Rev Limiter

Hi-Step'n370Z

This was inadvertently mentioned on another thread, but I wanted to bring this specific subject front and center, so I am posting it here.

Regarding the Rev Limiter:

As appreciated and explained by m4a1mustang;

Quote:
Originally Posted by m4a1mustang
If you are accelerating and forget to shift on time, yes, the limiter will kick in and keep you from over revving the engine. The limiter, however, will not save your butt if you accidentally shift from second to first instead of third.
Got it! Thanks.

On this thread, I want to specifically address this happening with the 7 speed auto:

It would seem that when you're cruising at highway speed, then slide over to manual mode, and your in 7th, or maybe 6th, the gear you're in would not change, but it DOES. It does not simply change to manual mode, and stay in the gear you were presently in before switching over to manual.

At normal highway speeds, it always goes to 5th gear the moment you slide over to manual. I do not know if you are already in 5th, and you switch over, what gear you're in, but I will gently try it and find out.

My point here is that if you "think" you're still in 7th, but you're really in 6th, or maybe even 5th, and you want to down shift into say 3rd, but you're not looking at the gear indicator window, and the tach at the same time, and pop the shifter 3 times, BOOM -you're all the way down to 2nd, and have revved well into the red line zone in a millisecond!

Talk about getting caught off guard! What a surprise that is.

Since this is something I do not want to replicate to find out, I instead have just been very careful and aware when I switch over to manual mode, and down shift.

When this happened, I have found is there is an instant decrease in power, and an intermittent surging of the engine. That is what I thought was the rev limiter doing it's job.

The scary part is that you're already into red line when that happens, but I don't think you're in far enough or long enough to do any damage to the engine, and the engine won't let you continue to accelerate thanks to the rev limiter.

Since this is something I do not want to replicate to find out, I instead have just been very careful and aware when I switch over to manual mode, and down shift.

To me, the answer was to "learn the Z" and practice by really watching the gear window, and note the speed you're traveling at the time of down shift.

Has anyone experienced this with the 7 speed auto?

What's the opinion regarding this down shifting scenario, and also the possible engine damage as the result?

Also, will the rev limiter save the engine because of the short time in red line?

JACKPAC

Your car will always downshift into 5th when you put it in manual. Nissan figures that if you are crusing in 7th, and shift over to manual, you're probably planning on passing someone. Why else would you shift over? So the engineers designed the tranny to be able to instantly shift to 5th so you can pass easily then you can either go back to auto, or shift up yourself. You don't have to look at the indicator window when shifting... just always know that you are starting in 5th! I actually like this feature. Very handy!

Hi-Step'n370Z

Good point, makes sense when you explain it like that.

cossie1600

I don't have the automatic, but does the car really have 7 gears or is 7th just locking the coverter up from 6th gear?

TBSS2008

If you're cruising on the highway and want the car to stay in 7th gear when switching to Manual mode just hit the + paddle once [While in (D)] you notice the car goes into M Mode and the 7 will display, then slap the stick over to full Manual Mode. The car will not downshift to 5th but stay in 7th gear.

Just curious how often do you guys with the Auto Z use Manual mode? I use Manual Mode 90% of the time. My only complaint about the Auto is when you’re not going fast lets say 40mph the car will up shift too many gears in my opinion and feels sluggish. It also tends to hunt for gears at low speed as well gets on my nerves so I find myself in manual mode almost all the time. Some times I wonder if I should have gone with the 6MT since I love shifting gears so much.

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m4a1mustang

The clutch would probably get old after a while, especially if you drive in any traffic.

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cfleming2226

I drive in manual the majority of the time, the car is far more responsive and ...well just more fun. AS an added bonuse it drives my girlfriend crazy

TBSS2008

That’s pretty funny my wife does the same thing, "why don’t you just put it in drive?"! I will usually put it in D for a few blocks to amuse her then right back to manual mode.

At lunch I thought I would play around with the D to manual mode switch and it works at any speed. Basically no matter how fast you’re driving once the car settles into gear you can up shift which puts the car into manual mode but does not change gears. It display the gear the car was already in while in (D) at this time you can slap the stick over putting the car into full manual mode the car will not auto downshift, pretty cool!

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cfleming2226

That is a good tip and a stealthy way to slip it into manual, she'll never know until I abruptly down shift and slid around a corner!

Hi-Step'n370Z

Good tip, gonna try it in a few minutes!!

Jordo!

Crusing, D; spirited drving, M.

M feels pretty pointless in parking lots, for example.

You can also use the paddles to downshift without sliding it over to M mode. It will autmatically revert back to D in a few seconds though.

You won't damage the engine dipping up to (or even beyond) redline for a second or two -- running the car for long periods of time past redline would presumably accelerate wear, however.

I'm guessing the rev limiter stops you from going into the red anyway.

To the MT guys: How effective is the rev limiter at preventing missshifts? Anyone done that yet?

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m4a1mustang

There's really nothing the limiter is going to do for you if you accidentally go from second to first instead of third under acceleration or if you down-shift from fifth to second when you were going too fast. The wheels are likely to lock up and you're going to over-rev and possibly lose control.

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Vegitto-kun

I am quite sure that you cant missshift with the AT?

if you are going to hit red it wont downshift

Jordo!

Correct. It will beep at you in annoyance as if to say "stupid human"

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