pros& cons to exhaust wrapping turbo manifold?

[TRDmod]

but just curious, just want to throw this in.

the down pipe gasses move so fast that it probably doesnt have even time to lose 1% of its heat. the gas is moving so fast that it wotn have time to radiate through the steel to cool down anyways. i can understand with the manifold that the heat will escape rapidly and make the whole bay hot, i have had personal experience from this and the manifold cracked.

first my problem was i heat wrapped it, then when it was red hot, little bits of water from the bonnet scoop dripped onto it, the heat wrap absorbed the water and cracked the manifold (u know very hot and very cld) not a good mix. after fixing that, its never really the same again, then i took heat wrap off after sealing the bonnet. this worked for awhile untill i worked it hard on the track, then after it got dam hot, cracked again, theory was whcih makes sence, after i opened teh bonnet to check everything, it was really really hot, cold air hits it directly and that could make it crack too...

now im getting new ones done. the bonnet is sealed competely of water drips, i am going to heat wrap it and use slightly thicker pipes and bigger diameter too, not too much though. hope this time i wont get any problems.

also when you weld the maniflld and smooth out the outside of it, the welds strength can sometimes be comprimised . so i this time chose not to make it look nice, i mean i want it ugly and heatwrapped to withstange 16 psi of constant thrashing on the track.

keep in mind, you might have to reinforce the bottom of your manifold too, the weight of the turbo and the downpipe pulling on it can also stretch the metal in time. remember heat soften and expands metal. this can make your turbo manifold sag and weaken certain spots.... leading to a crack

[TRDmod]

as for the thermos theory, fully agree but one thing to add on my side.

you dont want your manifold to cool down quickly right cos that can cause cracks and that is bad. if you heat wrap it, it will cool down gradually, so this will in theory avoid sudden changes in temps. turbo timer leaving the car idling should kill excess heat from them and when it turns off, leaving your manifold in a ok temp to start cooling down.