[travislambert]

Originally Posted by LSmith353

First, I should quantify my post here by saying I do not own a ZL1, nor have I driven one. But I read this section pretty much every day. The symptoms being described here seem similar to issues discussed in a previous thread about the rev limiter kicking in. http://www.camaro6.com/forums/showth...=493356&page=5 From what I can deduce from all of this, if your foot is even touching the clutch pedal in a ZL1, there is some form of logic at work to prevent damage to the drivetrain.

It's an interesting thought. Unfortunately not resting your foot on the clutch isn't really an option while taking off from a stop. I suppose you could rev it up and smash the shifter into first gear (just kidding).

I can't help but think it's related to the miscalculation of wheel slip %. I just need a chance to gather some more data. I'd like to get a video, but I only drive the car on nice days, and it's been raining on and off each day since I started the thread.

[Can'tHave2MuchHP]

He may be onto something, maybe once you get past a certain point you need to be off the clutch entirely in Chevy Camaro's teams' opinion. And the feature stops above 5,000 to prep for no lift shifts if wanted?

[travislambert]

Originally Posted by Can'tHave2MuchHP

He may be onto something, maybe once you get past a certain point you need to be off the clutch entirely in Chevy Camaro's teams' opinion. And the feature stops above 5,000 to prep for no lift shifts if wanted?

Maybe so, but it doesn't explain why it shows wheel slip when there isn't any.

[LSmith353]

Originally Posted by Infern0

I didn't read through the whole thing again, but if I recall correctly that feature doesn't activate until 5000 rpm.

If you read the tech bulletin that was posted (actually a picture of it), the ECM is monitoring what's going on with the clutch in relation to engine rpm, speed, clutch position and load at all RPMs. Like I said, I don't know anything, but maybe the ECM displays eLSD slip when it is actually clutch slip.

Yeah, i know its supposed to be from one side to the other, but the ECM knows how fast the back tires "should" be moving at any given RPM. Could be, when the back tires are moving slower than what the RPMs would indicate, the eLSD is "helping" limit torque by not applying full engagement to both back tires and not relying totally on cutting timing. Or it could be that it's just confused.....

[Infern0]

Originally Posted by LSmith353

If you read the tech bulletin that was posted (actually a picture of it), the ECM is monitoring what's going on with the clutch in relation to engine rpm, speed, clutch position and load at all RPMs. Like I said, I don't know anything, but maybe the ECM displays eLSD slip when it is actually clutch slip.

Yeah, i know its supposed to be from one side to the other, but the ECM knows how fast the back tires "should" be moving at any given RPM. Could be, when the back tires are moving slower than what the RPMs would indicate, the eLSD is "helping" limit torque by not applying full engagement to both back tires and not relying totally on cutting timing. Or it could be that it's just confused.....

Interesting theory. But recall my post above about slip registering even when I'm coasting in neutral (clutch fully depressed).

[Can'tHave2MuchHP]

Originally Posted by travislambert

Maybe so, but it doesn't explain why it shows wheel slip when there isn't any.

It may not be displaying wheel slip and is showing differential/drivetrain slip?

Idk maybe this has nothing to do with it.

[travislambert]

Originally Posted by Can'tHave2MuchHP

It may not be displaying wheel slip and is showing differential/drivetrain slip?

Idk maybe this has nothing to do with it.

I don't think it's differential slip. At its core the eLSD is just an open differential. There's no way for it to slip both wheels at the same time. So, unless one tire tire is moving faster than the other, the internal differential clutch isn't slipping. Since this problem happens while the car is going straight and neither tire is spinning, I've kinda ruled out the differential slip. (In my mind at least.)

The clutch slip is what I suspect is being factored into the wheel slip % calculation. With that said, I'm not sure why the powertrain would be factored into a wheel slip calculation at all. It seems reasonable that the wheel speeds and steering angle would be all they'd really need to calculate wheel slip. Trying to calculate wheel slip based on the engine RPM, clutch position, gear selection, etc. seems to be unnecessarily complicated, but I suspect something like this might be what GM is doing.

[travislambert]

I just remembered this thread from about a month back...

http://www.camaro6.com/forums/showthread.php?t=494147

I'd bet the first gear start problems described are caused by the same issue identified in this thread.

[bmlocal175]

When I watched this video of some 0 to 60 runs, the first thing I thought was how bogged down the car seemed on launch. Seemed like it was killing the times. Get past all his talking and just watch the runs.

[ELS1]

For the people who have tuned their car, are you experience similar issues?

[Boilermaker128]

The shift is hurting his times. Just let 1st gear rip to 100kph.

[BoostedX2]

Want to throw my .02 cents in...I'm an old guy, but all this traction control, torque management, etc just sucks...what we need is a car where you hit one button, called maximum acceleration, that puts all these variables in the right mode..don't really want to have to trial and error everything...is that not too easy for this day and age? just saying!!!! all this shit makes me crazy!!!!

[Blown355]

Originally Posted by Boilermaker128

The shift is hurting his times. Just let 1st gear rip to 100kph.

This.

[msawyer110]

You have to also realize how tall these gears are cause it makes so much power. My zl1 feels slower off the line than my 96 procharged z because the gears are so incredibly tall. Especially 1st. But i like it. Its harder to spin out of 1st and when i do race it 1st gear will actually be usable.