No-lift shifting may appear straightforward at first glance – keeping your foot on the throttle while shifting a manual transmission. However, there’s more to it than meets the eye, particularly when it comes to turbocharged engines, as explained in this Engineering Explained video.
Several production cars come equipped with no-lift shifting features right from the factory, spanning from the Chevrolet Cobalt SS to the current Cadillac CT4-V Blackwing.
In the Cadillac CT4-V Blackwing, which boasts a twin-turbocharged 3.6-liter V-6 engine, no-lift shifting can be particularly advantageous for maintaining boost. Yet, without proper setup, it can potentially damage the transmission. Keeping your foot firmly on the throttle increases engine speed, subjecting the clutch to extra strain when re-engaging.
To maintain boost without causing engine and transmission speed discrepancies, one technique involves retarding the ignition. This allows for increased exhaust pressure to keep the turbo spooled up without accelerating the crankshaft. A fuel cutoff prevents the engine from revving beyond its redline, while the turbo’s waste gate remains closed to harness the added pressure.
In Cadillac’s no-lift shift system, the intake bypass valve remains shut. Ordinarily, it opens when off the throttle to prevent excess air pressure from building up in the intake and being pushed back into the turbocharger, a phenomenon known as “turbo surge.”
In the CT4-V Blackwing, both the throttle and bypass valves stay open during no-lift shifting, ensuring an ample supply of boost when the clutch re-engages.
Although the Cadillac CT5-V Blackwing also features no-lift shifting, its benefits may be less pronounced due to the larger sedan’s supercharged 6.2-liter V-8, as there are no turbos to maintain. Nevertheless, it still allows you to keep your right foot planted while navigating the gears, which is undeniably cool regardless of your engine choice.
