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-   -   7AT rev limiter (http://www.the370z.com/engine-drivetrain/51224-7at-rev-limiter.html)

UNKNOWN_370 03-13-2012 10:29 AM

Quote:

Originally Posted by Nick911sc (Post 1596356)
fixed :tup:

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 02:36 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 03:21 PM

Quote:

Originally Posted by Augustus (Post 1596972)
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 03:58 PM

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

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. :bowrofl:

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

Dark Sarcasm 03-13-2012 05:12 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 05:13 PM

Video nao

TerribleONE 03-13-2012 05:15 PM

subd...

m4a1mustang 03-13-2012 05:19 PM

Sub'd... lol

Sent from my Galaxy Nexus

Trips 03-13-2012 05:20 PM

:wtf2:

Dark Sarcasm 03-13-2012 06:25 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 06:26 PM

Quote:

Originally Posted by Dark Sarcasm (Post 1597552)
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 07:12 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 07:49 PM

Quote:

Originally Posted by Dark Sarcasm (Post 1597552)
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 07:53 PM

Quote:

Originally Posted by Dark Sarcasm (Post 1597552)
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:tup:

UNKNOWN_370 03-13-2012 10:09 PM

Quote:

Originally Posted by Dark Sarcasm (Post 1597552)
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 (Post 1593874)
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 :inoutroflpuke:
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.


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