Do You Need an Intercooler for a Turbo
A turbocharger compresses intake air, and that compression always adds heat. The question of whether you need an intercooler for a turbo is really a question about how much heat your engine can tolerate before power and safety suffer. Many turbocharged vehicles include a charge-air cooler, but the answer is not universal because some low-pressure or factory systems rely on short routing, rich fueling, or modest boost pressure instead.
Essential answer
Most turbocharged engines should run an intercooler, though a turbo can physically operate without one at very low boost pressure. The cooler removes heat from the air leaving the compressor outlet. Without it, charge-air temperature rises quickly, making the intake charge less dense and raising the chance of detonation. Whether the vehicle requires one depends on the boost level, intake plumbing length, fuel control, and how the manufacturer manages heat.
An intercooler is not strictly a mandatory component like an oil feed line, but skipping it is usually a poor trade. A turbo does not exist to make hot air; it exists to pack more oxygen into the cylinder. Cooling the charge supports that goal. When heat is not controlled, the engine may pull timing or add fuel as a protective response, and both changes can erase the gain the turbo was meant to provide. The central reason to use an intercooler is therefore consistency, not mere power potential.