NO LIFT SHIFTING

[Normagene]

VegasZL1. Where you at an intersection (90 degree left or right) or in a curve and fully accelerated to allow the PTM 2 to modify the level of engine power for a smooth and consistent corner exit. (Owners Manual Pg 9-40). I've pulled out plenty of times making a left or right and punched it, the engine dies rights down even though I still have it floored, and I thought it was to stop all the wheel spin. Also tried exiting a really nice hi-way curve, punched it (WOT) but chickened out before the system modified the power. Didn't think I had the skill level and got to nervous before it started chirping in the turn. Speed I let off was 80 to 90. Too much to soon for a beginner. Didn't want to lose control of her so I backed off the acceleration.

[silverds]

Originally Posted by VegasZL1

Fair enough. I appreciate the honest answer. And FWIW, your response certainly seemed accurate...

I was driving the car just a few minutes ago, in PTM 2, and for the hell of it decided to just floor it after going around a corner (fairly low speeds) and keep the accellorator mashed (this was in 2nd gear). As the car built RPM's and the PTM was trying to reel in the massive amount of torque being sent to the rear wheels, the car was making exactly the same sounds as it does when you NLS...which leads me to believe what you wrote earlier.

I'm going to do some tests tonight and will report back with what hopefully will be some sort of conclusion to this.

I learned everything I know about the ZL1 from this article.

High Performance 2012 - Inside The 580HP Camaro ZL1

Not really but it is a really great technical article.

Here's the most pertinent info to this discussion. It talks about Launch Control specifically, rather than No Lift Shift however, we know they are related functions.

The Launch Control system functions through the Electronic Brake Control Module (EBCM) and the Engine Control Module (ECM), and is fed signals from the wheel bearing-based ABS sensors. The EBCM is where the wheel speed inputs go; it has the algorithm that requests whatever torque it thinks it needs. Most of the system's brains live in the EBCM, but the ECM holds the RPM and cuts spark/fuel/throttle. In short, the ECM does the torque mitigation and figures out how to deliver the torque, and the EBCM figures out how much torque it wants and makes the request. "A good driver can beat the Launch Control by usually 1 to 2 tenths," Tony admits. "But the Launch Control is consistent all day long. It factors in a cold outside temperature and knows that the engine is making a little more torque, or knows the engine is a little warm and is making less torque, and adjusts accordingly. This system's consistency prevents an inexperienced driver from going up in smoke because of a track or weather change."

[DrkPhx]

Here is what I've gathered about the no lift shift feature from experience and what I've read about on other GM models.

- The NLS algorithm is controlled in BCM
- Must be at or near WOT - 95% or greater TPS
- Shift must occur in .50 seconds or less (clutch engaged, shift gear and clutch disengaged)
- Must shift above a certain rpm 5000-5500 min rpm. I think it's 5000 rpms based on datalogging.
- The rpms will jump up during the shift (how much depends how close you shift to the rev limiter) and held at redline. The quicker the shift; the less chance it will jump up.
- The fuel/spark rev limiter (i.e. cut off) will not be activated at redline.
- If done properly; the supercharger will stay in full boost, PE (Power Enrichment -commanded WOT AFR) will be maintained as well as full WOT spark timing throughout the shift.

It would be nice to see the actual algorithm parameters; but once again this based on my own observations by driving and datalogging my own car and reading on other GM cars with this feature.

[joes407]

just gave this a try from a roll and it does work awesome! so it does work from a launch or roll. not that i didnt believe everyone, just had to see for myself.

[Normagene]

DrkPhx. Outstanding info! Good stuff to know. So from what I just read you can do this at anytime. I could be on the hi-way doing 50, downshift and punch it (WOT) and do the NLS. Or from a roll or from Launch Control. Sounds like this car is going to be a lot of fun.

[VegasZL1]

Okay People, here are some more videos.

After paying more attention to what the motor sounds like when it's hitting the rev limiter versus the sound it makes during the NLS procedure, I'd have to say that (as far as the sounds its making) what silverds says makes some sort of sense. I'm not sure what the point of limiting the available torque from the motor would be while the clutch is pushed in, unless it's to prevent the all of said torque from making you fly off the road once you release it... Again, it makes sense...but it's still an educated guess at best. However, at this point it seems to be the best explanation.


I tried to keep the camera as still as possible during this, but the jolts from the shifts make it a little difficult to watch the tach closely as you will all see...

The first video is simply running the car up to the rev limiter in second gear so you can hear what it sounds like:



The second, a launch in PTM3 with NLS. As you all probably know, PTM3 keeps active handling turned on, but for whatever reason the car was more lively than the later videos; which is why the video is somewhat crap in the beginning...I chose to keep the car on the road as opposed to going in the ditch:



Third video, PTM5 & NLS:



Fourth video is for those of you who were wondering about shifting at 5k. The way I sit in the car makes it difficult to see the tach, so I missed the 5k point for the first couple of shifts, but the 3-4 shift is right on the money. Done in PTM5:



Last video, same as above but done at 5500:

[mlee]

Originally Posted by ZL1-V

I was trying to coax Normagene to get used to shifting it close to redline using NLS. As you know since you have done it in your car it has to be done quickly as the needle still climbs. I don't drag race the car so it doesn't matter to me anyway, did that shit in my thirties!

Originally Posted by VegasZL1

When you NLS, the engine sits at the rev limiter while the clutch is pressed in. That's the sound you're hearing.

I'll try to make a video of this so you all can see, but it's hard to hold the camera in my left hand and get a view of the tach. I forsee task saturation in my future...

^^^ this is what I always thought

Originally Posted by joes407

lol, if you are asking is it possible to bounce off the limiter in that mode id say, of course if you shift at a snails pace or jam a gear. best thing to do is go somewhere where you have plenty of room and practice a couple times from a launch.

If you are shifting close as possible to the rev limiter (optimal) you will hit the rev limiter using NLS.

Originally Posted by joes407

i can say for sure that when using no lift shift you do not bounce off the rev limiter. i would also have to laugh and say the parachute/marshmallow description above will not be felt during no lift shift either :-)

See above... and I thought that was a great description of what it's like to hit the rev limiter during normal driving (not using NLS)

Originally Posted by VegasZL1

Okay People, here are some more videos.

Awesome job with the videos...


Great thread Normagene... Thanks for starting it.

[jbotta]

great vids

[joes407]

hmmm, i dont hear you chirping tires through those gears. i usually chirp third when performing this action.

[Genob4c]

I've been reading this great thread with interested. Dumb question time. A friend wants to know (not me of course), if NLS is active all the time, or do you have to be in a PTM mode? In the interest of full disclosure, I'm, I mean my friend, is driving a ragtop ZL1, and is limited to touring and sport mode. He uses the no lift shift method frequently, but not sure if he's getting the benefit of the NLS feature. He also sometimes turns off traction control, because he loves to see fear in the eyes of hapless Mustangs, and old ladies jump off the sidewalk when they hear the scream of his Conti Extreme Contacts. But I digress....

So is it always there?

Geno

[Normagene]

Geno. NO LIFT SHIFTING IS ACTIVE AT ALL TIMES. Launch Control is active when: In "Competitive Driving Mode" or for the ZL1's "In a PTM".

VegasZL1. OUTSTANDING VIDEOs! A pictures worth a thousand words. Great job. I've watched each one a half dozen times. Definitely going to give this a try - and real soon! During the Launch, it didn't seem/sound like there was ANY tire spin. I can hear the engine holding down the torque it seems. When I used Launch in my SS there was way to much tire spin. Seems like the ZL1 is dialed in way better for grip and fastest launch possible. Thank you so much for these videos!

[silverds]

Originally Posted by VegasZL1

Okay People, here are some more videos.

After paying more attention to what the motor sounds like when it's hitting the rev limiter versus the sound it makes during the NLS procedure, I'd have to say that (as far as the sounds its making) what silverds says makes some sort of sense. I'm not sure what the point of limiting the available torque from the motor would be while the clutch is pushed in, unless it's to prevent the all of said torque from making you fly off the road once you release it... Again, it makes sense...but it's still an educated guess at best. However, at this point it seems to be the best explanation.


I tried to keep the camera as still as possible during this, but the jolts from the shifts make it a little difficult to watch the tach closely as you will all see...

The first video is simply running the car up to the rev limiter in second gear so you can hear what it sounds like:

Thanks VegasZL1 for posting up these videos. You are a principle contributor to this thread and we all owe you a beer or something for being the documented Test Pilot.

[Genob4c]

Originally Posted by Normagene

Geno. NO LIFT SHIFTING IS ACTIVE AT ALL TIMES. Launch Control is active when: In "Competitive Driving Mode" or for the ZL1's "In a PTM".

Thanks!

Geno

[VegasZL1]

Originally Posted by silverds

Thanks VegasZL1 for posting up these videos. You are a principle contributor to this thread and we all owe you a beer or something for being the documented Test Pilot.

LOL!!! Thanks. I'll take some gas instead. I filled up on my way to the..uh...closed road course...to film these videos, and here was my gas gauge this morning (total of 32 miles)