I have a decent knowledge of dump valves - owning a Punto Turbo and all (Collins twin piston in mine) but yesterday a Cav turbo drove past me and (like you do) dumped right at the side of me. The dump sound was a high pitched and long drawn out dump, I really like that kind of dumping sound. My Collins twin piston is really loud and much deeper than the one I heard on the Cav. Anyone any idea which dump valve this Cav could have been running? It sounds alot like the one in The Fast and the Furious on the green car at the begining.
I really wanna know so's I can get one for my C20LET Corsa.