Fuel vapour breather?

[NSharpley]

Is that what this is?

Do I really need it in a track car?

[NSharpley]

Thanks.

Most of the catch cans I've looked at have an "in" and an "out".

Does the "out" need to feed back into the air box?  It seems redundant if there's a breather on top of the catch can.

[Fetta GTV]

That pipe is the line from the carbon canister from the fuel tank breather system.