Factory turbos (not available in the US) are mounted on a turbo manifold. The 450's have the exhaust snail incorporated into the manifold. After market turbos for the smart use the stock manifold and a short pipe the turbo to position it better. Ask BARNEY O or jetfuel. There are a few other's on the forum. Google search is your friend.Ok so I'm guessing then that smart turbos aren't using an exhaust turbo manifold but are mounting the turbo in the exhaust pipe. I had forgot about that type of application. I had a Nissan Sentra with a turbo but I just used the JDM manifold and turbo. I was looking at the kits from Speedforceracing.