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Come on ladies and gentlemen, how different can a C8 electrical system be than a C7 system? Not like the C8 will be landing on Mars. Appears to me to be delays to absorb C7 inventories on the ground.
Electrical power requirements have been dropping over the years. Modern digital circuits require lower voltages and consume less amps. So, even though modern cars have more electronic components, they have not added much to the electrical load. Minor exceptions might be servo motors to change shock settings (orifice based), change ride height, etc. As mentioned previously, the big gotcha would be the impact of the wiring to support hybrid operation.
Since the hybrid version of the Corvette is years away, I would hope that they would use a separate or an additional wiring harness for it. My guess would be that that the control signals for hybrid operation would be integrated into the current buss structure; whereas, the heavier gauge wiring for the battery / motor connections would be separate.
Last edited by PurpleLion; 12-13-2018 at 11:14 AM.
Load is a basic engineering exercise. Not like the engineers as guessing at the requirements.
Hard to believe they could undershoot it so far as to cause any delay......
Just my .02 cents.... I can understand that load should be a basic engineering function. Shouldn't cooling needs be similar? We are in year 5 of the Z06 and from what I understand there continue to be issues tracking a "track car" with the optional automatic when it is hot outside. Or the cost equation of putting wheels on it that won't frequently crack and bend. Much like how hard can it be to find a glue that keeps the leather from peeling off the dash that has been happening since the C6. My faith in GM to do the right thing is much lower now than it was when I bought my first new GM car in '84. I believe GM has some of the best engineers around and can easily fix the above issues if they chose to, but it comes down to a cost equation of how much it will cost them during the warranty period vs cost to keep the problem from happening in the first place.
I hope they begin to look a little closer at customer experience and risk to their brand reputation.
Maybe with all of the digital goodies instead of analog goodies is too much for the 12 volt system to handle!!!
That is why most cars are moving to a 48V system.
They design to what they think they need, then they test.
Most car programs have a big oops missed in the design. All the work is done in CAD with simulations for everything. Then they build the car. Things show up when the car is moved to different environments that do not show up in simulation or even initial testing.
The last Liberty/Nitro was designed to use a composite horse collar instead of a metal one. All the simulation said it would work. Prototypes built here in Michigan in the winter passed testing with flying colors. Then they took them to the desert and it turned into a limp noodle in thge heat. The whole car was designed, it was done and the fix was ridiculous.
^^^ If GM's motivation was to leak a delay to get those on the fence to buy a C7 to reduce existing stock rather than wait for the ME, it worked in your case.
My C7 was my dealers first allocation in 2013,I reserved it in 2012.
Same with the C8...I’m getting his first allocation.
I,personally, don’t like buying a car model that’s about to change generation.
We all see value differently .
My "guess" is they have implemented Start/Stop which requires and electric water pump and other issues. May even have tried to implement what we have in the wife's BMW SUV a simple form of braking energy recovery that only charges the battery when braking or coasting. The BMW has an additional AMG battery that is used with that system. In her prior X5 SUV there was a recall an they replaced that battery with a higher capacity AMG because of unanticipated use issues! Of interest they use the two 12 volt batteries in series for the electric steering to cut the peak current draw in half. The Vette can use >100 amps in peak transient current.
Just my speculation that something other than normal electrical issues caused the problem. Don't think they could have used an F1 KERS type system just yet!
Electrical power requirements have been dropping over the years. Modern digital circuits require lower voltages and consume less amps. So, even though modern cars have more electronic components, they have not added much to the electrical load. Minor exceptions might be servo motors to change shock settings (orifice based) , change ride height, etc. As mentioned previously, the big gotcha would be the impact of the wiring to support hybrid operation.
Since the hybrid version of the Corvette is years away, I would hope that they would use a separate or an additional wiring harness for it. My guess would be that that the control signals for hybrid operation would be integrated into the current buss structure; whereas, the heavier gauge wiring for the battery / motor connections would be separate.
Yeah, but there are other systems such as electric motor power steering, air, stop start systems, turbo anti lag motors, etc. that could use a separate 48v system, GM has close ties with German companies and the major one is Siemans. GM uses their NX Soft ware systems and probably investigating their 2 tier voltage auto systems like they did with ZF. .Battery technology is the biggest obstacle. Lead acid is very stable but heavy.
In 96, the introductory paper "Bordnetzarchitektur im Jahr 2005" (Automotive electrical system architecture for the year 2005) was agreed, and on June 4, 1996, BMW presented the "Tabelle heutiger und zukünftiger Verbraucher im Kfz" (Table of present and future loads in the motor vehicle) and the "42V/14V-Bordnetz" (42V/14V PowerNet).
At the 7th International Technical Meeting for Vehicle Electronics in Baden-Baden in the same year, considerable interest was raised by the paper "Neue Bordnetz- Architektur und Konsequenzen" (New Automotive Electrical System Architecture and Consequences), presented by Dr. Richard D. Tabors (MIT).BMW presented the "Spezifikationsentwurf für das Zwei-Spannungsbordnetz 42V/14V" (Draft Specification of a Dual Voltage Vehicle Electrical Power System 42V/14V) in Hanover.
The work at SICAN GmbH was given decisive impetus by the cooperation between BMW and Daimler-Benz as witnessed in their joint definition of the European "Load List 2005" and the jointly authored "Draft Specification of a Dual Voltage Vehicle Electrical Power System 42V/14V".
In intensive discussions with the major semiconductor manufacturers, a voltage of approximately 40 V was found to be advantageous. Many arguments are summarised in the paper "Intelligente Leistungshalbleiter für zukünftige Kfz-Bordnetze" ("Intelligent Power Semiconductors for Future Automotive Electrical Systems" presented by the former Siemens Semiconductors at the 17th "Elektronik im Kraftfahrzeug" (In-Car Electronics) conference in Munich 97.
Other arguments for a higher voltage included the reduction of weight in the wiring system, improved stability, and reduced voltage drop With three times the voltage, thick conductors can be reduced to a third of the cross-section, and at the same time the relative voltage drop can also be reduced to a third. For the same cross-section, the relative voltage drop is now no more than one ninth. The voltage level resulting from these arguments was so close to three times the present voltage that 42 V became the automatic choice for the second voltage level.
You can spend a lot of time searching this stuff. German car electrics are very unreliable right now, but a break through must be on the horizon and GM must be in the loop
.In 2011, several German car makers agreed on a 48V on-board electric power supply network supplementing the current 12V network and introduced the "Combo plug", a common power plug for DC charging electric vehicles. As of 2018, this 48 volt electrical system has been applied in production vehicles such as Porsche and Bentley SUVs, and Volvo and Audi plan to use the 48-volt standard in 2019 vehicles.
I was horrified when GM used German technology in their Caddy 'Hot V' engine and Toyota using a complete Mercedes chassis in their Supra. Maybe the C8 has rear wheel steering like the MB GT which is coupled electronically to the front steering via wires and electric motors. Maybe they have this German system.
engineers have uncovered a major electrical issue with the future Corvette during the development process. From what we gather, the vehicle’s electrical system can’t carry the load necessary to support the necessary components.
As an Electrical Engineer for avionics systems, I find that highly unlikely. One of the very first things a design team does, is to capture the electrical load requirements and then design in enough margin to operate in extreme conditions, temperature ranges and corner cases.
As an Electrical Engineer for avionics systems, I find that highly unlikely. One of the very first things a design team does, is to capture the electrical load requirements and then design in enough margin to operate in extreme conditions, temperature ranges and corner cases.
Could it be something else though? Not just a load requirement, but something to do with interference or systems communication (I only know the very basics of how to wire a race car and do basic house stuff w/o killing myself). If the car has start/stop crap, electric steering, electric AC and water pump and the new super rolling key encryption... is there something in all that that could go amiss under some unique condition and not just simply be a load issue?
Certainly you can question how and why, but one only has to look at other projects like Hubble or Mars Climate Orbiter to see $h!t happens. W/ all the electronics crammed in today's cars, I'm surprised this hasen't happened with other earlier vehicles.
As long as it's corrected before the car hits the market, I'm good. I can't imagine the negative impact the C8 would get if cars would fail to start or worse. One only has to think of the bad press and wide news coverage BMW received when a few vehicles (out or thousands sold) caught fire while parked.
On a side note, I hope GM figures out a way to ditch the traditional heavy and large lead-acid battery in the Corvette with some type of cutting-edge Lithium-Ion/capacitor combo battery that is smaller and lighter.
Last edited by ArmchairArchitect; 12-13-2018 at 10:18 AM.
So, someone at GM tells GMauthority.com that the car that hasn't been announced or acknowledge yet..... is delayed because of electrical problems? That would be a pretty risky leak....if true!
Bingo! No way GM discussed a issue about a car that they do not even acknowledge is in the pipe line.
GM standard answer is we DO NOT DISCUSS POSSIBLE FUTURE PRODUCTS.
Everyone on the forum always states they cannot reveal their source for information .
So does anyone really believe that a GM employee would acknowledge that their are developmental issue with the future unannounced flagship?
I say no way if they risk their job just acknowledging the car is in the pipe line they definitely get fired for discussion of issue with this unacknowledged future car.
We been hearing the faster version of the ME will have electronic motors, simular to other electric cars. In order for GM to keep cost in line they need an electric system to handle all versions.
I dunno, that doesn't make sense to me. Why have the heavy (and expensive) wiring to support electric motors on a version that does not have electric motors?
Bingo! No way GM discussed a issue about a car that they do not even acknowledge is in the pipe line.
GM standard answer is we DO NOT DISCUSS POSSIBLE FUTURE PRODUCTS.
Everyone on the forum always states they cannot reveal their source for information .
So does anyone really believe that a GM employee would acknowledge that their are developmental issue with the future unannounced flagship?
I say no way if they risk their job just acknowledging the car is in the pipe line they definitely get fired for discussion of issue with this unacknowledged future car.
Just like the CAD leaks, the paint shop photos, etc...
at this phase all the testing ting done on the car is for durability purposes. Something BROKE after a period of operation. Whether it’s electrical or mechanical is up for debate, nothing on the car now, during this phase of testing, would have been found to “can’t handle the load.”
Anecdote time. The company I worked for used to supply parts to a Tier One that supplies to GM (*cough* Hurst Shifters on the Camaro *cough*). We designed the part in collaboration with GM, and in durability testing they found that one of the bushings inside the mechanism would fail after about a million shifts. The part fit fine, operated fine, we had actually placed a 7 figure order for parts when they came back and said “um, no. Scrap that purchase order.”
We had to reorder a higher durometer bushing, mad rush the assembly, scrap a container full of parts, and re-do our durability testing and document to show that the bushing will last well past the LIFETIME of the car they’re installed in. It was a pain in our butts, and as the car was already rolling off the assembly line it was high hell to pay on our end.
But sh*t like this actually happens more often than not, especially during the end stages of development and testing. Stuff that worked fine as specified ended up breaking during durability testing.
at this phase all the testing ting done on the car is for durability purposes. Something BROKE after a period of operation. Whether it’s electrical or mechanical is up for debate, nothing on the car now, during this phase of testing, would have been found to “can’t handle the load.”
Anecdote time. The company I worked for used to supply parts to a Tier One that supplies to GM (*cough* Hurst Shifters on the Camaro *cough*). We designed the part in collaboration with GM, and in durability testing they found that one of the bushings inside the mechanism would fail after about a million shifts. The part fit fine, operated fine, we had actually placed a 7 figure order for parts when they came back and said “um, no. Scrap that purchase order.”
We had to reorder a higher durometer bushing, mad rush the assembly, scrap a container full of parts, and re-do our durability testing and document to show that the bushing will last well past the LIFETIME of the car they’re installed in. It was a pain in our butts, and as the car was already rolling off the assembly line it was high hell to pay on our end.
But sh*t like this actually happens more often than not, especially during the end stages of development and testing. Stuff that worked fine as specified ended up breaking during durability testing.
12-13-2018, 08:13 AM
