How Hot Do Genuine Heat Exchangers Get / Plastic Ducting?

[BrilliantBlue]

Hello, I"m wondering how hot the heater air coming out of the heat exchangers gets?

My front to rear heater tube is gone and the Y piece at the rear resembles a cheese grater.

I could more easily replace this with some kind of plastic ducting which I rekon would insulate better than the original steel stuff, but would it take the heat....?

Has anyone done this with success?

Cheers
Dave

 

[Webbaldo]

I thought of doing this and scrapped the idea as apparently it can get hot enough to melt plastic.

BUT

stainless 70mm exhaust tube on ebay is pretty cheap. I just used this, 2m length is like £20 odd, miles cheaper than the original stuff

Cant help you with the Y bit

 

[Tofufi]

I melted a tarpaulin on my rear heater ducts once...