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Discussion Starter #1 (Edited)
NLS (No Lift Shift)? Can someone confirm or deny?

Howdy:

I'm sure this has been touched on by someone...but my search didn't uncover it.

Can anyone confirm or deny the No Lift Shift capability of the manual C7?

I've found little info on this topic but edmunds claims it to exist...

Thanks,

-John
 

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News to me.
 

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There was a thread on this on another forum and although a couple people insisted it worked when used in conjunction launch control, no one can present any documentation from GM to confirm it.


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We called this "speed shifting". Every stick car could do it if the driver was willing to try. I've done it in my C7 with no ill effects in track mode/launch control and without.
 

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We called this "speed shifting". Every stick car could do it if the driver was willing to try. I've done it in my C7 with no ill effects in track mode/launch control and without.
As I I recall, speed shifting was not using the clutch, I could be wrong. The system described here requires the use of the clutch, you just keep the throttle mashed to the firewall and when you clutch between gears the computer prevents over revving.


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Maybe the jargon varies by location? I always referred to no lift shifting as power shifting. It's tough on a car...especially if miss a shift! The only place I did it regularly was the drag strip.
 

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As I I recall, speed shifting was not using the clutch, I could be wrong. The system described here requires the use of the clutch, you just keep the throttle mashed to the firewall and when you clutch between gears the computer prevents over revving.
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I can confirm that the feature you describe here works with the cruise control.... When on the highway, cruise set at any speed, you can depress clutch and shift without touching the throttle, cruise remains set and engine does not over-rev. I loved this during my break-in period as it allowed me to cruise the highway home for 700 miles, changing engine RPM by switching between 4, 5, 6 and 7th gears (WITH REV MATCH ON).
 
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Has anyone else been using this feature and have more information about it? As said, it can't be found in any documentation...unless I'm missing something.
 

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I gave this a spin (literally) the other week. 2014 Z51 FE4 NPP 7MT. With launch control and ARM engaged I flat footed the skinny petal whilst grabbing second. The engine bounced off of the rev limiter and the transmission closed the second gear gate, forcing me into neutral. Basically the car said F**k You. As far as I'm concerned we do not have NLS.
 

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I gave this a spin (literally) the other week. 2014 Z51 FE4 NPP 7MT. With launch control and ARM engaged I flat footed the skinny petal whilst grabbing second. The engine bounced off of the rev limiter and the transmission closed the second gear gate, forcing me into neutral. Basically the car said F**k You. As far as I'm concerned we do not have NLS.
Did you use the clutch or attempt a speed shift?
 

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I have z51 2014 m7 I power shift the car all the time great trans 2nd to 3rd a little tricky but no problem remember you have to use the clutch I have powershifted cars all my life this one shifts nice.
 

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The no lift shift, is that you can shift with out letting off the gas peddle , it holds the rpm so you wont hit the rev limiter between shifts, that's it. You must us the clutch peddle to shift from one gear to the next. if you don't use the clutch peddle, and try to power shift you will blow the synchronizers out of the tranny. $$$$$$$$$ Speed shifting is (using the clutch peddle), and power shifting is (not using the clutch peddle).
 

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What I don't know is if NLS is active whenever you are at WOT or if letting up at all during a pass disables it. If it's pass sensitive then it's entirely a drag racing thing. If it's enabled whenever you are are WOT then it could be used on a road course too. I also believe it requires you to be in track mode (or a PTM mode for MRSC owners). All of these would be great things to have answered by a Corvette Team engineer instead of people guessing on the Internet............
 
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Here's some VCM Suite data taken from a C7 M7 (obtained from some other C7 enthusiasts):

NLS.jpg

I interpret this to indicate that the NLS algorithm becomes active when throttle position exceeds 75% and the Vehicle Speed Sensor (VSS) measures speed greater than 31 MPH.
 

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I recall you posting that in the past but I still would like to see it explained directly to understand when that section of code is executed. I don't doubt the fact it's there, I would just like to have it confirmed the values in those table are even accessed and if they are, under what conditions. I've seen my share of code that reuses libraries containing tables that are never accessed. If you take the time to put it in the code why not take the time to describe it's function in the manual.

With all the communication that seems to occur between the Corvette team and various members of the forums and media I'm surprised this hasn't been discussed.
 
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If you take the time to put it in the code why not take the time to describe it's function in the manual.
Because the engineers are super cool, but the people in the documentation departments are too comfortable with cutting and pasting from previous years without going to great lengths to add new sections?
 

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More anecdotal evidence:

"We did the first "base" run in the Touring configuration with stability control and traction control fully on (see numbers in parentheses), and without utilizing the no-lift shift feature. With all aids turned off and the car in Track mode, our best run came using a 2,500-rpm launch, allowing us to go to full-throttle pretty much immediately. It hooks up well. The no-lift shift feature allows you to just jam the shifts home, and this excellent gearbox is fully accepting of it. We tried a couple of launch control runs, but because it launches at about 4,300 rpm it gets too much initial wheelspin, making it slightly slower."

2014 Chevrolet Corvette Stingray Track Tested on Edmunds.com

Hmm, I now see this is the same link as the OP's. So good, it's worth repeating.:)
 
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I tried this in my c7 z51 with MSRC and could not get it to work....just hit the rev limiter :/. What has to be done to enable the nls?
 
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