flanges?

just out of curiousity. what is the purpose/benefit of a flange on the up-pipe/downpipe? i see them for sale but i haven't seen anything that says you have to have one on your downpipe or uppipe. what is the purpose of these things. thanks.

uh....unless you want your turbo welded to a pipe, which i'm not even sure is possible, it'd be best to use flanges...if you see just the flange for sale, it's more than likely for a turbo that won;t just bolt up to the factory piping, so custom pipe fitting would be necessary.

example....a t4 turbo on a wrx. Take the uppipe, cut off the subaru style flange that bolts to the turbo. Take the T4 style flange, weld it onto the pipe. Now the big t4 turbo can be bolted to your car no problem...

that's more what i was asking...why flanges were for sale by themselves. thanks man.