Anyone know how that steel pipe is fixed to the alloy inlet manifold?

Thing is, it's just where I need to put a plenum chamber, and I need to replace it with a curved pipe......... if I knew how it was fitted, I'd know how to remove it!

ive never took one out, not sure if it helps but if you can block it off you could use a grande punto thermostat instead, it has one in the housing instead of manifold.

can just about see it in this pic

That's clever, yes. Thanks.

I just realised that for this -- Cinq Tub -- application, the pipe has plenty of room. Where it a supercharger (or at least, a Rotrex one), the pipe would have to go!