance potential throughout the entire rev range.
Features and Benefits:
· Improved sound.
· High grade stainless steel.
· Full power potential throughout.
· Supplied with everything needed to install.
· Optically discreet, hardly noticeable.
"
Basicamente, que se sustituye una valvula del escape por este tubo para que respire mejor. En teoria con la valvula da mas potencia, pero a la practica solo la ponen para contener el ruido en la ITV.
Nótese que no está permitido su uso por la via publica. Vamos, que no pasas ITV con esto, pero en un circuito debe tirar un poco mas.
Saludos
janSolo