throttleless

— The next logical step in valve timing flexibility and control are fully variable mechanical systems like the BMW Valvetronic system [7], which gives increased flexibility over valve timing, duration and allows, for the first time, the ability to achieve throttleless load control with a mechanical system. Shown in Figure 14, is an example of an early inlet valve closing strategy that allows throttleless load control. […] Throttleless operation has also been shown by Law et al [5] by replacing fresh charge with trapped exhaust gasses and achieving stable combustion with over 70% exhaust gas by two valve strategies, of either early exhaust valve closing and late intake valve opening or a strategy of double exhaust valve opening.