How does synchrorev work

With the V6, the synchro rev match helps alot, and without it, it is less forgiving when you down shift. Originally Posted by kailua. Originally Posted by Nikon FM. I really don't think "it" matters, but "it" sure is dang fun.

Originally Posted by semtex. That's due to the heavy dual-mass flywheel. Has nothing to with 6 vs. Heavy flywheels have more inertia, which means it takes more energy to change the revs in either direction. When you downshift, if you don't blip the throttle in advance either manually or via SRM , the revs will climb as soon as you re-engage the clutch as a lower gear revs higher than the preceding higher one.

In other words, as soon as you re-engage the clutch, the clutch will 'grab' the flywheel and force the rpms up. Because a high-mass flywheel has more inertia and it takes more energy for the revs to climb, it's jerkier. This would be true regardless of how many cylinders the engine has. And it's also why they offer lightweight flywheels on the aftermarket one of the most popular for this car is from Jim Wolf Technology. Actually, a heavier flywheel isn't so good for upshifts either, because with a heavier flywheel, the rpms don't drop as quickly in between gears.

The higher inertia keeps the rpms spinning for a longer time when you disengage the clutch, but when you shift into a higher gear and re-engage the clutch, the new gear is going to start off at a lower rpm, so upshifts can be jerky as well, especially if you're shifting very quickly. The benefits of a heavier flywheel are less noise, and easier launches. My understanding is that Nissan chose a heavy flywheel specifically due to noise concerns.

They did this with the and G35 as well, btw -- this isn't a new deal specific to the and G And I believe it, because in my I had a JWT lightweight flywheel and that thing sounded dreadful. To the untrained ear, it sounded like the car had a mechanical problem, so installing a lightweight flywheel from the factory would probably have hurt sales as the average consumer would be turned off by the sound.

Regarding launches off the line, a lightweight flywheel is much easier to stall, precisely because it has lower rotational inertia. Think of it this way. The flywheel is attached to the crank and is always spinning. When you engage the clutch from a standstill, you are essentially connecting the spinning flywheel to the stationary crankshaft. Now, at that moment, you're mating two opposing forces together.

By virtue of inertia, the flywheel wants to continue spinning at whatever rpm level, and the crankshaft wants stay still. Which component will win? Well, the crankshaft will win if you don't give it enough gas.

With a heavier flywheel, the flywheel has more inertia, which means you have to give it less gas in order to offset the inertia of the stationary crankshaft, which in turn means it's easier to launch without stalling. Indeed, this same physics explains why your engine revs quicker all throughout the rpm band with a lighter flywheel. Remember that the flywheel is connected to the engine crank. When you give your engine gas, the crank spins the flywheel faster. The less mass the flywheel has, the more it's willing to spin faster i.

Make sense? Sorry, I know that was a little long-winded, but I wanted to be as clear as possible. The 4 cyl. They were probably a little easier to stall at launch too. I had an S that came with a light flywheel.

It was really smooth to shift up and down, but it'd stall easily too from a launch. If I recall correctly, I had to rev it to about rpm to launch off the line smoothly. I don't have to rev anywhere near that high with the Z. Last edited by semtex; at PM. Ah, that explains it, the speed 3 is super easy to stall out. If you even think about letting out the clutch a mm without giving it some gas, it will stall.

The STI not as much. I almost bought an auto z until I drove the 6spd and in comparison to the other vehicles, it is so much easier to shift and drive on a daily basis, in traffic, etc. It's a pretty common grip about the speed3. Perhaps Mazda's idea of "ideal" and the consumers' idea is different. Pressing in the clutch pedal triggers the system, and when it detects movement in the shift lever, the engine control unit calculates the target engine speed and adjusts the electronic throttle accordingly.

The gearshift sensors monitor gear position as well as side-to-side shifter movement and are sensitive enough that you can hold down the clutch pedal and watch the revs jump precisely to the right rpm if you merely hint at moving the shift lever to a lower gear.

Plus, unlike stability control, SynchroRev Match enhances the driving experience instead of diluting it, removing pre-corner anxiety and allowing you to focus on braking and turn-in. Some might see SRM as another step toward the fully computer-driven car. New Cars. Buyer's Guide. Type keyword s to search. Today's Top Stories.