anyone know how to install? with pictures? thanks

I wouldn't bother, I reckon they're a con.

alot of folk just want them for the noise tho!

There are soda syphons that will do that. the way I see it, why waste all that lovely compressed air?

Sugest - spend the money on beer, far better VFM.

Relativly easy. Locate the recirculating one on the car. Detach the vaccum pipe on the top of the valve and the two large jubilee clips which are located on the bottom and the side of the valve. Remove the whole valve from the car.
Get a bung from an accessory shop and fit it in the hole nearest the airbox. tighten with a Jubilee clip you loosened. Push your shiny new dump valve onto the other hole, tighten (really tight) the second jubilee clip and then put the vaccume hose you removed from the top of the recirculating job on the top of the valve.
Go for a spin and admire the cool noises eminating from under the bonnet.
:cool:
astraboy.