[mlee]

Originally Posted by Gunkk

Haven’t taken her up to Bradenton motorsports yet, but she’s done a 3.7s 0-60 with a hard launch and no bog, but a bit of tire spin.

Has never bogged on the street. Not once.

Hmmmm now you really have me wondering. Can you repeat that 3.7?

[travislambert]

Originally Posted by Gunkk

Yep that’s the hypothesis... Travis’ data is pretty convincing.

That is interesting. I'm sure the convertibles run a slightly different software baseline, so there could be something there, but I believe there have been some guys with the convertible ZL1 who have experienced the "bogging" problem. I don't recall the transmissions for these cases though.

I'm a bit of a skeptic by nature, so I can't help but think that under more controlled circumstances, such as a drag strip, your experience would be similar to the rest of us. I've actually noticed myself that high-traction surfaces are slightly more problematic for "bogging", which makes sense if it's because it's reaching torque limits in the software.

Anyway, just to be clear, I don't have any data that ties to the eLSD specifically. I thought the eLSD was related originally, but I really can't think of a reason why the eLSD would matter unless it's just something coincidental.

The nuances with the wheel slip % and the conservative torque management are my two primary suspects. One area I haven't looked into much is the Performance Traction Management (PTM). There could be a tie in there, but I simply don't have a way to capture the data to be sure. I suspect PTM needs to know exactly how much grip is available in order to work. To know how much grip there is, GM must be letting the wheels slip a little on purpose (and then pulling power to regain grip). I don't know how much PTM is integrated into the launching of the car, but it seems plausible that there could be a relationship there.

The good news is, the poll is looking promising for this question. I've been making educated guesses for about 8 months now with no way to validate the theories. I'm really looking forward to knowing what's actually happening.

[ninetres]

I can’t count how many videos I’ve seen of stock a10s leaving hard(ish) with zero bog. I’ve never noticed bog in my a10 although admittedly never really focused on max effort launches from a dig.

And I don’t think I’ve EVER seen a video of a stock m6 leave hard, without bog. Hard for me to think both platforms suffer from the same issue. We know they both have TM.....but not anywhere near the same amount IMO.

[Boost Creep]

In an automatic, the driveline is loaded whenever the car is in gear then accelerated. Pressure is already applied to the entire driveline, and then increased quickly.
In a manual the entire driveline is slack until the clutch is released. You go from zero load, to work, all at once. All the lash in the diff is taken up, all the lash in the trans is taken up, the driveshaft is loaded and power is applied.

The abrupt application of power in the manual versus the smoother "softer" application in the automatic may be why the same potential issue seems different and worse with the manual ZL1. A combination of torque management and traction control/Elsd programming.


I've never experienced this in these cars, just my thoughts from what I've seen posted.

[CruzySS]

IMO the M6 Bog and A8 shudder should both be asked with all the activity they are getting. One gets asked this month and the loser gets asked next month. Then everyone is happy.

[vtirocz]

Originally Posted by CruzySS

IMO the M6 Bog and A8 shudder should both be asked with all the activity they are getting. One gets asked this month and the loser gets asked next month. Then everyone is happy.

I agree.

[Infern0]

I'm kinda nervous about the answer already.

[mlee]

Originally Posted by ninetres

I can’t count how many videos I’ve seen of stock a10s leaving hard(ish) with zero bog. I’ve never noticed bog in my a10 although admittedly never really focused on max effort launches from a dig.

And I don’t think I’ve EVER seen a video of a stock m6 leave hard, without bog. Hard for me to think both platforms suffer from the same issue. We know they both have TM.....but not anywhere near the same amount IMO.

Yes, we may be talking about two different things since leaving "hardish" M6 bog seems to be there and not on the A10. I'm talking about full on launch and not sure how you could see this on a video. Try some 0-60 runs when you get a chance. I'm betting a 3.7 is the best you will get and it won't be repeatable. 3.4 is advertised

Also, TM and Bog... are we using these terms interchangeably?

[CruzySS]

Originally Posted by Infern0

I'm kinda nervous about the answer already.

I bet everyone is. The answer probably is that's how it was made. If gm was going to address a fix it would of been done by now. Seems to be a design flaw not an issue since all the M6 transmissions do it.

[ninetres]

Originally Posted by mlee

Yes, we may be talking about two different things since leaving "hardish" M6 bog seems to be there and not on the A10. I'm talking about full on launch and not sure how you could see this on a video. Try some 0-60 runs when you get a chance. I'm betting a 3.7 is the best you will get and it won't be repeatable. 3.4 is advertised

Also, TM and Bog... are we using these terms interchangeably?

I don’t think the term is interchangeable but I think it’s the TM that’s causing it. I’ve seen tons of videos of a10s leaving hard, 60’ 1.7 or so. I’ve never seen an m6 do that. Most videos they fall flat on their face before the leave.

[mlee]

Originally Posted by ninetres

I don’t think the term is interchangeable but I think it’s the TM that’s causing it. I’ve seen tons of videos of a10s leaving hard, 60’ 1.7 or so. I’ve never seen an m6 do that. Most videos they fall flat on their face before the leave.

That's true and I've been side by side with them. A lot is the driver as well, but overall the M6 is virtually impossible.

[Gunkk]

Originally Posted by mlee

Hmmmm now you really have me wondering. Can you repeat that 3.7?

Odds are yes. It was my first try.

[PinHead]

Originally Posted by mlee

That's true and I've been side by side with them. A lot is the driver as well, but overall the M6 is virtually impossible.

Here's a thought;

Does anyone thing the Factory Loaded Tune Parameters are the same in both the A10 and M6?

You can get away with a "Soft Launch" with an Auto but not with the steep gearing of the M6.

Just a Sunday with Beer and the Internet........

Btw, I haven't been able to log into a ZL1 to do a Data Dump.

[bmlocal175]

A8 caught up in one day on votes? That's not good.