In this paper we analyse the phenomenon of the slow passage through a transcritical bifurcation with special emphasis in the maximal delay zd(λ,ɛ) as a function of the bifurcation parameter λ and the singular parameter ɛ. We quantify the maximal delay by constructing a piecewise linear (PWL) transcritical minimal model and studying the dynamics near the slow-manifolds. Our findings encompass all potential maximum delay behaviours within the range of parameters, allowing us to identify: (i) the trivial scenario where the maximal delay tends to zero with the singular parameter; (ii) the singular scenario where zd(λ,ɛ) is not bounded, and also (iii) the transitional scenario where the maximal delay tends to a positive finite value as the singular parameter goes to zero. Moreover, building upon the concepts by Vidal and Françoise (2012), we construct a PWL system combining symmetrically two transcritical minimal models in such a way it shows periodic behaviour. As the parameter λ changes, the system presents a non-bounded canard explosion leading to an enhanced delay phenomenon at the critical value. Our understanding of the maximal delay zd(λ,ɛ) of a single normal form, allows us to determine both, the amplitude of the canard cycles and, in the enhanced delay case, the increase of the amplitude for each passage. •Exploration of the slow passage phenomenon in transcritical bifurcations through piecewise linear (PWL) differential systems.•Identification of qualitatively different maximal delay behaviours as a function of the parameters.•Construction of a suitable PWL system exhibiting an unbounded canard explosion and enhanced delay.