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Discussion Starter · #1 ·
I have 2015 Corvette Stingray 2LT Convertible 8 Speed Automatic

It has been a wonderful car...I drive it very gently and I have 15,800 miles and average gas milage is 23 miles per gallon

Over the last 4 weeks I am noticing the following

When I accelerate heavily ..i.e. try to get 0 -60 in 4 to 4.2 sec...the car starts doing zig-zag and it feels like it is getting out of control

In the past the car would accelerate perfectly and straight

What do you think may be the reason for this

Appreciate your help or any suggestions you may have

Thanks
 

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Tires worn?
 
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tripchowdhry, welcome aboard, your tires are good, traction control working? Could it be the road condition?

SF
Rick
 
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check cold tire pressures with accurate hand gauge.
 
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The problem is in the rear of the car, since you are not adding steering input (given that this is straight line acceleration).

You don't have the ediff, since your car isn't a Z51.

This leaves the TC system (and the remote possibility of the Stabilitrak system). I would disable the TC system and repeat your straight-line acceleration test.
 

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Just a little bit of uneven tire wear would be enough to cause this issue however in this case it is probably just rear tires that are worn AND the remaining rubber is now harder from the many heating/cooling cycles they have been through.

I am not sure where the OP is located but it could be buildup on the road if it has been rain free for many days. My doctoral program was in Lubbock TX and the first thing I noticed out there on my initial visit was even little old ladies were squealing their tires going around corners but it was because of the dust buildup on the roads interacting with the pavement and the tires and not all of them thinking they were the little old lady from Pasadena.
 

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Discussion Starter · #13 ·
Thanks Everyone:

I also noticed one more thing...I have performance exhaust ...I have it set on Auto...and car is set in Sport...

Previously, the car noise would be loud and I used to enjoy it...now days the car noise is not that loud

Also, I feel the acceleration/power has reduced somewhat ...for example if I am going at 60 mph, and I floor the accelerator ...it seems it is slow to reach 85 mph than before...

Any help on what may be happening

Appreciate it
 

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Could be your brake system issue in conjunction with AH/TC
As stated disable those systems and try again.

If what you're saying is accurate about the sound, it almost sounds as if the car is stuck in eco mode or whatever.
Did you try the 0-60 timer with the conditions you describe? "feeling" isn't the most accurate form of measurement.

The highest acceleration isn't just blasting on the gas and hoping for the best. It's modulating the throttle in at the edge of traction with the rpm of the motor. You should also evaluate how heavy you're on the gas.

In many performance RWD cars if you just stomp on the gas the car will spin from a stand still and should be considered normal.

Not saying you're doing it wrong, especially with your observation of the exhaust note and perceived drop in performance, just brining things up for consideration.

Also, what is the tire temp when you do this?

Cold tires especially pilot super sports are like driving on ice...not sure what you have though as you don't seem to have a Z51.

Also, alignment... get that checked out too.
 

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Discussion Starter · #16 ·
Thanks for all your feedback

Just to make sure I understood perfectly

1) "Could be your brake system issue in conjunction with AH/TC As stated disable those systems and try again"

I start the car, and press the selector in the center to disable the traction Control
I use the selector, select the "Sport" again, even if on Dash it says "Sport Selected"

How do I get tire temperature - I only see pressure on the Tire

I will show my tires to Costco and see what they say

I will go to the dealership, and request wheel alignment

Probably I should have this done by tuesday or wednesday and update you all

Thanks a ton
 

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Thanks for all your feedback

Just to make sure I understood perfectly

1) "Could be your brake system issue in conjunction with AH/TC As stated disable those systems and try again"

I start the car, and press the selector in the center to disable the traction Control
I use the selector, select the "Sport" again, even if on Dash it says "Sport Selected"

Hmm, since as you say you usually drive very "gently" and you're calling the lack of traction, "Zig Zagging" I would suggest NOT shut off the "nannies" unless you are in a very large parking lot with lots of room on both sides and are prepared to understand what it is like to have the car jerk so rapidly to the right or left that you have no time or knowledge on how to react!

I have a '34 Ford ProStreet Rod with an 8.2 liter engine (set back 6 inches,) 53% of the weight on the rear wheels, 4 bar link adjustable rear suspension, a very rigid chassis but only Positraction.

Positraction is all you'll have with a non Z51 and the nannies shut off. If one of my tires gets traction and the other doesn't because of the road crown , etc, there is less than a second to lift or I'd be in a ditch! I have been driving fast cars fast for 50 years and I would not shut off the "nannies" in my C7!


How do I get tire temperature - I only see pressure on the Tire

As someone posted, you can't! That warm/hot indicator seldom reads hot in my C7 unless in the hot summer after some spirited driving! If the outside temp is below 65 F would not think of testing the 0 to 60 times in my street rod that has 16.5 inch section width sticky Mickey Thompson tires. To achieve the ~3.3 second times as measured on my GTech Pro the tires must be hot. Can feel that with my hand.

I will show my tires to Costco and see what they say

Frankly relying on someone from Costco to tell you IF the tires are OK or warn if they are are warn unevenly just reinforces the thought of "don't turn off your nannies." There are some good video's on the net that show folks with C7's going off the road or into a tree trying fast acceleration with them turned off! That requires more skill than it sounds like you have-sorry.

I will go to the dealership, and request wheel alignment

Although alignment could be a small contributor, tire temp and condition (how evenly they are warn) are probably more of a factor, IMO.

Probably I should have this done by tuesday or wednesday and update you all

Thanks a ton
You may have more driving skill than your questions or answers indicate so sorry if I have underestimated! However rather be sorry for that than not telling you of the possible consequences of turning off the "nannies."
 

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It's difficult for me to enjoy the C7 with TC on - TC limits the car so much - but experimenting in a remote or vacant parking lot makes a lot of sense, depending on the level of experience the OP has.

I performed about a dozen hard accelerations in 1st and 2nd over the last two days, with TC off to see if I could reproduce the zig-zag effect the OP descibed.

In each case, I kept the throttle at the maximum level I could before inducing any significant wheel spin.

The only time I was able to induce a zig-zag motion was when I did encounter wheel spin, and my steering inputs where slightly out of phase with the rear end slide - so I would say that I actually induced the zig-zag response with my light steering inputs.

More food for thought.
 

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Tires! I noticed exactly this with mine at the same mileage. Add to this breaking loose when hitting corners in the city because I have the Z06. I found the rubber to be much harder with the tire so worn and, once replaced, all was fine again.
 
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