I don't know of any sites that are good bro..
And, I don't think you quite understand what a blow off valve is...You have to have a F.I. car for it to have a blow off valve...most of the time...a turbo car...
And most BMW's...especially e46's are not...actually i think there are only two turbo e46's around at this point..
Hope this is helpful...
:thumbup: