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Phatman1 nervous about purchase of 2019 C7

Old 12-10-2018, 04:20 PM
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Phatman1
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Default Phatman1 nervous about purchase of 2019 C7

New to this forum: I have been impressed by the looks of the C7 Corvettes and I'm trying to convince my wife to let me buy one. I feel her breaking down.I have been doing online research on these cars and realistically I think I will just purchase a base model C7. I have no need to take it to the track so I most likely won't get the Grand Sport, although there are some features that would be pretty cool to have. I don't need a full fledged race car so I won't get the Z06.

I have digressed: I finally broke down and went to my local Chevy dealer to take a test drive. They brought the car from another lot 2 miles away and when I got into the vehicle the battery was dead. Once they figured out where the battery was located, a jump (after some trouble) got the car started. Okay so I'm ready to take my test drive. I had to back the car up and turn sharply because I was in the dealership parking lot and the front end started jumping and making sounds just like my truck does when in 4 wheel drive and you turn too sharply. Is this normal for the C7? It appears that this would create issues every time you had to maneuver in a parking lot. I have owned Chevrolet's in the past (Impala) for a company car and they have fallen apart at about 120k miles. Never have purchased a Chevy before so I'm nervous about spending that kind of money on a dream sports car only to have many failures. 2 questions: Does the C7 not like the sharp parking lot turns and I plan on keeping it as a daily driver will it last to 200k miles with regular maintenance?
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Old 12-10-2018, 04:25 PM
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Originally Posted by Phatman1 View Post
Does the C7 not like the sharp parking lot turns and I plan on keeping it as a daily driver will it last to 200k miles with regular maintenance?
No, the C7s tires do not like slow, sharp turns when it's cold out. Without Hoonin it, it should last well beyond 200k. I think there are some that are close.
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Old 12-10-2018, 04:28 PM
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What you felt is normal on a tight radius turn. Annoying but nothing to worry about.
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Old 12-10-2018, 04:41 PM
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I belive the tire chatter is normal for the c7 and there should be several threads you can read on it. It's a little odd at first but I got used to it. Also the c7 is an amazing car, I would highly recommend it.
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Old 12-10-2018, 04:53 PM
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The "Ackermann effect. It is "not" some design flaw. Here, watch this video to learn about this.


Basically, Corvette engineers decided that a tight turning radius is more important than eliminating the Ackermann Effect.

Because this effect only comes into play during slow-moving tight turns, like navigating a parking lot, Chevy left the system alone in order to provide superior performance and handling.

Last edited by MMD; 12-10-2018 at 04:55 PM.
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Old 12-10-2018, 04:57 PM
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Check out the forum vendors who will give you a better deal than your Chevy dealer. You can do a courtesy delivery to a local dealer if the forum dealer is not close to you. Search "courtesy delivery"

Good luck.
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Old 12-10-2018, 05:07 PM
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Skid Row Joe
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Originally Posted by Phatman1 View Post
New to this forum: I have been impressed by the looks of the C7 Corvettes and I'm trying to convince my wife to let me buy one. I feel her breaking down.I have been doing online research on these cars and realistically I think I will just purchase a base model C7. I have no need to take it to the track so I most likely won't get the Grand Sport, although there are some features that would be pretty cool to have. I don't need a full fledged race car so I won't get the Z06.

I have digressed: I finally broke down and went to my local Chevy dealer to take a test drive. They brought the car from another lot 2 miles away and when I got into the vehicle the battery was dead. Once they figured out where the battery was located, a jump (after some trouble) got the car started. Okay so I'm ready to take my test drive. I had to back the car up and turn sharply because I was in the dealership parking lot and the front end started jumping and making sounds just like my truck does when in 4 wheel drive and you turn too sharply. Is this normal for the C7? It appears that this would create issues every time you had to maneuver in a parking lot. I have owned Chevrolet's in the past (Impala) for a company car and they have fallen apart at about 120k miles. Never have purchased a Chevy before so I'm nervous about spending that kind of money on a dream sports car only to have many failures. 2 questions: Does the C7 not like the sharp parking lot turns and I plan on keeping it as a daily driver will it last to 200k miles with regular maintenance?
Most any new car or truck bought today will undoubtedly make it to "200K." I've put over 300K, on several cars, and 250K on another car. 100K, is nothing today. ALL my diesel coaches I've bought over 30+ years have easily made it to 100K, no sweat. If you're buying one, buy exactly what you want regards equipping it? Don't scrimp trying to save $5K +/- as many report doing - it's not worth it. Also; Order a new one! You won't regret doing so.

Last edited by Skid Row Joe; 12-10-2018 at 05:08 PM.
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Old 12-10-2018, 05:13 PM
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The tire hop at very low speeds is normal for this suspension that is designed for max sports car performance. Also, the OEM performance run flat tires have very stiff side walls and softer rubber compound which appears to contribute to the "hop".
I have heard that the all season tires ( I don't think they are run flat tires) pretty much does away with the low speed sharp turn "hopping" concerns.
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Old 12-10-2018, 05:23 PM
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Originally Posted by CubPilot View Post
The tire hop at very low speeds is normal for this suspension that is designed for max sports car performance. Also, the OEM performance run flat tires have very stiff side walls and softer rubber compound which appears to contribute to the "hop".
I have heard that the all season tires ( I don't think they are run flat tires) pretty much does away with the low speed sharp turn "hopping" concerns.
Not true ^^^^.

Front wheel hop is standard on the A/S Michelin tires.
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Old 12-10-2018, 05:25 PM
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Bought a new Chevy Tahoe a couple of days ago and the car wouldn't start. They put in a new battery and away I went. Wonderful SUV.
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Old 12-10-2018, 05:34 PM
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Originally Posted by CubPilot View Post
The tire hop at very low speeds is normal for this suspension that is designed for max sports car performance. Also, the OEM performance run flat tires have very stiff side walls and softer rubber compound which appears to contribute to the "hop".
I have heard that the all season tires ( I don't think they are run flat tires) pretty much does away with the low speed sharp turn "hopping" concerns.
I would suspect that if in fact there is any difference in tire behavior between the OEM tire and any other tire it would be due to the differences in rubber compounds used in the respective tires. The Ackermann effect is real. Corvette engineers have decided to not take this effect into account as it will provide better "higher speed" tire performance (i.e., having big azz tires up front). The inner tire will actually "hop" on a slow speed tight turn as the tire is actually "twisting" on the pavement and this hop movement is what everyone is hearing. Regardless of the different tire you use, this hop will occur. The rubber compond may attenuate the sound but not the actual hop.
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Old 12-10-2018, 05:58 PM
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Originally Posted by MMD View Post
The "Ackermann effect. It is "not" some design flaw. Here, watch this video to learn about this.

https://youtu.be/oYMMdjbmQXc

Basically, Corvette engineers decided that a tight turning radius is more important than eliminating the Ackermann Effect.

Because this effect only comes into play during slow-moving tight turns, like navigating a parking lot, Chevy left the system alone in order to provide superior performance and handling.

Actually this guy does a better job explaining it, because British accent.


I mean, I love Jason from Engineering Explained. He does a pretty good job of making complex mechanical problems easy to understand for the layman. But his video primarily pertains to how the Ackerman steering affect a 4WD system where power and drive is delivered to all 4 wheels, including the steering wheel (front).

Kyle's video explains WHY for performance and high speed applications you want the anti-Ackerman effect, or minimize the Ackerman steering effect. But if you set up your steering rack and geometry that way, in slow speed, tight corners where a wheels slip angle does not come into effect for the purpose of turning and lateral grip, that same anti-Ackerman effect that's so crucial to high speed cornering all of a sudden become a detriment because now the outside wheel is turned further in and causes the front outside wheel to "push."

And this effect is felt more as the front tire is wider and the sidewalls become shorter, because the tires are not as compliant and won't flex as much to absorb the chattering effect on a steering that is set up to be "anti-Ackerman" for performance reasons. The way Kyle explains it, the only way to eliminate that effect (i.e. tire chatter for slow, tight turns on a car setup for anti-ackerman at speed) is to have a variable steering geometry, similar to what some high-end luxury cars have where planetary gears inside the rack can vary steering ratio from side to side. Those systems are rare and far and few in between (although as that technology gets worked on more, you see more and more luxury cars come with active steering type systems) right now.

The BEST way to explain it, at least in a way *I* would understand, is this. Cars that are designed for high speed performance applications, will have anti-Ackerman steering effect. Cars that are designed to go around towns and make lots of right angle turns, will have pro-Ackerman effect. MOST street cars you see today will design the steering rack and ratio to point the inside tire further in, or pro-Ackerman, to assist in slow, tight turns with small radius. High performance sports cars will have anti-Ackerman, or the outside wheel turned in further, to assist with high slip angle as required for maximum grip on performance tires.

If you look at the video you might think, "well isn't that just toe-in and toe-out?" No. This is how steering linkages are set up, that under turning and tire load, the inside front tire will angle MORE on most steering rack setup. So while a car with a front toe-out will turn-in and respond faster, same car with the toe-out will turn better in a tight, slow radius turn if the steering rack is designed to use the Ackerman effect to turn the inside tire further OUT, while a car with toe-out with anti-Ackerman will return the car to a zero toe state or even slight toe-in after initial turn-in.

Which is to say, simply, that Corvette engineers choose to optimize for high speed, high performance tire slip angles rather than low speed, low slip angle turns. The side effect is that while the Corvette will set lap records and be skid-pad king, because it optimizes the outside tire grip in sacrifice to additional chassis torque to rotate the car, it suffers tire chatter in slow turns because the outside tire's turning radius is smaller than the inside tire on turns (anti-Ackerman). If we all have a chance to drive open wheel formula cars on the street and in parking lots, I'm sure we'd all be complaining about the same thing (most open wheel formula race cars are setup with anti-Ackerman steering).
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Old 12-10-2018, 06:08 PM
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Originally Posted by The HACK View Post
Which is to say, simply, that Corvette engineers choose to optimize for high speed, high performance tire slip angles rather than low speed, low slip angle turns. The side effect is that while the Corvette will set lap records and be skid-pad king, because it optimizes the outside tire grip in sacrifice to additional chassis torque to rotate the car, it suffers tire chatter in slow turns because the outside tire's turning radius is smaller than the inside tire on turns (anti-Ackerman). If we all have a chance to drive open wheel formula cars on the street and in parking lots, I'm sure we'd all be complaining about the same thing (most open wheel formula race cars are setup with anti-Ackerman steering).
Nice... Well done!

Lot's of GREAT deals out there bud (example --> https://www.warechev.com/VehicleDeta...24131653#close )

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Old 12-10-2018, 06:16 PM
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Originally Posted by Skid Row Joe View Post
Not true ^^^^.

Front wheel hop is standard on the A/S Michelin tires.
My A/S Michelin’s totally eliminated the “ wheel hop “.
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Old 12-10-2018, 06:33 PM
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Originally Posted by Skid Row Joe View Post
Not true ^^^^.

Front wheel hop is standard on the A/S Michelin tires.
That is not my experience with the Michelin A/S 3+ ZPs. I have experienced zero wheel hop since putting these on, including very tight parking lot turns in sub-40 weather.

Joe, do you have Michelin A/S tires on your C7???
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Old 12-10-2018, 06:45 PM
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Buy the car you won't regret it. Just take it slow when purchasing it and make sure you get everything you want on it. If your on the fence about an option just get it because you'll be sorry in the long run if you don't. Don't worry about the tire chatter completely normal. I thing if you got different tires it may eliminate this Good luck with your purchase and do your research Your going to love this car
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Old 12-10-2018, 07:25 PM
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Originally Posted by Phatman1 View Post
I finally broke down and went to my local Chevy dealer to take a test drive. They brought the car from another lot 2 miles away and when I got into the vehicle the battery was dead. Once they figured out where the battery was located, a jump (after some trouble) got the car started.
If your're going to use the C7 as a daily driver, you won't have problems with a dead battery. If the car is going to sit for a few weeks at a time without being used, order the $100 Battery Protection Package option. You will get a battery tender/charger ready to use by just plugging it in the outlet in the rear compartment. You'll want to get this if you do store the car in the winter.

You'll be glad you bought a C7 if you do. Good luck.
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Old 12-10-2018, 07:40 PM
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Originally Posted by The HACK View Post
Actually this guy does a better job explaining it, because British accent.

https://www.youtube.com/watch?v=O2ONv5MrpFg

I mean, I love Jason from Engineering Explained. He does a pretty good job of making complex mechanical problems easy to understand for the layman. But his video primarily pertains to how the Ackerman steering....
A little wordy. Your explanation and the video would serve well in a technical or engineering school but in a culture that now falls asleep reading anything more than 144 characters at a time it strains most laymen's faculties to comprehend these principles. If you were a Corvette salesman and you were giving a propective client/customer/layman a test drive in which they commented, "OMG...what the hell is that noise" would your reply be the same as what you had posted? Don't get me wrong. I appreciated your post. Good info presented and thanks for taking the time to post it.
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Old 12-10-2018, 08:57 PM
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Originally Posted by Skid Row Joe View Post
Not true ^^^^.

Front wheel hop is standard on the A/S Michelin tires.


The PS3+ A/S did it on my Z51 and does it on my GS. It ain't that big a deal....
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Old 12-10-2018, 09:07 PM
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Apart from everything else, go ELSEWHERE! The fact the dealership didn't even know where the battery is says it ALL. Get one somewhere else and ENJOY !!!
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