Can I turn a pie recipe into a tart recipe?

Are you trying to turn a pie into a tart or cook a pie in a tart tin?

If the former, then not being encased in pastry could affect the cooking of the filling. Depending on what kind of pie it is and if the filling is precooked or not.

If the latter, then all it is a shallower dish. The filling may take less time to cook but the pastry might need the same as the initial recipe , as its surface area is likely to be roughly the same.

Typically a tart pan is shallower than a pie pan so two things will be affected by taking a pie recipe and baking it in a tart pan: You'll probably have more crust dough than you need and you may have too much filling