MikeNT256

Just curious if anyone can explain Nissan's lil "5 Speed Automatic with Manual Mode" which includes the "Downshift Rev Matching Technology?" According to Infiniti's website:

Can anyone explain how this works exactly? And what advantages it has? If I do get the chance to purchase a new vehicle, I may end up choosing Automatic over Manual due to my inexperience with a manual and I don't want to deal with the hassle of it in my new job position (lots of driving)

350ed

iTrader: (17)

Well, the description you posted says it all really: "which automatically opens the throttle when downshifting to match the rpm, resulting in smoother gear changes"
Basically it blips the throttle to bring up the revs inbetween changing gears to bring the engine speed up to the tranmission speed thus creating smoother gear changes.
I haven't driven a auto Z or G so I can't say how rough the shifts are.

drift350

when downshifting manually, the vehicle will "jerk" if you let off the clutch while the engine speed and transmission rotation speed differ... forcing the clutch to "slip", resulting in the jerking.

by rev matching, the engine speed is brought up to the level the engine would be at if it were already in that lower gear with the transmission spinning at it's current rate, resulting in a smooth shift.

MikeNT256

Ohhh so is it automatic then? The computer already does it for you? I thought maybe it left it in neutral for a quick second between downshifts so you can manually blip the throttle which would be amazing!

Are there even any 2005 Owners on here yet?

sq40

iTrader: (4)

Is this new For '05, I have a 04.5 ZR with Auto and It is Smooth on the Down Shift with the Throttle to the Floor.

Now, If you let off the throttle then shift, you do get a bit of a jerk.

MikeNT256

Its supposed to be a new technology for the 2005's

Aggro_Al

The new auto rev-matching feature is new for 2005 5AT. From previous threads, they say that it does make shifting smoother in manual mode but it makes shifting much slower and there is now way to override it.

My opinion is that it's a downgrade and that there isn't any signifcant advantage and may even hamper performance. The pre-MY05 5AT already uses rev-matching in auto mode and it is way faster than any human can shift. If you want to auto rev-match the downshifts just move the lever over to auto mode and let the computer do it. In the pre-MY05 5AT, if you were in manual mode and you wanted to rev-match you had to do it yourself. I would suspect that auto rev-match might be helpful in smoothing the 5-4 shift and in some situations it might even make the 4-3 shift smoother because 5th and 4th gear are fully-locked gears but I wouldn't want the slower shifting speed. When the torque converter is unlocked the driveshaft and engine can spin at different speeds. There is no need to rev-match. I would think that you would also lose one of the advantages of having a torque converter. If the impeller and turbine in the torque converter aren't allowed to spin at different speeds they won't create the vortex flow necessary to do torque multiplication.

Let's hear from the people that have the MY05 5AT and have put it through its paces.

capnfrantic

I like the feature, I also feel the car can be made to shift better in a haul as* thru the gears situation. But then again I havent' driven any older models. Like Mike I wanted ease of driving. I don't feel like I left alot on the table going this route. JMO

G Spot

I know it 's new for '05 G's, not sure about the Z's. The auto stick if fun if you are not familiar w/ manuals. From what I read, you would actually benefit from the Auto stick. It kinda does the Heel-Toe downshift for you automaticallly.

I've test driven the '05 auto stick G. You should try it, it's a lot of fun, especially when the dealer isn't with you. It rev matches really well. I even though about buying it over the 6-spd. But there's something about the manual, that well, once you learn how to drive it, there is no other substitute. The auto stick would be the closest thing.

Go test drive one and you'll see/feel what I'm talking about.

G

Aggro_Al

You can do this in the pre-MY05 5AT but you have to have your timing just perfect and you have to be really fast. It's not easy. It is easier to just switch to auto mode and let the computer do it then switch back to manual mode. Downshifts in the pre-MY05 5AT in manual mode are fairly smooth. You probably would only notice smoother shifting if you were aggressively shifting. If I were driving aggressively I would take faster shifting over smoother shifting.

If you have a car with a torque converter, there are several times when you don't want to rev-match because when the impeller and turbine are spinning at different speeds the transmission can create more torque than the engine is putting out. Rev-matching an unlocked torque converter wouldn't matter because, unlike the 6MT, the impeller and turbine are not mechanically connected together and they are free to slip or stall. Rev-matching is not necessary to create a smooth shift, it's built into the design of the torque converter. In the 6MT, since all the gears are mechanically connected with friction plates, you need to rev-match or use the synchromesher to get a smooth shift in every gear.

JMO

SteveZ33

Hey Al, good to hear from you again. I understand the technique you describe above when putting it in auto mode to let the tranny rev match down shift when coming to a straight line stop or slow down. But how would you do it when slowing down for a turn or curve in the road? Stick it in auto mode as you enter the turn, then slap in back into manual in the middle or when coming out of the turn? I guess if this were the case you would have to stick in back in manual then tap it back a shift so you don't come out of the turn in 4th gear (or 3rd depending on your speed) ? Does this sound correct to you? How do you do it? I know, I know, too many questions

cloudy

iTrader: (3)

I have an 05 AT Z. So what exactly do you want to me test, ill be happy to test for ya

MikeNT256

Hey Cloudy!

Test out the whole throttle blip when you downshift. Tell me what exactly it does when you do the whole rev matching technology.

Aggro_Al

Hey Steve,

From what I've heard on other threads and forums, rev-matching the 5AT only gets you a smoother shift if you do it correctly. Unlike the 6MT, there isn't any performance advantage to rev-matching the 5AT. In the MY05 5AT, the computer does this for you in manual mode. In the pre-MY05 5AT, you had to blip the throttle at just the right time with the just the right amount of throttle or you would get a sloppy or slow shift. In the MY05 5AT you get a smooth shift at the expense of shift speed. It would be great if there was a way to override the auto downshift rev-matching for performance driving in manual mode.

IMO: In the pre-MY05 5AT, if you are going to use the manual mode, just shift, brake and accelerate as you would in a standard transmission and forget about rev-matching unless you can get the timining and feel right. The 5AT can jolt you a little bit if you are shifting aggressively but that is part of the price you pay for a fast shift. If you are going to use auto mode just stick in "D" and forget about it. In auto mode it will continually adapt regardless of the driving conditions. The reason I said it was easier to stick the pre-MY05 5AT into auto mode to rev-match is because I suck at it. It's not that easy. If you wanted to use automatic downshift rev-matching in a turn like you described just stick it in "D" before you enter the turn and back to manual mode after the turn. Otherwise, just leave it in manual mode and shift normally, rev-matching be damned.

The MY03-05 5AT in auto mode is driver and environment adaptable. It will learn your driving style and sense the environment and handling needs of the transmission. It does all this in real-time so it is continually sensing and adapting. In full auto mode if it needs to rev-match or engine brake, etc, it will do this automatically for you. In most cases, if you are driving aggressively into a turn the 5AT will adjust the transmission for entering the turn, hold the gear through the apex and adjust the the transmission for the exit. Of course, that all depends on your particular driving style, your current enviroment and your performance needs.

I personally have not driven the new 5AT and my opinion is just based on what others have said about it and what I've observed. If anyone has significant experience with both 5ATs it would be great to hear your opinion.

whitew

Can this capability be installed on pre 2005 350Z 5AT?

MikeNT256

Yeah thats actually a good question. I honestly wonder, if its just a software upgrade or programming upgrade to the ECU?