7AT rev limiter

UNKNOWN_370 · 03-13-2012, 11:29 AM

Quote:

Originally Posted by Nick911sc

fixed

haha j/k, I was thinking the same thing. Pretty useful if true.

My car bogged down and started revving hard at 4800rpm and the needle was bouncing between 4700rpm and 5000. It felt like if I tried to push the gas any harder I was going to break something in the engine. My wife was with me and she bore witness. Its an awesome feature and even though I'm guilty of it too...
I'm shocked no one just said, hey let me try this in the year and 1/3 there has been anv 11/12 models. The 09 and 10 models didn't even have the selection in the computer. We had that option now and nobody even touched it in all this time? They just figured its for the light and handed out false preaching???? Wow.

Augustus · 03-13-2012, 03:36 PM

Very interesting.

Set the light for 2k and try the experiment again. @5K, there's going to be some natural strain/resistance from the engine. The instant you back off the throttle, the AT's going to upshift. But @2K, there's no resistance; the engine will very freely rev above 2K and it should be very easy to tell that it's actually limiting revs. Put it in Manual mode, floor it. If it actually holds you at ~2K without shifting, then it's a bona fide rev limiter. Neat.

In my 6MT, the setting triggers the light. Nothing more, nothing less. It does not actually limit the RPM range. I can set my light for 2K and wind it out to 7k+ RPM. Makes zero difference to the operation of the engine. The owner's manual makes no indication that it should actually affect engine performance, either for an AT (5-15) or MT (5-19).

And other than the 4k RPM limit suggestion during break-in, why would this shift-limit feature actually be useful? Can't you just use your right foot to control the shift point? The AT will do what every AT does and automatically react to the throttle input. What purpose does it serve to be able to set an arbitrarily low limit? I mean, it's like a self-imposed limp-mode. I get it that it's an interesting feature, just curious why you'd ever really use it.

You crazy AT drivers.

UNKNOWN_370 · 03-13-2012, 04:21 PM

Quote:

Originally Posted by Augustus

Very interesting.

Set the light for 2k and try the experiment again. @5K, there's going to be some natural strain/resistance from the engine. The instant you back off the throttle, the AT's going to upshift. But @2K, there's no resistance; the engine will very freely rev above 2K and it should be very easy to tell that it's actually limiting revs. Put it in Manual mode, floor it. If it actually holds you at ~2K without shifting, then it's a bona fide rev limiter. Neat.

In my 6MT, the setting triggers the light. Nothing more, nothing less. It does not actually limit the RPM range. I can set my light for 2K and wind it out to 7k+ RPM. Makes zero difference to the operation of the engine. The owner's manual makes no indication that it should actually affect engine performance, either for an AT (5-15) or MT (5-19).

And other than the 4k RPM limit suggestion during break-in, why would this shift-limit feature actually be useful? Can't you just use your right foot to control the shift point? The AT will do what every AT does and automatically react to the throttle input. What purpose does it serve to be able to set an arbitrarily low limit? I mean, it's like a self-imposed limp-mode. I get it that it's an interesting feature, just curious why you'd ever really use it.

You crazy AT drivers.

There's no resistance at 4800rpm when flooring it to 7500rpm EVER. The resistance came for the FIRST time ever when I set rev limiter...

Why would we use the Rev limiter? Wow, I can't believe you just asked that. But hey...

1) to aid in what would be optimum shifting for torque we would want to be somewhere around 200-400rpms past max torque. Max torque would be 5200rpm so the ideal setting around 5500rpm.
2) to utilize max horsepower without overreving as well. 7200rpm is prime because 7000rpm is peak HP. We shift in manual mode. And we can do 95% of what a real manual does except burnouts.
3) making sure we make ideal shifts for fuel econ. 4400 rpm would ensure we are not driving sporty. Some of us have a led foot which means we can't control ourselves. Rev limiting would help be a reminder.

PS I can check to see if it works at 2000rpm but it worked as it should at 4800. Don't be jealous if your manuals can't. Lol

Augustus · 03-13-2012, 04:58 PM

As a means to control your AT to do perfect peak HP/torque shifts, then I get it. Fair points.

But how do you reconcile the difference between peak HP and torque? I mean, what do you choose? Torque for DD, HP for the track? Reminds me a little bit of the Top Gear M3 test where 0-60 took 5 minutes because of the required iDrive settings.

As an electronic nanny to keep you from speeding ....

Dark Sarcasm · 03-13-2012, 06:12 PM

i'm not sure if we are talking about the same thing anymore??!!! on my 2011 i can only set the REV LIGHT in the controls of the dash. and it only allows for adjustment of the REV light from about 6500 up to redline. I'm gonna go walk the dog and then test this out. I want video if this is true.

Red__Zed · 03-13-2012, 06:13 PM

Video nao

TerribleONE · 03-13-2012, 06:15 PM

subd...

m4a1mustang · 03-13-2012, 06:19 PM

Sub'd... lol

Sent from my Galaxy Nexus

Trips · 03-13-2012, 06:20 PM

Dark Sarcasm · 03-13-2012, 07:25 PM

Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z.

Red__Zed · 03-13-2012, 07:26 PM

Quote:

Originally Posted by Dark Sarcasm

Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z.

Ohjhhhh snapppp

UNKNOWN_370 · 03-13-2012, 08:12 PM

Ok so I set the limiter to 2500 and went out on the highway instead of the street. Figuring maybe the blocks I was on may posiibly not have been long enough and following up like I was asked to. I went out and floored it on the highway. What I did notice was at first as the light was blinking. Resistance was present and it felt like the car was bogging down. As i I stayed persistant this time on the throttle. It broke past the RPM setting and stayed with a solid light.
I did notice where ever I set the limit I did get resistance and I could feel where I needed the shift and didn't need the light. But it did rip past through once the blinking stopped and the solid light appeared. I tried this in various settings and the resistance would occur wherever I set the rev limit.
Ex: if the limit was set to 2500rpm, that's where id feel bogging at every gear. But if I set it at 4k that's where the new sensation of bogging down was. But once the light goes solid, bogging breaks and the car drives normal.
My guess its a way to protect the car in case you forget where you set the limiter. Things should be explored like if this can be activated fully with a tune? The rev-range goes to 9000 rpm on the limiter. Anyway... this is the conclusion. Sorry for not taking it out on the highway and checking it on the slam for over 1000 ft. The bogging was hard enough on the street that I would change gears before the light went solid.
But this thread allows us to know more about it which is good.

m4a1mustang · 03-13-2012, 08:49 PM

Quote:

Originally Posted by Dark Sarcasm

Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z.

That's what I figured.

Did you feel any resistance?

Jamaica · 03-13-2012, 08:53 PM

Quote:

Originally Posted by Dark Sarcasm

Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z.

Thats all we needed to hear. Thanks for the useful info

UNKNOWN_370 · 03-13-2012, 11:09 PM

Quote:

Originally Posted by Dark Sarcasm

Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z.

Quote:

Originally Posted by Dark Sarcasm

the setting in the instrument cluster doesnt change when the trans will shift. It only changes when the little red "REV" light starts blinking. You can set it between 6500 and redline.

So which one is it? 6500 to redline? Or 2000 to 8000? Mine is 2k to 9k. Looks like our cars might be different... lol

Anyyyywaaayyyyyy....
I just realized today that I drove completely in manual. I'm going to check if auto mode has any differences in performance. Yesterday I did auto and manual.

Just so u know guys I'm not here tryin to fk up shyyt n fight. I'm just tryin to figure out where this thing works. I hadn't used it and now I'm just trying to figure it out with you all. I did feel resistance according to where I set it except 2k and 3k didn't feel as hard as the higher gears. 4-6 felt aggressive in the pull back. I did this thoroughly today except I didn't do it in auto. I will do it tomorrow.

03-13-2012, 03:36 PM	#17 (permalink)
Augustus Base Member Join Date: Jan 2012 Location: Illinois Posts: 146 Drives: 2011 370Z Touring M6 Rep Power: 14	Very interesting. Set the light for 2k and try the experiment again. @5K, there's going to be some natural strain/resistance from the engine. The instant you back off the throttle, the AT's going to upshift. But @2K, there's no resistance; the engine will very freely rev above 2K and it should be very easy to tell that it's actually limiting revs. Put it in Manual mode, floor it. If it actually holds you at ~2K without shifting, then it's a bona fide rev limiter. Neat. In my 6MT, the setting triggers the light. Nothing more, nothing less. It does not actually limit the RPM range. I can set my light for 2K and wind it out to 7k+ RPM. Makes zero difference to the operation of the engine. The owner's manual makes no indication that it should actually affect engine performance, either for an AT (5-15) or MT (5-19). And other than the 4k RPM limit suggestion during break-in, why would this shift-limit feature actually be useful? Can't you just use your right foot to control the shift point? The AT will do what every AT does and automatically react to the throttle input. What purpose does it serve to be able to set an arbitrarily low limit? I mean, it's like a self-imposed limp-mode. I get it that it's an interesting feature, just curious why you'd ever really use it. You crazy AT drivers. Last edited by Augustus; 03-13-2012 at 03:59 PM.

03-13-2012, 06:12 PM	#20 (permalink)
Dark Sarcasm Track Member Join Date: Dec 2010 Location: Katy Texas Posts: 552 Drives: 11 CTS-V Coupe Rep Power: 16	i'm not sure if we are talking about the same thing anymore??!!! on my 2011 i can only set the REV LIGHT in the controls of the dash. and it only allows for adjustment of the REV light from about 6500 up to redline. I'm gonna go walk the dog and then test this out. I want video if this is true. __________________ wax Last edited by Dark Sarcasm; 03-13-2012 at 06:12 PM. Reason: not sure why i mentioned the dog walking

03-13-2012, 06:15 PM	#22 (permalink)
TerribleONE A True Z Fanatic Join Date: Jan 2009 Location: Socal Posts: 10,203 Drives: WOT Rep Power: 5850	subd... __________________ 638WHP 541WTQ @ 13.5PSI Build thread

03-13-2012, 06:19 PM	#23 (permalink)
m4a1mustang A True Z Fanatic Join Date: Feb 2009 Location: Northern VA Posts: 55,385 Drives: on two wheels Rep Power: 6962	Sub'd... lol Sent from my Galaxy Nexus __________________ - Steve Zs & Coffee - Saturdays at 10AM in Fairfax, VA and Columbia, MD (Click the banner!) LIKE us on Facebook!

03-13-2012, 06:20 PM	#24 (permalink)
Trips Administrator Join Date: May 2009 Location: Disneyland, Ca Posts: 8,732 Drives: 🔰 Rep Power: 10	__________________

03-13-2012, 04:58 PM	#19 (permalink)
Augustus Base Member Join Date: Jan 2012 Location: Illinois Posts: 146 Drives: 2011 370Z Touring M6 Rep Power: 14	As a means to control your AT to do perfect peak HP/torque shifts, then I get it. Fair points. But how do you reconcile the difference between peak HP and torque? I mean, what do you choose? Torque for DD, HP for the track? Reminds me a little bit of the Top Gear M3 test where 0-60 took 5 minutes because of the required iDrive settings. As an electronic nanny to keep you from speeding ....

03-13-2012, 06:13 PM	#21 (permalink)
Red__Zed A True Z Fanatic Join Date: Jul 2010 Location: window seat Posts: 28,940 Drives: Mostly on two wheels Rep Power: 120	Video nao

03-13-2012, 07:25 PM	#25 (permalink)
Dark Sarcasm Track Member Join Date: Dec 2010 Location: Katy Texas Posts: 552 Drives: 11 CTS-V Coupe Rep Power: 16	Myth - BUSTED. What is being referred to as a rev limiter is labeled "up shift" in the controls on the dash. I was able to adjust it from 2000 rpms up to like 8000 rpms. I have always had mine set at 6500 and always make it to redline. For this thread I moved the "up shift" to 4100. The only difference was the REV light came on at 4100. In manual and automatic it went to redline and back, with that little red light on solid after about 4300 rpms. Unless your model is differnt than my Z, there is no manually operated rev limiter in the Z. __________________ wax

03-13-2012, 08:12 PM	#27 (permalink)
UNKNOWN_370 A True Z Fanatic Join Date: Jul 2009 Location: ny'r livn in tx Posts: 8,687 Drives: well over 130m.p.h. Rep Power: 14858	Ok so I set the limiter to 2500 and went out on the highway instead of the street. Figuring maybe the blocks I was on may posiibly not have been long enough and following up like I was asked to. I went out and floored it on the highway. What I did notice was at first as the light was blinking. Resistance was present and it felt like the car was bogging down. As i I stayed persistant this time on the throttle. It broke past the RPM setting and stayed with a solid light. I did notice where ever I set the limit I did get resistance and I could feel where I needed the shift and didn't need the light. But it did rip past through once the blinking stopped and the solid light appeared. I tried this in various settings and the resistance would occur wherever I set the rev limit. Ex: if the limit was set to 2500rpm, that's where id feel bogging at every gear. But if I set it at 4k that's where the new sensation of bogging down was. But once the light goes solid, bogging breaks and the car drives normal. My guess its a way to protect the car in case you forget where you set the limiter. Things should be explored like if this can be activated fully with a tune? The rev-range goes to 9000 rpm on the limiter. Anyway... this is the conclusion. Sorry for not taking it out on the highway and checking it on the slam for over 1000 ft. The bogging was hard enough on the street that I would change gears before the light went solid. But this thread allows us to know more about it which is good.

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