Bob,

BTW, I am going with the ES40G in the Extra. There's plenty of room in the tunnel for this. The internals are identical to the 30G I have on hand, but I need the 30G for my pattern plane. Going to learn something either way.

I am staying with the fiberglass tape coupler for now. But I am very interested in what you find out with the turbo hose. I've drilled and tapped the pipe stem and header for a 4-40 button head screw as Ed Skorepa suggested, which will work like a barb and hold the coupler material better. I am using the tape alone with stainless steel wire ties. It needs cooling air over it to keep the silicone adhesive cool enough so it can provide a good seal and not melt.