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Doing 0-60 times 2020 C8. In LC revs to 3500, bogs a little at first, 1/ 2 shift it hits limiter almost shuts down , picks back up and goes. Is there a setting on limiter that can be adjusted or reset? Does it more often than not. Any suggestions. Car is in shop and so far no solid answers . Tks in advance
Doing 0-60 times 2020 C8. In LC revs to 3500, bogs a little at first, 1/ 2 shift it hits limiter almost shuts down , picks back up and goes. Is there a setting on limiter that can be adjusted or reset? Does it more often than not. Any suggestions. Car is in shop and so far no solid answers . Tks in advance
Don't try to manual shift from 1-2. The human body isn't fast enough to hit 6500 without hitting the limter.
Also make sure you're in competitive traction mode or ptm sport to avoid bogging
In the Service Manual its called "Engine Overspeed Protection". I could not find any indication that it can be adjusted. But...if its getting the limit and stopping the engine, that is what you want, right? Unless you are suggesting that on yours, the "limit" is incorrectly set low? What RPM do you see when it "cuts out"?
It’s in auto..And everything is in right right spot
If its on auto (trans in track mode) and your esc/tc is set up correctly it should be shifting correctly. Sometimes massive wheel spin can confuse the dct but that would be noticable.
Check for any softcodes. Otherwise you may have to wait for one to show up. If you're doing high g launching on prepped surface consider adding the 2 quarts
I can see it doing it if I was in manual mode, that’s on me but this in auto mode and it shouldn’t hitting it. That’s set at the factory. So my question is what’s causing it now. It wasn’t doing it before . What controls this. The tech is talking with the GM tech and no progress as yet. I wonder if the ECU is the culprit ?
The TCU controls most like shift points, clutch engagement and pressure etc but the ECU gives preparatory commands and controls timing during shifts. Its symbiotic
If you are hitting the rev limiter in automatic shift mode then something is wrong. I think a dealer/master Corvette mechanic is in your future (at least to diagnose the problem).
the tech and the tech from GM were back and forth yesterday on phone. GM tech had nothing really. im gathering the posts on here and relay them back. at least i have a case started. Im leaning toward what your saying. ive got it on the PDR . i should just give to them and they can take a look get a better idea.
^^^
I agree, something wrong! I hit the Rev Limiter several time when I first got the C8. Was driving in Manual Mode for the 1st month (getting over ~60 years of every DD being a standard shift.) BUT I leave a stop sign at the end of my rural road and merge into often heavy traffic going ~70 mph on a 4 lane divided highway. After accelerating at WOT the upshift paddle is out of postilion with the steering wheel turned and a few times hit the Rev Limiter in 1st. Heck it's at the ~35 mph Redline in the blink of an eye! Like throwing out an anchor! Until you pull the upshift paddle fuel is not being delivered to the engine! Doesn't sound like you are experiencing that it is shifting itself.
I now use Z Mode (and have for the past two years.) Have a ~3/4 mile rural road near the house with only farm fields both sides, no traffic. When I turn onto that road from a stop often use WOT just for fun. It shifts just fine out of 1st, 2nd and 3rd. Never hesitation at the shift points.
If your in manual mode that’s on you hitting limiter . I’m talking automatic. Btw you can’t shift as fast as the auto. I’m not being a smart *** here either Lol
^^^ As I said, was in Manual Mode and 2 years ago switched to Z Mode. Even with 60+ years experience "stirring a stick" and many speed shifts (in my younger days without a clutch) no way can anyone match what I have fun doing when I turn onto rural roads near my home from ~70 mph traffic.
Pic makes it clear. In Z Mode (Power set to Track) with aggressive braking it downshifts ~3+ gears in the blink of an eye. Rev matching each.
Could be. Note the OP lives in NY! Tires don't have the same traction when they get cold. How Cold?
An example is my Street Rod with 16.5 section width (420 metric) Mickey Thompsons, 53% of its ~3000lb on the rear, 4 bar link rear suspension set with instant center in front of the car for max weight transfer and heavy battery in the far-right rear with adjustable coilovers set for even right left load.
Below ~70 F don't even try for max "g" off the line!
8.2 Liter BB set back in tubbed chassis provides 53% weight on rear. Need ~70+ F temps before trying max acceleration off the line!
I am thinking through what could allow you to hit the limiter and only a couple things come to mind:
1) wheels are spinning (you would probably notice that though)
2) clutch pack is slipping, or eLSD is slipping (big question then is WHY is it slipping? Solenoid problem? Pump pressure problem? You'd think there would be a sensor there for that...)
3) sensor is giving faulty data somewhere. It's a complex setup where the TCM actually "drives the car". When you hit the gas pedal, you send that input to the TCM. The TCM then decides what is do-able and sends commands to the ECM that controls the throttle body. As someone else pointed out, it is a very symbiotic setup. The performance envelope of the car is really fully controlled by the DCT which is why I think it is interesting that the MC20 with the same TR9080 has relatively close performance specs until you get into the higher gears where the TT V6 has more HP than the LT2. Clearly it is the DCT that is the limiting factor there.
Limiter
As I said, was in Manual Mode and 2 years ago switched to Z Mode. Even with 60+ years experience "stirring a stick" and many speed shifts (in my younger days without a clutch) no way can anyone match what I have fun doing when I turn onto rural roads near my home from ~70 mph traffic.
Could be. Note the OP lives in NY! Tires don't have the same traction when they get cold. How Cold?
