It depends. Some stimmed pre workouts do not have high enough doses of the pump inducing ingredients. For example, HyperMax XT has perfect amount of agmatine and L-Citrulline for awesome pumps while providing users with laser like focus and energy. Some products, such as Mesomorph, provide awesome energy and focus, but lack the amount of pump inducing ingredients. If that is the case, you could stack that non stim product with a simmed one such as High Volume, VasoMax, or Kraken Pump.