No-lift shifting looks as if a easy idea. As an alternative of lifting off the throttle whereas shifting a handbook transmission, you simply preserve your proper foot planted. However there’s extra to it than that, particularly with turbocharged engines, as detailed on this video from Engineering Defined.

A handful of manufacturing vehicles have provided no-lift shifting options from the manufacturing facility, starting from the Chevrolet Cobalt SS to the present Cadillac CT4-V Blackwing.

Within the Cadillac, there is a twin-turbocharged 3.6-liter V-6, a sort of engine the place a no-lift shift will be significantly useful for sustaining enhance. Nonetheless, if the automobile is not arrange for it, you additionally danger harm to the transmission. Holding your foot on the throttle raises engine velocity, placing numerous further load on the clutch when its time to re-engage.

One option to preserve enhance with out permitting the engine and transmission speeds to get out of sync is by retarding the ignition. This permits for elevated exhaust strain to maintain the turbo spooled up with out spinning the crankshaft quicker. A gas cutoff ensures the engine does not rev previous its redline, whereas the turbo’s waste gate is saved closed to harness the added strain being generated. 

Cadillac’s no-lift shift system additionally retains the consumption bypass valve closed. This might usually open when off throttle to forestall extra air strain from build up within the consumption and getting pushed again into the turbocharger, a phenomenon referred to as “turbo surge.”

Within the CT4-V Blackwing, each the throttle and bypass valves keep open whereas no-lift shifting, guaranteeing there’s loads of enhance able to go when the clutch re-engages.

The Cadillac CT5-V Blackwing additionally has no-lift shifting, however that doubtless produces much less profit with the bigger sedan’s supercharged 6.2-liter V-8 as a result of there aren’t any turbos to maintain spooled up. But it surely does imply you may preserve your proper foot down whereas working via the vehicles, which is cool it doesn’t matter what engine you will have.