[HyperBlueX2]

No issues with mine..... been up there pretty high...... only time I get anything close to that is early mornings, cold tires and roads........ but its just under really hard acceleration.... early into my drive....

[VAZL1]

Have you checked your rear rims for hairline cracks? Just a thought

[catdog]

Originally Posted by OldJedi

Mike, this was also a problem with Z06 Vettes. It was like driving a Jeckyl and Hyde car. If I eased into the throttle it was quick and stable. If I stomped on it, it was a totally different animal with a mind of it's own. It was a very fine line between the two. The rear always broke loose and fish tailed no matter what the mode. They helped/fought to keep it somewhat controlled but I knew I could not drive it without all the nannies on. It was like a hair trigger if I gave it too much, I had a very healthy respect for its power. Having spent a lot time driving my ZL1, the LT4 is a much different engine than my LSA. A lot bigger difference than just 70HP. I know you are a much more capable driver than I and I'm very interested to hear what the engineers at the Fest have to say about the issue. See you next week.

I agree with you, have driven mine in wet which accentuates the cars behavior and lowers limits. Bottom line even in snow/ice mode if you get on it, the stabilitrak can't keep up with power and you can get in trouble quick. Happened also in tour on humid road when I got on throttle a little aggressively tail stepped out at 40mph the corrected. So on dry likely same would happen at higher speeds and limits. Bottom line the car is a monster and no amount of nannies can get around that. In some cases the traction control system steps in and limits torque but it seems in other situations it doesn't. Not sure if it's programmed to back off intervention if you get on throttle aggressively but the last week has me being a little more respectful of car than prior, maybe it's getting more broken in at 1500 mi but it's turning into a proper beast in all sense of the word.

Also some members in warmer states with perfect road surfaces may not experience above as much.

[FringBirdAloha]

Been up to 140 and solid as a rock. Planted in the ground like concrete. Only time I’ve ever felt uneasy is in rain, especially where water has puddled. The car gets squirly in the rain due to the tires.

[KLR ZL1]

Originally Posted by mlee

I didn't put a wrench on it but did a good shake down and couldn't feel anything loose. Might be a parking lot check in order when we get to BG. I'm trailering the car anyway.

That's one of the reasons I figured the drag radials would help with traction. And when I was on the drag strip with Goodyears at 120 mph I know it wasn't breaking loose there but definitely hard to hold on to. But your right the normal driving doesn't seem to be an issue. I'm also used to losing a lot of traction on the launch and peddling through that but on the top end it's crazy.

I think I would be fine in the turns. Seems driving straight is the biggest issue.

Not trying to make more out of this than it is but damn my confidence is definitely shaken and could easily see this thing going bad. If Pete can't figure it out I'll take it to the dealer and I'm guessing that will be an ordeal in it self. How do you tell a tech to do a WOT 0-60 and hang on to your car.

Mike, if you checked parts unloaded, it is harder to detect. Like the front swaybar issue. Also there has been an issue with incorrect torqued rear suspension parts as well as the front sway. Like others have said have alignment checked and re torque all bolts.

[7WSM]

I have experienced this several times at the track. But it's not very consistent and would be hard to repeat. I am thinking it has something to with the surface of the road maybe? I have been on other roads (Westpark Toll) in Mexico making a lot higher speed runs and never felt the rear end getting loose.

[Stephen12ZL1]

check the rear cradle bolts and anything that attaches the rear to the car itself. Check sway bars (especially the end links that have been loose on many cars). Get the car on a rack and see if anything else could be loose and not properly torqued. Mine feels stable, solid, and I have no squirrely feelings up to 100mph. I'm still in break-in mileage at 705 miles on the clock. The car sounds like it has that feeling like a rear tire is flat or under inflated which we know isn't the case.

[hjdca]

Note: Any low speed wobble is always a tire issue, maybe a separated belt or something.

[cwebster]

I've never had stability issues with my M6 on stock tires at any speed up to nearly 150 MPH. It's always been rock solid.

I did feel a bit squirely with the new DRs on the big end at the drag strip but I attributed that to the wider sidewalls, low tire pressure, and cross-winds that day.

I put the car up on a lift and do a safety inspection before each track visit. So far no loose components. Still, as others have suggested, there is a bulletin out about loosening struts (ZL1 Front Struts FYI). This may not be detectable by hand on a lift.

I don't see how old differential fluid would cause the behavior you describe but I do change mine after every 1 or 2 drag strip trips, depending on how hard it's driven. Faulty eLSD could potentially cause instability if it clamped down with too much pressure or at the wrong time. travislambert has opened this thread to investigate eLSD issues with the M6: eLSD Wheel Slip % on M6

I hope this gets resolved soon. I'd be interested to know what's causing it too. I can imagine how frustrating it is.

--Cal

[mlee]

Originally Posted by PinHead

If this is the case, we really need to push to have a "by-pass mode" for Track use, (where these safety software nannies are deactivated).

I'd rather be in full control of the car, instead of always having the threat of a unexpected "Drive-By-Wire" Event.

on Drag Radials I always go all off. Tried it both ways

Originally Posted by HyperBlueX2

No issues with mine..... been up there pretty high...... only time I get anything close to that is early mornings, cold tires and roads........ but its just under really hard acceleration.... early into my drive....

yeah, I think I just have an issue to track down.

Originally Posted by VAZL1

Have you checked your rear rims for hairline cracks? Just a thought

Two different sets of wheels tried...

Originally Posted by catdog

Also some members in warmer states with perfect road surfaces may not experience above as much.

I'm one of those people..

Originally Posted by 7WSM

I have experienced this several times at the track. But it's not very consistent and would be hard to repeat. I am thinking it has something to with the surface of the road maybe? I have been on other roads (Westpark Toll) in Mexico making a lot higher speed runs and never felt the rear end getting loose.

Originally Posted by Stephen12ZL1

check the rear cradle bolts and anything that attaches the rear to the car itself. Check sway bars (especially the end links that have been loose on many cars). Get the car on a rack and see if anything else could be loose and not properly torqued. Mine feels stable, solid, and I have no squirrely feelings up to 100mph. I'm still in break-in mileage at 705 miles on the clock. The car sounds like it has that feeling like a rear tire is flat or under inflated which we know isn't the case.

Exactly my plan of action. Just putting a huge damper on my Fest activites, but those are normally limited anyway. I'm trailering the car there anyway.

Originally Posted by hjdca

Note: Any low speed wobble is always a tire issue, maybe a separated belt or something.

Two different sets of tires.

[mlee]

Originally Posted by cwebster

I've never had stability issues with my M6 on stock tires at any speed up to nearly 150 MPH. It's always been rock solid.

I did feel a bit squirely with the new DRs on the big end at the drag strip but I attributed that to the wider sidewalls, low tire pressure, and cross-winds that day.

I put the car up on a lift and do a safety inspection before each track visit. So far no loose components. Still, as others have suggested, there is a bulletin out about loosening struts (ZL1 Front Struts FYI). This may not be detectable by hand on a lift.

I don't see how old differential fluid would cause the behavior you describe but I do change mine after every 1 or 2 drag strip trips, depending on how hard it's driven. Faulty eLSD could potentially cause instability if it clamped down with too much pressure or at the wrong time. travislambert has opened this thread to investigate eLSD issues with the M6: eLSD Wheel Slip % on M6

I hope this gets resolved soon. I'd be interested to know what's causing it too. I can imagine how frustrating it is.

--Cal

Yes, I would have thought the same about big sidewall DR's too. And this may very well be related to eLSD that Travis describes. We hope to address this at the fest (or at least ask the proper questions).

[90503]

If you are trailering it, take it to the fest and slam the crap out of it!...lol....(just don't crash).....Like HAL in Space Odyssey suggested...let if fail, then you'll know what it is that's wrong.....

I wouldn't let it turn the fest into a bummer for you....Get some engineers in it with you, and let it rip....

[BMWM.D.]

+1 on getting that car on an alignment machine. Wouldn't be surprised if you had a rear toe issue. New cars can definitely be far from ideal. It's pretty common from what I've experienced working on brand new cars over the years. Cheap and easy to check.

[datboi448]

I have felt the fish tailing in three scenarios, heavy accel from low speed, heavy braking on a turn, and very heavy rain at any speed over 30 mph which is more tires