There’s a fine art to driving a manual transmission, especially in a high-performance car. The smoothest shifts happen when engine speed matches the gear you’ve selected.
But when you push in the clutch pedal, which disconnects the engine from the transmission, the engine speed drops. When you take your foot off the clutch to reconnect them, the speed difference can make the car buck and lurch. This sets your passengers’ heads bobbing, and strains the car’s components.
Race drivers solve it with a trick called heel-toe downshifting. For the rest of us, Nissan invented SynchroRev Match, available on the new 370Z coupe and roadster.
“The benefit is that it allows for a smoother gear change, and allows the driver to concentrate on steering and braking,” says Sean Chen, manager of product planning at Nissan Canada. “It smoothes out the ride. If you’ve made a sloppy gear change, you know what that transition is like. SynchroRev Match ensures a perfect gear change every time.”
In heel-toe, the driver keeps his foot on the brake, but rolls it to the side, jabbing or “blipping” the throttle while he moves the shifter. This raises the engine speed for a smooth shift, but it’s a complicated manoeuvre and, as Chen points out, you should be learning it on a closed course, rather than on public roads, a luxury many drivers don’t have.
Rev-matching is common on many performance cars with automatic transmissions, but Nissan is the first to develop it for a stick shift. It uses three sensors: one on the clutch pedal; one on the gearshift lever, to detect its movement; and an input speed sensor. Depressing the clutch activates the system, which then determines the direction you’re moving the shifter. An engine control module calculates the target engine speed and sends the information to the electronic throttle.
It all happens so quickly that if you skip a gear, the system still has enough time to determine the gear you’ve selected, and blip the throttle to match. It also detects and smoothes out upshifts as well. Those who prefer to heel-toe themselves can simply turn it off.
“The mechanicals are the same as on any other vehicle,” Chen says. “SynchroRev Match sounds great and takes the lumpiness out of sloppy gear changes. We’ve read all about proper heel-toe, but most people haven’t had the chance to be exposed to it properly. We simply provide you with choice.”