[vtirocz]

Originally Posted by travislambert

I thought I'd post the summary I sent GM on June 25th in case anyone is interested.

Attachment 882224

Beyond the acknowledgement of the email, I haven't received anything. I'll keep you guys posted.

Good summary. Hopefully this gets passed to the appropriate engineering team that can investigate it further.

[bobby35ny]

Great Job!!
Thanks for doing that for us.
-Bobby

[FringBirdAloha]

Fabulous work.

[rasracin]

Been driving my M6 Vert since mid March and approaching 5000 miles. I understand the Vert does not have eLSD. I have experienced the losing power, almost stalling, and falling on its face phenomenon of the eLSD Coupe. I am a pretty accomplished stick guy including clutchless 4 speeds, Lencos and Jeffcos. This is by far the most difficult manual trans car to master and drive smoothly.

[travislambert]

Originally Posted by rasracin

Been driving my M6 Vert since mid March and approaching 5000 miles. I understand the Vert does not have eLSD. I have experienced the losing power, almost stalling, and falling on its face phenomenon of the eLSD Coupe. I am a pretty accomplished stick guy including clutchless 4 speeds, Lencos and Jeffcos. This is by far the most difficult manual trans car to master and drive smoothly.

I'm glad you chimed in. We need the Chevrolet engineers to hear from us manual transmission veterans that there really is a drivability issue with this car.

Also, I think you are 100% correct that this issue is not necessarily a function of the eLSD. When I created the thread I associated the issue with the erratic behavior of eLSD wheel slip % gauge, but I've found that behavior to simply be a nuance of the calculation. At this point I'm assuming the true issue is actually part of the Performance Traction Management software, but even that may not be 100% correct.

[travislambert]

Here's yet another thread about how this car is difficult to launch.

http://www.camaro6.com/forums/showthread.php?t=500323

There's a real issue here. I have my fingers crossed that the GM engineers can help us get it fixed.

[travislambert]

To this point I've been primarily focused on getting this bogging issue resolved for the purpose of daily driving. Today I sent an email to Ann (Camaro Brand Quality Manager) and Jim (Camaro Program Engineering Manager) containing feedback on my experience so far with the ZL1. In this email, I included a section about how there seems to be a problem launching the car at the dragstrip.

Here's the attachment I sent:

Camaro Suggestions (Redacted).pdf

Hopefully they'll be back in touch on the original wheel slip write-up soon. If you guys are having similar experiences to mine please tell your dealer, call GM, etc. so that this issue can be properly prioritized.

[Shorty45]

I'm taking my 1966 Chevelle SS to the parade tomorrow and had a few thoughts while I was driving it today. It's a 4-speed car, pretty much all stock in general. 1st gear is somewhat tall on my M-21; like 2.52:1 and with those mechanical stiff clutches, I have never had a problem with it almost stalling while taking off easy or hard like at the track. The ZL1 first gear has nothing to do with being too tall that it makes it harder to take off, imo. Its got a great clutch. But as Travis has said before there's something in the software somewhere, making it inconsistent among a few other things. To me, it seems like the response from the gas pedal to computer to motor is adding some uncertain or inconsistent variable. In my '66, I can leave from a stop the exact same way, in regards to clutch position and gas pedal: every time. With ZL1; i cant duplicate the same launch from a stop, in regards to clutch position and gas pedal. It's going to take a willing Camaro engineer riding with you so that you can show them what your talking about with the manual 6 speed, to understand what we r talking about because, it's kinda hard to put into words. But it either has to do with T/C, PTM, timing, eLSD or all the above and then some. Make no mistake, I love my car. Wouldn't trade it for anything. Would just like it to be able to launch correctly is all. Thanks Travis.

[OminouSS]

Originally Posted by 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.

What do you mean by 'so damn hard to drive?'

That is pretty strong wording. I have experienced no such hardship.

The thing with the eLSD is that every little effect is shown on the display as an intervention. It is not the case. Just run in track and you won't have any problems. The display pisses me off. If your tires are pressured incorrectly or you have odd sizes it seems to piss off the eLSD and the little squirly indicator lights up. I hear all the time that the car is overextended because 'I can see on your PDR that the car is losing traction'.

Bull$hit. Plain and simple. BS. There is very little intervention in Race/Track. Have fun.

[Stoner]

Hi guys. Here is another issue to throw into the mix. I am still under 1500 miles, so no hard launch yet. When I leave my ranch, I have to stop and wait for the automatic gates to open. There is a very slight incline leading up to the gates, so the hill assist kicks in. I can feel it hold the car for a couple seconds as I start to accelerate. But as soon as the car starts to move it falls flat on its face. I have to use 2-3 times the normal throttle to get things moving. It consistently does this, no idea why, but it's the only location I normally drive where the hill assist kicks in. When leaving the ranch I am normally in tour mode, as it's a bumpy ass road for 4 miles to the main road. I have not tried it in sport or track mode, but I will when we get home from vacation.

I have no idea if it's related to the hill assist, or if its just the incline. For background, I have been driving stick shifts all my life, including several years driving 18 wheelers. With the power the car should have, there is no reason for the lack of power to accelerate up a minor slope from a stop

Travis, great observation, and thanks for bringing this to light.

[FringBirdAloha]

Originally Posted by Stoner

Hi guys. Here is another issue to throw into the mix. I am still under 1500 miles, so no hard launch yet. When I leave my ranch, I have to stop and wait for the automatic gates to open. There is a very slight incline leading up to the gates, so the hill assist kicks in. I can feel it hold the car for a couple seconds as I start to accelerate. But as soon as the car starts to move it falls flat on its face. I have to use 2-3 times the normal throttle to get things moving. It consistently does this, no idea why, but it's the only location I normally drive where the hill assist kicks in. When leaving the ranch I am normally in tour mode, as it's a bumpy ass road for 4 miles to the main road. I have not tried it in sport or track mode, but I will when we get home from vacation.

I have no idea if it's related to the hill assist, or if its just the incline. For background, I have been driving stick shifts all my life, including several years driving 18 wheelers. With the power the car should have, there is no reason for the lack of power to accelerate up a minor slope from a stop

Travis, great observation, and thanks for bringing this to light.

I have this exact issue with the slight incline in my driveway. It hill assists, then if I give it normal throttle and clutch it seems the brakes from the hill assist are causing the eLSD to sense slip and then my engine power is cut and it bogs and I believe the only time I’ve stalled my zL1 was trying to get up the driveway. Unless I over throttle it to the point where I’m concerned about burning the clutch, then it won’t bog down.

[Infern0]

Originally Posted by Stoner

Hi guys. Here is another issue to throw into the mix. I am still under 1500 miles, so no hard launch yet. When I leave my ranch, I have to stop and wait for the automatic gates to open. There is a very slight incline leading up to the gates, so the hill assist kicks in. I can feel it hold the car for a couple seconds as I start to accelerate. But as soon as the car starts to move it falls flat on its face. I have to use 2-3 times the normal throttle to get things moving. It consistently does this, no idea why, but it's the only location I normally drive where the hill assist kicks in. When leaving the ranch I am normally in tour mode, as it's a bumpy ass road for 4 miles to the main road. I have not tried it in sport or track mode, but I will when we get home from vacation.

I have no idea if it's related to the hill assist, or if its just the incline. For background, I have been driving stick shifts all my life, including several years driving 18 wheelers. With the power the car should have, there is no reason for the lack of power to accelerate up a minor slope from a stop

Travis, great observation, and thanks for bringing this to light.

Good point and thanks for bringing this up. I've actually experienced the same thing 100% of the time the hill assist kicks in. You reminded me, I cringe when I see it pop up because I wonder if I'm going to stall it before I even take off.

[utsteve98]

Originally Posted by FringBirdAloha

I have this exact issue with the slight incline in my driveway. It hill assists, then if I give it normal throttle and clutch it seems the brakes from the hill assist are causing the eLSD to sense slip and then my engine power is cut and it bogs and I believe the only time I’ve stalled my zL1 was trying to get up the driveway. Unless I over throttle it to the point where I’m concerned about burning the clutch, then it won’t bog down.

Is this a true issue or is it the fact that the 1st gear ratio is 2.29? There are many cars out that that even their 2nd gear has a lower ratio. I'm sure if I took off from second in my current car I would have the same issue you all have on a hill.

[travislambert]

Originally Posted by OminouSS

What do you mean by 'so damn hard to drive?'

That is pretty strong wording. I have experienced no such hardship.

What I meant by that is that the car is somewhat unpredictable as it takes off from a stop. When power is pulled abruptly it can be difficult not to stall.

I'm glad it hasn't been a problem for you. I'm guessing you probably drive more aggressive than most if you haven't noticed the issue.

Originally Posted by OminouSS

The thing with the eLSD is that every little effect is shown on the display as an intervention. It is not the case. Just run in track and you won't have any problems. The display pisses me off. If your tires are pressured incorrectly or you have odd sizes it seems to piss off the eLSD and the little squirly indicator lights up. I hear all the time that the car is overextended because 'I can see on your PDR that the car is losing traction'.

Bull$hit. Plain and simple. BS. There is very little intervention in Race/Track. Have fun.

Since I started the thread, I've learned to use the eLSD display as more of a tool. I no longer believe it's the eLSD, but rather some aspect of PTM.