[travislambert]

Originally Posted by Infern0

As I suspected, I may have started to compensate for these issues. Though that may not be a complete act futility at the moment. I may have found something that works with relatively repeatable success.

My typical method of driving a manual car typically involves a "blip" in the accelerator with a gradual reduction in accelerator depression in an amount equal to the rate of clutch release up until the point of full engagement. Then at that point gradually reapplying the desired amount of accelerator. Right or wrong for daily driving that's been my style.

What I've been having more success than failure with in the ZL1 over the last couple of days is starting with the accelerator blip, but then holding it at the desired position, roughly 1K RPM give or take (still working on the right number), then beginning the clutch release throughout, maintaining the constant position of the accelerator.

I've only done this a few times over the last day or so, so I'm still trying to determine the rate of success with this method, or whether it's completely random. Also still trying to nail down the right RPM for this method.

Thoughts? Anyone else able to give this a shot?

What you describe is basically what I've done to train myself to be able to drive this car. At least this way when it pulls power, there is enough time to recover without stalling.

[travislambert]

Originally Posted by DFW1LE

I think GM engineering/QC should hand Travis a job offer. Well done!

I've been writing software for about 20 years. During that time my brain has basically rewired itself to detect issues quickly. Some people really appreciate that about me, and others... well, not so much.

Although I doubt GM ever gives me the opportunity to review their pre-production vehicles, I'd be glad to do it.

Thanks!

[BSR-1]

Originally Posted by Infern0

As I suspected, I may have started to compensate for these issues. Though that may not be a complete act futility at the moment. I may have found something that works with relatively repeatable success.

My typical method of driving a manual car typically involves a "blip" in the accelerator with a gradual reduction in accelerator depression in an amount equal to the rate of clutch release up until the point of full engagement. Then at that point gradually reapplying the desired amount of accelerator. Right or wrong for daily driving that's been my style.

What I've been having more success than failure with in the ZL1 over the last couple of days is starting with the accelerator blip, but then holding it at the desired position, roughly 1K RPM give or take (still working on the right number), then beginning the clutch release throughout, maintaining the constant position of the accelerator.

I've only done this a few times over the last day or so, so I'm still trying to determine the rate of success with this method, or whether it's completely random. Also still trying to nail down the right RPM for this method.

Thoughts? Anyone else able to give this a shot?

I'm pretty close to this, without the blip. I just end up giving it more throttle than should be needed and slipping the clutch enough so that when it does cut power I still have enough revs/clutch slip to keep it going.
I'd rather not abuse the clutch so much but it seems the only way to deal with this without getting rear ended when it stalls.

[Zach495]

So I sent in a claim through general motors. They said to bring it in and they will check it out. 1 week later, they report everything is working as it should. It's basically reading a value of how much input the hydraulic clutch needs to work to counter act some other forces. I'm not sure I buy it. Especially when I can get it to read 19% wheel slip just from revving the engine in neutral. I'm going back to my steering problems for now (car counter steers during hard turns when on a road course), then i'll revisit this problem.

[GarnetRedJuan]

Here's a link to it happening on my A10. Too bad you can't see the wheel slip on the PDR recording but you can hear it pretty clearly I believe. I was in Track mode with Race PTM on. It was hot out and the tires were already warmed up:

https://youtu.be/SSBox3UK7Mo

Here is a link to what the car can truly do. This was just a spur of the moment pull and the tires broke free:

https://youtu.be/MlF1HbhxZqA

[Infern0]

I was under the impression this was going to be brought up for discussion with some key folks from GM at the Camaro fest this last week. Anyone have anything to report?

[ELS1]

Don't want to divert this thread, but do other vehicles (GM or not) have similar issues? The back of my mind tells me this is actually a feature (taking into account the clutch protection doc) in order for GM to cover the car under track usage. But nonetheless, I'm glad that GM is acknowledging this.

The software on these cars are getting complex, there's bound to be undocumented features (bugs), but I can't imagine they didn't notice this issue when testing out the car in the real-world. Perhaps they used a different version of the software on these test cars? Probably published the code from a different branch (seems silly, but I've seen this done many times)? Who knows, I'm just coming up with silly scenarios at this point. Can't wait to see what they come up with.

[travislambert]

Originally Posted by Infern0

I was under the impression this was going to be brought up for discussion with some key folks from GM at the Camaro fest this last week. Anyone have anything to report?

What you are looking for starts at post #207.

In summary we seem to be moving closer to having a fix... GM needs some data, but it's going to be a few weeks before a device for my car will be available.

[Infern0]

Originally Posted by travislambert

What you are looking for starts at post #207.

In summary we seem to be moving closer to having a fix... GM needs some data, but it's going to be a few weeks before a device for my car will be available.

Thanks. The "view first unread post" button failed me. Took me right past that.

Fantastic news. Thanks again.

[PinHead]

MODS:

Can we please make this a STICKY?

[PinHead]

Originally Posted by ELS1

Don't want to divert this thread, but do other vehicles (GM or not) have similar issues? The back of my mind tells me this is actually a feature (taking into account the clutch protection doc) in order for GM to cover the car under track usage. But nonetheless, I'm glad that GM is acknowledging this.

The software on these cars are getting complex, there's bound to be undocumented features (bugs), but I can't imagine they didn't notice this issue when testing out the car in the real-world. Perhaps they used a different version of the software on these test cars? Probably published the code from a different branch (seems silly, but I've seen this done many times)? Who knows, I'm just coming up with silly scenarios at this point. Can't wait to see what they come up with.

Tell GM to make a flash copy of the Tune from the Nurburgring ZL1 and compare it to your version. That will give you an interesting base line

[stkshft]

Among all of the manual cars I have owned, the ZL1 has been the most challenging to get going from a stop, however, it is not difficult after some practice. I have stalled the car once but attribute that to being my own mistake by not giving it enough throttle to make it up an incline. First gear is also really tall and I feel like I have to feather the clutch a little bit more compared to previous cars. All that being said, I love the way this car drives!

[travislambert]

I appreciate the ideas, but there's a software problem on '17s. There's no question about it. A little birdie told me the '18s coming off of the line have new driveability fixes (the '17s do not).

Let's be patient. I have faith the GM engineers are going to take care of the '17 owners. I will get the Control Tec installed on my car as soon as it's made available. We'll get the data and be on our way to getting a software update.

[FringBirdAloha]

Originally Posted by Lt1z350

Not sure if anyone has tried to make sure all 4 tires are at exactly the same pressure especially the rears. I know sounds trivial but if they have the tolerance too small then a shorter tire caused by low air pressure could piss this system off. Worth a try and then recheck the data your seeing. I build transmissions for a living and will tell you on this new stuff we are seeing a lot of stupid stuff like this even make cars shift weird or neutral out. Things we see in the real world they didn't find in testing.
I have been following things like this as I am getting ready to buy one and if wasn't already set on the auto this would have pushed me to it. Just the fact the auto on a roll will whip a manual car was enough for me from the start. Funny how 5 years ago Manual would destroy an auto but now other way around. The way they build these new automatics they are near bullet proof and loss through them with all the new light weight parts is minimal.

Anyway if I had a manual I would be trying this tire pressure thing first then if didn't help jumping the front wheel signals to the rears and seeing if that made a difference. Has to be beyond aggravating when trying to drive the car normal and have this happen.

The A10 has been giving more than a few forum members here trouble like slipping, hard downshifts, and high temps. It will never be as track durable as the Tremec. This is why it’s not in the ZL1 1LE and GM knows it.