[travislambert]

Do you guys ever watch the wheel slip percentage on the eLSD display?

I have the manual transmission, which I've always felt like it's more difficult to take off than any of the manual transmission cars I've owned. Sometimes the engine just seems to have a mind of its own and suddenly cuts out as I release the clutch.

Just for fun I was watching the eLSD display, and I noticed the eLSD wheel slip % spikes and turns red at the same time the engine feels like it's cutting out. It seems likely there is a bug in their wheel slip % calculation that causes the ECM to suddenly pull power unnecessarily. To be clear, this happens even when I barely take off and there is ZERO slip. In fact, the more you slip the clutch to take off, the more wheel slip the eLSD display shows.

This also may be related to why the launch control sucks so bad on the manuals. People usually slip the clutch to take off hard and also avoid bogging or spinning. If the car thinks the wheels are spinning when they're not and pulls power, that would cause the car to behave similar to when the car pulls power due to torque management.

Does anyone know exactly how this wheel slip % is calculated? It certainly doesn't align with the traction control wheel slip indicator in any way.

[TJay74]

From what I read, I didn't think the eLSD was slipping but more how the computer is able to modulate the power to correct wheel when going around a corner which is the only real time when the eLSD comes into play I believe.

I've never seen more than 10% on the eLSD unless the rear tires were really spinning and the car was drifting sideways.

[FringBirdAloha]

This is true. Noticed it on my 6M. I haven’t messed with the custom launch parameters yet though.

[17CamaroZL1]

I'm running the auto, but I've also noticed mine show a little wheel slip on take off when it isn't spinning at all. I've never noticed any power being cut because of it though. The car has to spin pretty bad or slide sideways a foot or 2 before it cuts power. I thought it would monitor rear wheel speed to the fronts and/or left rear to right rear to determine wheel slip, but it makes you wonder.

[travislambert]

(I've updated the wording of the original post to more accurately describe my observations.)

I think this could be the root cause behind why these manual cars are so damn hard to drive. I had a '16 SS with a manual transmission (obviously without the eLSD) and it never bogged on take off like the ZL1 does.

It's also very difficult to get a good 60' at the drag strip with a manual transmission ZL1. Some of the problem is surely with torque management restrictions, but I believe the wheel slip miscalculation is adversely effecting launch as well. If you think about it, launch control certainly factors in a wheel slip % (configurable on the ZL1). If this calculation gets bogus readings while the clutch is engaging, it's almost certainly negatively impacting the launch.

[popsmk]

While I can certainly chalk it up to learning the new engagement point on this clutch, I too have noticed the eLSD indicator showing the same thing. My first thought was that it was configured to reset itself to zero at a stop (the red flash), but I have seen the slip spike up on a very gentle start. The bogging behavior comes on at random times with similar pedal and throttle engagement. I've noticed this in all driving modes - track seems to be the worst due to the aggressive change in throttle response.

I can corroborate that it "feels" like something is holding back at times.

[Shorty45]

I also felt that the problem with not being able to launch the M6, was somehow related to the eLSD. When I did mess with the custom launch % it just started acting weird on normal take offs and randomly reving up the engine (there's a thread about custom launch messing up) so I put it back. There is definitely something wrong with the M6 cars not being able to launch correctly. As was stated On the time sheets, the SS cars are launching better than ours, imo. All due to how the TC system supposed to work with eLSD. Interested in what you find out about it!

[Zach495]

I'm very curious if this is why my car feels slow to me. I had the car put on a dyno a couple weeks ago and it was reading 505 torque, where it should be around 560. It seems like something is pulling timing. I have a M6 with about 2200 miles on it and it never really felt like it's pulled hard to me. I was watching the eLSD system today and it's definitely acting funny. I can be at a light and just rev the car in neutral and it'll read 7%. Just driving down the road and giving it any gas will make the value increase %, without the wheels anywhere near breaking loose.

[travislambert]

Originally Posted by Shorty45

...the SS cars are launching better than ours, imo. ...

There is no doubt in my mind that there is a problem. I've owned both a 6th gen SS and 6th gen ZL1 now and there is a pretty big difference in the drive-ability.

I don't remember the SS ever bogging for seemingly no reason on a soft takeoff. The ZL1 does it all the time, and it's embarrassing. It makes me look like I can't drive a manual. I usually love a manual transmission, but there are days when I wish I would have ordered the A10.

To me the bogging while using launch control is secondary to the day-to-day driving, but I'm thinking the cause is the same. There is clearly an issue with the wheel slip % calculation on the ZL1. It makes no sense that it spikes like it does when the car is barely moving. I've done a little research and apparently, the Z06s that came out prior to the ZL1s had some serious eLSD software issues. My guess is that there are some leftover bugs.

The problem is I don't know who to contact. My local dealerships are a joke for the most part. They don't even know where the lift points are on the ZL1, much less how to diagnose a complex issue like this one.

Does anyone have Al. O's email or possibly another engineer that might actually look into the potential problem?

[travislambert]

Originally Posted by TJay74

From what I read, I didn't think the eLSD was slipping but more how the computer is able to modulate the power to correct wheel when going around a corner which is the only real time when the eLSD comes into play I believe.

I've never seen more than 10% on the eLSD unless the rear tires were really spinning and the car was drifting sideways.

That's interesting that you haven't seen the problem on the SS 1LE. It'd be next to impossible to miss, so maybe it's a ZL1 specific issue?

Come to think of it, there was a stock '17 SS 1LE kicking my butt on 60 foot times at the strip last week. I spent a good amount of time talking to him about how he was launching. He was just using straight up track mode without launch control. I tried the same, but the ZL1 was still falling on its face immediately no matter how much I slipped the clutch.

If you get a chance do me a favor and leave the eLSD display up for a few days (just to double-check). Try and vary how fast you release the clutch on takeoff and see if you notice an occasional wheel slip % spike.

[Shorty45]

I agree it's definitely feels like it's pulling timing. It would be interesting to find out what the Z06 had to do to fix it. I'm in the same boat with dealership issues, here. It's why I went to Texas to get my car. My friend Cal Webster, on here, and I have talked about how the car is pulling timing on launches. He has a few videos of him trying to launch. It's clear as day you can hear it. I am to the point now that I want to get a tune so that I can get what I paid for. I hope we all can figure this out.

[Zach495]

I tried to submit a report with chevy last night. They said take it to the dealer, to which I responded that I already did and all they did was look for codes, which they aren't going to find. They ended it with ok I will inform a senior advisor on this issue. I said it needs to be an engineer who knows this car. I will let you guys know if I hear anything and mention I'm not the only victim.

[travislambert]

Originally Posted by Zach495

I tried to submit a report with chevy last night. They said take it to the dealer, to which I responded that I already did and all they did was look for codes, which they aren't going to find. They ended it with ok I will inform a senior advisor on this issue. I said it needs to be an engineer who knows this car. I will let you guys know if I hear anything and mention I'm not the only victim.

That's awesome. If you'd like me to report the problem as well I will. Unfortunately though I doubt we get anywhere. All roads lead to dead ends with GM customer service. I get so tired of the "take it to the dealership" response. It's like saying "You know those guys who barely made it through high school? They're working at your dealership now so why don't you take your 65k car to them and let them tell you there are no codes being thrown".

Also, since it isn't a serious safety issue, the likelihood of GM fixing the problem for current owners is low.

I suspect our best odds are if someone who knows someone at GM sees the thread and decides to help. I'm very confident what we're experiencing is not by design.

Does anyone know if there will be any GM engineers at camaro fest we can speak with? That might be another route we could take. My overall satisfaction with this car would be so much better if it weren't for this issue.

[Repman]

Guys , I pick up my new ZL1 this friday , now I am questioning my decision to get a manual car instead of the auto. I am not a drag racer but will be taking it to the road course so dead stop launches are not what I will be doing with this car. Having said that is that the only time you experience the loss of power at drop clutch launches or is it pulling timing every time it senses some
wheelspin ? I would not be happy coming off a corner and having it cut power on me if the wheels spin a bit . Thanks for your input and sorry you are experiencing this issue.

Larry