I don't think it's a good idea unless you have custom headers and down pipe, if you increase the temperature inside the exhaust you increase the restriction and reduce exhaust and thus engine performance. The people that do it (race cars etc) have HUGE pipes but also have huge temperatures to contend with, in those situations it's warranted.These seems to be a LOT of heat in that one area. Has anyone tried the heat wrap?
Couldn't have put it better myself. Apart from looking messy it serves no performance purpose. Gasses after the turbo should be kept as cool as possible. Find something else to spend your time and money on.Insulation wrap on turbos is applied BEFORE the turbo, to keep the exhaust gases hot and expanded as much as possable, then no wrap is used after the turbo (unless there is a need to protect from the heat) beacuse you want the rest of the exhaust to be as cool and the gases dense (so they can move freely in the pipe). Turbins work on the VOLUME of gases passing through them, more so then the density of the gases, so keeping them expanded make the turbo spool faster and you get more out of them.
All that being said, I doubt you would notice any advantage in the Saab turbo with or without a wrap. Keeping the turbin houseing that hot creates its own problems, and a cool down time would be required to reduce the possability of oil cokeing. everything is a trade-off and I think you would trade longivity for very little if any gain by wrapping the exhaust.