Dump Valve with whistling noise similar to WRC

Hi,

Anyone knows if there is in the market any dump valve capable of doing the whistling noise similar to the actual WRC.

Instead of the "tsssss" noise the WRC sound like an "i i i i" noise.

In this video the sound i'm referring to is easily perceptible especially in the old Focus WRC fromt Sttobart team.

http://www.youtube.com/watch?v=6wAT3rW3H30

Thks

The hks sequential is very close when matched with a hardpipe 8)

[Tuppy]

as above whooshes sounded very similar 8)

Thks...

What's the best online shop to buy it?

Any idea?

Thks once again

They do show up new on ebay for a LOT less than RRP. I've seen them on there for £180 before now 8)