Why does my cake shrink after I took out of the oven?

You know, I have the same problem when I make a Duncan Hines chocolate cake. It's only the chocolate cake that I have so much shrinkage. The white cake doesn't shrink nearly as much so I'm thinking it has something to do with the ingredients in the cake mix. Just like you, the cake rises great, but as it cools, it shrivels up and looks yucky. I don't know what a turbo boiler is, so I can't help you with that, but I have an electric oven, the temperature is fine and if I have a dark, coated pan, I just reduce the heat by 25 degrees and cook for a couple minutes less. It's frustrating because I love chocolate cake!!

There will be some shrinkage when you take it out of the oven as it cools off and hot air escapes from it.

If a cake falls in the middle, its because its been shook in some way, like slamming the oven door and moving the pan around inside the oven. Be real careful when moving the cake out of the oven to where its going to cool. Treat it like its a baby. Handle with care.

I'd bake the cake in the center of the oven on the middle of the oven rack for best results. You don't broil cakes, hehehehe.

You take it out of the oven as soon as its done. If you leave it in there it will keep cooking as the oven is still hot.

I'd like to see a photo of this shrinking cake to see what you mean and how much its shrinked. Interesting.

I dont think the oven has to do anything about it. Maybe you over mixed it thats why it didnt rise.

maybe you got your oven too high and the center isn't as done as it should be?