2020 C8 Corvette Stringray

[alienviking]

I'd drive that.

[Chris GTO TT]

Having seen a few of them around here I wouldn't kick it out of my garage, but I don't think I'd buy it based on looks alone.

[Jeff V.]

New red. Looks like they did their own version of that beautiful red Mazda has.




Funny story. Vira and I went down to the lake for a day. We got pizza, and the young girl who brought our order out asked what year my car was. I told her, and she said it looked like the 2020, even though the proportions were different.

[Chris GTO TT]

I'm surprised it's taken this long for other Mfg to come out with a similar color to Mazda Soul Red

[aaronatstate]

That red is nice.

Also, I've seen a few people on YouTube slapping twin turbo kits on C8s. They are all running like 2 or 3 lbs. of boost, because there is no way to tune the ECU. The one girl, running 3 lbs. her transmission wouldn't shift because of the excessive torque it was now making.

They keep talking about how they'll be able to tune it eventually, has there been any progress made on being able to tune them?

[Jeff V.]

I haven't seen anyone provide real details on the tuning situation. I've seen some shops talk in vague terms about piggybacks, but nothing specific. It's all wishful thinking right now. There's one guy who upgraded his cats (I guess he still thinks this is the 80s) and his car freaked out. I don't know how turbos could work at all in the real world.


I think the only thing anyone is actually tuning at this point are their YouTube and Instagram stats.

[mjannusch]

I like the Silver Flare color. That photo makes it look really nice.

I don't think the C8 is going to be anywhere near as easy to tune as the previous generations due to all the encryption and locking in the ECUs now. All the systems are so integrated with each other, even if you can tune it - figuring it all out to run and shift well is going to be a nightmare.

If someone has to have more power, I'd just wait for the Z06/ZR1/Zora or whatever.

[aaronatstate]

[quote=""Jeff V.""]I haven't seen anyone provide real details on the tuning situation. I've seen some shops talk in vague terms about piggybacks, but nothing specific. It's all wishful thinking right now. There's one guy who upgraded his cats (I guess he still thinks this is the 80s) and his car freaked out. I don't know how turbos could work at all in the real world.


I think the only thing anyone is actually tuning at this point are their YouTube and Instagram stats.[/quote]

Yeah basically they added 2 big turbos making 2-3 psi of boost, and the ECU can compensate for it, but only so much. If if it's anything like Ford's ECU tuning, and tuned to a specific torque, once the ECU relearns what is happening with regards to torque it'll change other parameters to maintain that torque. That's why it is useless to get an exhaust or intake for my RS, unless I get an Accessport to go with it.

[Jeff V.]

From what I've read, the DCT is only good for 550ish lbs of torque anyway, so tuning is just the first hurdle. One of the shops snapped off an axle with a modest shot of nitrous. That doesn't bode well either.

[aaronatstate]

[quote=""Jeff V.""]From what I've read, the DCT is only good for 550ish lbs of torque anyway, so tuning is just the first hurdle. One of the shops snapped off an axle with a modest shot of nitrous. That doesn't bode well either.[/quote]

Nope not at all. But Tremec has to be working on beefing it up to support the higher hp variants that are coming. I mean Tremec makes the trans for the GT500 and it's rated to 660 ft. lbs., so they definitely can beef it up. What that takes though, I have no idea...

Also, the 2 YouTubers I've watched have been saying in their videos "once we figure out how to tune it", I don't know if they'll get there...

[Jeff V.]

It's funny. LMR in Texas built StreetSpeed717s car. People in the thread were asking about tuning and heat management and longevity and all I could do was laugh at those suckers. He doesn't care. He's getting his YouTube revenue now and he's gonna flip that car the second he can take delivery of a Z06, or whatever other hot-at-the-moment car is available when his clicks start to decline.

I'm sure LMR does nice work, but I think the only design consideration on that car was "put two giant turbos on top where you can see em".

[aaronatstate]

[quote=""Jeff V.""]It's funny. LMR in Texas built StreetSpeed717s car. People in the thread were asking about tuning and heat management and longevity and all I could do was laugh at those suckers. He doesn't care. He's getting his YouTube revenue now and he's gonna flip that car the second he can take delivery of a Z06, or whatever other hot-at-the-moment car is available when his clicks start to decline.

I'm sure LMR does nice work, but I think the only design consideration on that car was "put two giant turbos on top where you can see em".

[/quote]

StreetSpeed717s car is one of the ones I was referring to actually. I think he said they are putting turbo blankets and wrapping the exhaust for heat control, that it just hadn't been done yet. It was on LMRs YouTube where they went more in depth about the build.

Edit: YouTube video

[mjannusch]

So dumb when you can't even do a basic tune on it.

Is the whole canbus encrypted on this thing, so you couldn't even intercept parameters and modify them on the wire?

[aaronatstate]

[quote=""mjannusch""]So dumb when you can't even do a basic tune on it.

Is the whole canbus encrypted on this thing, so you couldn't even intercept parameters and modify them on the wire?[/quote]

That's everyone's hope from the videos I watched is basically put a piggy back on it. Problem is the ECUs are smart enough now to know a value isn't right based off other values it's getting. And then you run into issues like the fact it is probably calculating the torque it is making based off of engine parameters and cutting power, not letting the trans shift because of high torque. There is no torque input to fool with a piggy back.

[Jeff V.]

I wish I knew. I've been hunting all over for some kind of detail on what they changed, but I can't find a damn thing. Not from GM or anywhere else.

The only thing I know for sure is they implemented a gateway module. They actually started that in 2017 on the C7. Dunno what year it started on other cars. It's basically a firewall that blocks traffic between different CANbus domains, as well as between the CANbus and the outside world via the OBD port and the OnStar and wifi interfaces.

Then on the ZR1 they went with the new E99 ECM. That had a chain of crypto certificates that was burned into the main CPU. The CPU won't run software that's not signed with keys known only to GM. The HP Tuners fix is to remove the CPU and replace it with one that has keys they know. The downside is now you're locked into HP Tuners for everything since they hold the secret keys instead of GM. That also means GM is locked out and it's an obvious red flag your car has been modified.

My guess for the new Global B system is they implemented crypto keys between the modules. The Germans have been doing something similar for a long time now. My Audi had component protection, which was the same concept. Basically certain modules trust each other based on the presence of those keys. So the E99 trick from the ZR1 won't work because now let's say the fuel pump module, trans module, and gateway module all go into lockdown because they no longer trust the ECM.

As far as actually encrypting the bus data between the modules, I have no idea. Thanks to the gateway, now you need to actually tap the bus somewhere else in the car to sniff it. You can't just plug into the OBD port since the gateway only allows diagnostic data on that.

Let's put it this way. I've been working on and off for roughly two years now just to figure out how to re-enable one menu I lost when I upgraded the HMI on my C7. My car has a simpler set of buses, uses no encryption, I've got all the GM service tools and a leaked set of signal definition files. I still can't figure it out. This shit is hard. GM has made it exponentially harder over the last few years.

If GM did their job right, nobody is getting into this car's electronics. As Aaron said, even piggybacks may not work. These cars basically have physics models for their operating parameters. It can read from things like the ABS and airbag accelerometers to know it's going way too fast for 'only' 500 lbs of torque, for example.

[aaronatstate]

[quote=""Jeff V.""]I wish I knew. I've been hunting all over for some kind of detail on what they changed, but I can't find a damn thing. Not from GM or anywhere else.

The only thing I know for sure is they implemented a gateway module. They actually started that in 2017 on the C7. Dunno what year it started on other cars. It's basically a firewall that blocks traffic between different CANbus domains, as well as between the CANbus and the outside world via the OBD port and the OnStar and wifi interfaces.

Then on the ZR1 they went with the new E99 ECM. That had a chain of crypto certificates that was burned into the main CPU. The CPU won't run software that's not signed with keys known only to GM. The HP Tuners fix is to remove the CPU and replace it with one that has keys they know. The downside is now you're locked into HP Tuners for everything since they hold the secret keys instead of GM. That also means GM is locked out and it's an obvious red flag your car has been modified.

My guess for the new Global B system is they implemented crypto keys between the modules. The Germans have been doing something similar for a long time now. My Audi had component protection, which was the same concept. Basically certain modules trust each other based on the presence of those keys. So the E99 trick from the ZR1 won't work because now let's say the fuel pump module, trans module, and gateway module all go into lockdown because they no longer trust the ECM.

As far as actually encrypting the bus data between the modules, I have no idea. Thanks to the gateway, now you need to actually tap the bus somewhere else in the car to sniff it. You can't just plug into the OBD port since the gateway only allows diagnostic data on that.

Let's put it this way. I've been working on and off for roughly two years now just to figure out how to re-enable one menu I lost when I upgraded the HMI on my C7. My car has a simpler set of buses, uses no encryption, I've got all the GM service tools and a leaked set of signal definition files. I still can't figure it out. This shit is hard. GM has made it exponentially harder over the last few years.

If GM did their job right, nobody is getting into this car's electronics. As Aaron said, even piggybacks may not work. These cars basically have physics models for their operating parameters. It can read from things like the ABS and airbag accelerometers to know it's going way too fast for 'only' 500 lbs of torque, for example.[/quote]

Or completely rip out all the of electronics in the car, and move everything to stand alone, but I feel that would be severely cost prohibitive.

I'm still holding out hope that GM at some point makes a deal with say HP Tuners, to allow their software to tune the vehicle, but it flags it automatically on GMs site, and voids your warranty instantly, and absolves GM of any and all issues you may have with the car from that point on.

[Jeff V.]

This is the closest I've come to a technical definition of the new network.

https://gm-techlink.com/?p=12167

The Next Generation Digital Vehicle Platform powers a new electronic system that is capable of managing up to 4.5 terabytes of data processing power per hour, which is a fivefold increase in capability over the current Global A electrical architecture. The new architecture provides more rapid communications within the vehicle itself as well as to outside sources with Ethernet connections of 100Mbs, 1Gpbs and 10Gbps.

The system features the Controller Area Network with Flexible Data-Rate (CAN FD) protocol, which supports improved data communication and faster programming by transmitting and receiving data at a higher maximum bit rate. A faster bit-rate allows more data to fit into a single message, reducing the need for more networks (and additional wiring) in a vehicle, which also reduces weight and increases performance.



CAN Communication

The Next Generation Digital Vehicle Platform can incorporate up to nine high-speed CAN buses. Low-speed GMLAN and MOST are not used.

Programming and scan tool data information is provided using CAN buses 6 and 7, which only run between the DLC and the Serial Data Gateway Module, and are used by GDS 2 to provide system data from the other CAN networks. This design isolates the remaining buses to secure those networks and provide enhanced intrusion detection incorporated at the architectural level.

The powertrain CAN bus communicates over a dedicated circuit but the other CAN buses use a wake-up message from the Serial Data Gateway Module, which can be tailored to wake up individual modules when needed. The Serial Data Gateway Module is updated first during programming and then any other modules are programmed through the Serial Data Gateway Module.

Or completely rip out all the of electronics in the car, and move everything to stand alone, but I feel that would be severely cost prohibitive.

I'm still holding out hope that GM at some point makes a deal with say HP Tuners, to allow their software to tune the vehicle, but it flags it automatically on GMs site, and voids your warranty instantly, and absolves GM of any and all issues you may have with the car from that point on.

Everything is too inter-connected. It won't happen. I think Rob Dahm is in for a rude awakening when he tries to get his rotary C8 working.

I doubt GM will strike a deal with anyone unless it's a canned, EPA/CARB approved tune. This whole thing started because EPA finally stopped ignoring all the wink wink nudge nudge "off road use only" bullshit. Thank you VW and coal rolling bros. That and connected vehicle intrusion protection.

[mjannusch]

[quote=""aaronatstate""]I'm still holding out hope that GM at some point makes a deal with say HP Tuners, to allow their software to tune the vehicle, but it flags it automatically on GMs site, and voids your warranty instantly, and absolves GM of any and all issues you may have with the car from that point on.[/quote]
I'd be game to do that when the powertrain warranty is almost up anyways. They are going to need to do something to allow module swaps by non-dealers at some point or people are going to be pissed that only the dealer can fix their car (and basically charge whatever they want).

I wonder how John Deere's lawsuits have been going regarding their systems that lock out farmers from maintaining their own implements. Whatever happens in the courts there will probably bleed over to automotive.

[mjannusch]

[quote=""Jeff V.""]Everything is too inter-connected. It won't happen. I think Rob Dahm is in for a rude awakening when he tries to get his rotary C8 working.[/quote]
I'm sure the DCT is going to tell him to go get fucked.

[Jeff V.]

I'd be game to do that when the powertrain warranty is almost up anyways. They are going to need to do something to allow module swaps by non-dealers at some point or people are going to be pissed that only the dealer can fix their car (and basically charge whatever they want).

GM lets any idiot subscribe to their programming and diagnostic tools. Case in point: Me.

I've got two SPS subscriptions. One for my car, and one for the burnt out 2016 wreck that I used to program my electronic upgrades.

It's $40 per VIN for two years. The GDS2 diagnostic software is a little more expensive, but it's not locked to a single VIN.