Phatman1 nervous about purchase of 2019 C7
#1
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?
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?
#2
Burning Brakes
#4
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.
#5
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.
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 03:55 PM.
#6
Le Mans Master
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.
Good luck.
#7
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?
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?
Last edited by Skid Row Joe; 12-10-2018 at 04:08 PM.
#8
Advanced
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 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.
#9
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 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.
Front wheel hop is standard on the A/S Michelin tires.
#11
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 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.
#12
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.
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).
#13
Scientific Negotiator
Member Since: Jul 2005
Location: USA
Posts: 6,397
Received 1,835 Likes
on
1,018 Posts
St. Jude Donor '07-'08-'10, '14
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).
Lot's of GREAT deals out there bud (example --> https://www.warechev.com/VehicleDeta...24131653#close )
#14
Race Director
#15
Moderator
Joe, do you have Michelin A/S tires on your C7???
#16
Melting Slicks
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
#17
Pro
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.
You'll be glad you bought a C7 if you do. Good luck.
#18
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....
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....
#19
Team Owner
Member Since: Aug 2007
Location: I live my life by 2 rules. 1) Never share everything you know. 2)
Posts: 136,148
Received 2,400 Likes
on
1,365 Posts
St. Jude Donor '11-'12-'13, '16-'17-'18
#20
Race Director
Member Since: Mar 2001
Location: Bonneville Salt Flats, 223mph Aug. '04
Posts: 17,381
Received 5,188 Likes
on
3,440 Posts
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 !!!