i recently bought an audi A3 1.8 quattro.. lovely car but seriously lacking in power( 150bhp version).

this week i fir my new wheels and tires and a new air filter from K&N .. wanted to fit a dump valve but have been advised not to next month the car gets chipped and hopefully a new exhuast system to go with it.. but i have heard there is an audi part ( thatcan only be bought at audi or saab)to be used instead of any dump valve, bosch ticker or something? any one know?`? have heard a car with it.-. with out moving he revs it and they it sounds a lot better. anyone know what i mean ? many thanks in advance for help that may come..