There is no such thing as the Lorentz transform with non-constant velocity. By definition the Lorentz transform is a transform between inertial frames, so the velocity is constant. However, your question could be broadened to ask for arbitrary transforms, especially non inertial ones. A couple of people have mentioned the Rindler coordinates, which is the simplest such transform. Under any generic transform you can write: $$m\frac{d^2 x^{\mu}}{d\tau^2}=f^{\mu}-m\Gamma^{\mu}_{\nu\lambda}\frac{dx^{\nu}}{d\tau}\frac{dx^{\lambda}}{d\tau}$$ This is the equivalent of your expression for any coordinate system. The $\Gamma$ terms are called the Christoffel symbols and can be calculated from the metric in any coordinates of interest. For example, the Christoffel symbols are given for a rotating coordinate system using polar coordinates in section 2.1.5 here: https://arxiv.org/abs/0904.4184 They are $\Gamma^r_{tt}=-\omega^2 r$, $\Gamma^{\phi}_{tr}=\Gamma^{\phi}_{rt}=\omega/r$, $\Gamma^r_{t\phi}=\Gamma^r_{\phi t}=-\omega r$, $\Gamma^{\phi}_{r\phi}=\Gamma^{\phi}_{\phi r}=1/r$, $\Gamma^r_{\phi\phi}=-r$