Turbos get hot. No two ways about it. They get hot enough to make paint bubble and melt up to 25cms away. But this might have been due to some hard driving, because I'd also sent my old cat convertor into meltdown..

But on Garrett turbos, the water line is only quite small, why not use the heater hoses?

There would only be a couple of people on this site with LPG experience. I'm not one of them.