Is the automatic transmission in the Z06 that bad?
06-16-2018, 02:00 PM
#21
Team Owner
The A8 in "M" mode is not faster than the M7. Only off the line is the A8 faster than the M7! Then only in "D" I own both rigs I know!
The A8 in manual mode is a not an instant shift. Keep exposing your lack of driving skills and knowledge.
Last edited by 3 Z06ZR1; 06-16-2018 at 02:02 PM.
06-16-2018, 03:10 PM
#23
Melting Slicks
More comment from the peanut section! The A8 in "M" mode is not faster than the M7. Only off the line is the A8 faster than the M7!
Then only in "D" I own both rigs I know!
The A8 in manual mode is a not an instant shift. Keep exposing your lack of driving skills and knowledge.
The A8 in "M" mode is not faster than the M7. Only off the line is the A8 faster than the M7! Then only in "D" I own both rigs I know!
The A8 in manual mode is a not an instant shift. Keep exposing your lack of driving skills and knowledge.
It was repeatedly stated by GM, and various hotshoe drivers when the car was released, that the A8 is also faster than the M7 on most road courses. That however only happens for the first 2-3 laps until the engine overheats and pulls power/goes into limp mode due to inadequate cooling. Hence the M7 actually turns out to be ‘faster’ on a road course, since if you want to run the full, normal HPDE session in an A8 car, you have to short shift, which in turn makes it slower over the course of 20-25 minutes.
Bish
06-16-2018, 04:19 PM
#24
Le Mans Master
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Perhaps you don't realize yet that owning something is not synonymous with knowledge. Ask The Queen for technical details on her Rolls Royces or Bentleys.
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06-16-2018, 04:26 PM
#25
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The A8 is faster up until the 4th to 5th gear shift than the M7, at which time due to gearing, the M7 starts to pull harder. Hence on a 1/4 mile strip the A8 wins.
It was repeatedly stated by GM, and various hotshoe drivers when the car was released, that the A8 is also faster than the M7 on most road courses. That however only happens for the first 2-3 laps until the engine overheats and pulls power/goes into limp mode due to inadequate cooling. Hence the M7 actually turns out to be ‘faster’ on a road course, since if you want to run the full, normal HPDE session in an A8 car, you have to short shift, which in turn makes it slower over the course of 20-25 minutes.
Bish
It was repeatedly stated by GM, and various hotshoe drivers when the car was released, that the A8 is also faster than the M7 on most road courses. That however only happens for the first 2-3 laps until the engine overheats and pulls power/goes into limp mode due to inadequate cooling. Hence the M7 actually turns out to be ‘faster’ on a road course, since if you want to run the full, normal HPDE session in an A8 car, you have to short shift, which in turn makes it slower over the course of 20-25 minutes.
Bish
Last edited by Warp Factor; 06-16-2018 at 04:26 PM.
06-16-2018, 04:42 PM
#26
Heel & Toe
Thread Starter
Mine has been fine (2016 Z06, March 2016 build).
I have a Range anti-AFM module in mine so it never goes into V4 mode whether it is in automatic or manual. You will see a lot of torque converter issues with the 8L90 (aka A8) transmissions in multiple platforms because of what GM does with the powertrain control in V4 mode. Operating on half its native number of cylinders there is not surprisingly a lot more engine vibration and in V4 mode the converter lock up clutch is continuously modulated on and off between its locked and unlocked states to allow the torque converter to absorb some of the vibration. The downside to this is an obvious increase in wear that occurs from continuous cycling of the clutch. Ultimately this results in RPM variation at steady cruising speed due to lockup clutch wear progressing to shudder (feels like the vehicle is running over rumble strips) as the wear gets worse.
This is a much bigger problem in non-Z06 Corvettes which spend far more time in V4 mode. Even without a Range module or not driven in manual mode (either of which prevents V4 operation) a Z06 rarely drops into 4 cylinder mode due to its greater wind drag and lower base compression ratio of its supercharged engine. But I am not taking any chances with this poor design choice which was right up there with specifying the same radiator and coolant system capacity for the LT1 and LT4 engines.
The only other advice I have with the 8L90 is at least through 2016 it has an issue with initial slow fill of the C4 clutch pack actuator for the very first 1 to 2 shift of the day. This can result in a harsh initial upshift on the first shift to second but an easy work around is with the car still stationary drop it into manual mode, paddle shift to 2, then either put it back in drive or shift to 1 and drive as you normally would. Once the initial hydraulic actuator fill takes place this won't be an issue again until after parking it overnight. GM may have updated the software by now to do a partial pre-fill of this actuator at initial start but if not this work around is simple and it works fine.
I am very happy with the 8L90 but not pleased that avoiding V4 mode is not user selectable like it is with manual transmission Corvettes or A8 units intended for export. One of the deciding factors for me in replacing my 2006 GMC diesel pickup with another diesel instead of a gas light duty pickup was I don't want anything else with this Rube Goldberg AFM/V4 scheme.
I have a Range anti-AFM module in mine so it never goes into V4 mode whether it is in automatic or manual. You will see a lot of torque converter issues with the 8L90 (aka A8) transmissions in multiple platforms because of what GM does with the powertrain control in V4 mode. Operating on half its native number of cylinders there is not surprisingly a lot more engine vibration and in V4 mode the converter lock up clutch is continuously modulated on and off between its locked and unlocked states to allow the torque converter to absorb some of the vibration. The downside to this is an obvious increase in wear that occurs from continuous cycling of the clutch. Ultimately this results in RPM variation at steady cruising speed due to lockup clutch wear progressing to shudder (feels like the vehicle is running over rumble strips) as the wear gets worse.
This is a much bigger problem in non-Z06 Corvettes which spend far more time in V4 mode. Even without a Range module or not driven in manual mode (either of which prevents V4 operation) a Z06 rarely drops into 4 cylinder mode due to its greater wind drag and lower base compression ratio of its supercharged engine. But I am not taking any chances with this poor design choice which was right up there with specifying the same radiator and coolant system capacity for the LT1 and LT4 engines.
The only other advice I have with the 8L90 is at least through 2016 it has an issue with initial slow fill of the C4 clutch pack actuator for the very first 1 to 2 shift of the day. This can result in a harsh initial upshift on the first shift to second but an easy work around is with the car still stationary drop it into manual mode, paddle shift to 2, then either put it back in drive or shift to 1 and drive as you normally would. Once the initial hydraulic actuator fill takes place this won't be an issue again until after parking it overnight. GM may have updated the software by now to do a partial pre-fill of this actuator at initial start but if not this work around is simple and it works fine.
I am very happy with the 8L90 but not pleased that avoiding V4 mode is not user selectable like it is with manual transmission Corvettes or A8 units intended for export. One of the deciding factors for me in replacing my 2006 GMC diesel pickup with another diesel instead of a gas light duty pickup was I don't want anything else with this Rube Goldberg AFM/V4 scheme.
I spoke with my wife and when the time comes, I will order the manual after all Just not happy to pay so much money for an auto transmission that I need to work with to get the most out of it.
06-16-2018, 05:21 PM
#27
Instructor
After reading through numerous threads I'm sensing a lot of people don't understand/properly shift an automatic in manual mode. Thankfully they are not driving manuals
For putting around in town, just leave it in auto--paddle shifting sucks in traffic or for a grocery run. Light the car up and it will absolutely blast through shifts in auto. For even more fun, hold the downshift paddle while it finds it lowest gear 'quickly' and then hammer it. Downshifting into a hard turn is an absolute blast and burble is sweet (not as sweet as my old Boss 302 quad exhaust) but still a blast.
Too many people are internet experts based on knowledge formed through others vlogs...
And yes, I might still prefer a DCT but not 100% certain on that either. Some Euro brands (BMW) are starting to move away from them so who knows..
Last edited by lupicon; 06-16-2018 at 05:22 PM.
06-16-2018, 05:50 PM
#28
Heel & Toe
Thread Starter
The A8 is faster up until the 4th to 5th gear shift than the M7, at which time due to gearing, the M7 starts to pull harder. Hence on a 1/4 mile strip the A8 wins.
It was repeatedly stated by GM, and various hotshoe drivers when the car was released, that the A8 is also faster than the M7 on most road courses. That however only happens for the first 2-3 laps until the engine overheats and pulls power/goes into limp mode due to inadequate cooling. Hence the M7 actually turns out to be ‘faster’ on a road course, since if you want to run the full, normal HPDE session in an A8 car, you have to short shift, which in turn makes it slower over the course of 20-25 minutes.
Bish
It was repeatedly stated by GM, and various hotshoe drivers when the car was released, that the A8 is also faster than the M7 on most road courses. That however only happens for the first 2-3 laps until the engine overheats and pulls power/goes into limp mode due to inadequate cooling. Hence the M7 actually turns out to be ‘faster’ on a road course, since if you want to run the full, normal HPDE session in an A8 car, you have to short shift, which in turn makes it slower over the course of 20-25 minutes.
Bish
06-16-2018, 05:52 PM
#29
Drifting
06-16-2018, 05:56 PM
#30
Instructor
Yeah it sucks. And it sucks in a manual too. Not sure about traffic in Mesa, but its pretty much LA quality here in Toronto so my point is the slow clicking so many whine about may be more prevalent when you are are going from between 10-30mph for a few hours. I personally don't see the point of not driving in auto when in stop and go, but you apparently do so enjoy yourself.
Last edited by lupicon; 06-16-2018 at 05:59 PM.
06-16-2018, 06:12 PM
#31
This jack off is a brit okay, probably paid to do this,
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
Its great, forget this monster.
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
Its great, forget this monster.
06-16-2018, 06:25 PM
#32
Le Mans Master
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This jack off is a brit okay, probably paid to do this,
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
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pkincy (06-18-2018)
06-16-2018, 06:30 PM
#34
Heel & Toe
Thread Starter
This jack off is a brit okay, probably paid to do this,
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
Its great, forget this monster.
I have 22k on my A8, including track time and I do not have this annoying sound, yes you hear click, but I find that helpful knowing I've communicated to the transmission I want another gear. And its immediate. Hold it down for continued shifts.
Its great, forget this monster.
In my previous 2018 M4 Convertible, let's say I was cruising on 7th gear at 120KM/H, if I mash the gas to the kick down point then do a single downshift via the shift paddle, the car automatically chooses the lowest gear for you for that speed to give you the max acceleration so it would immediately drop down from 7th to 3rd then I'm in control. It had a DCT transmission so not sure if the Automatic tranny in the Corvette does this? how do you get the best acceleration in the above scenario if you were just cruising around and suddenly wanted to smoke someone?
06-17-2018, 10:06 AM
#37
Le Mans Master
I can't watch the video because it's probably some clueless millennial whining about some feature on an expensive car, which is half of YouTube these days.
I'll just say that if selecting your own ratio is an important part of driving for you, get the M7, because paddle shifting the A8 isn't much fun.
I maintain the car is fast enough that you're busy enough shifting gears belongs back in the 60s with a Muncie. So I drive an A8. But if you like changing gears for some reason, don't think the A8's paddles will do it for you.
I'll just say that if selecting your own ratio is an important part of driving for you, get the M7, because paddle shifting the A8 isn't much fun.
I maintain the car is fast enough that you're busy enough shifting gears belongs back in the 60s with a Muncie. So I drive an A8. But if you like changing gears for some reason, don't think the A8's paddles will do it for you.
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06-18-2018, 11:36 AM
#38
Safety Car
I came to the forums trying to figure out whether to go M7 or A8 before ordering mine. The best thing I read was if you can test drive each. Well I found a dealership willing to let me test drive each. I took the A8 out came back and told him I no longer needed to test the manual because I won’t be getting it an auto. Again, just all comes down to personal preference. Same thing with the competition seats, so glad I sat in them before ordering them just because they look cool.
Also I seldom leave it in drive. Why? D keeps the car in the high teens rpm wise and I prefer the car to be mid 2000s simply for better torque and responsiveness even while simply going to the store. I seldom drove my C5Z or my C6Z in 6th so why would I drive my C7Z in 7th or 8th? And that is where leaving it in D will put you even with a 50-55 mph speed limit road. So I drive with both hands on the wheel at 10 and 2 and shift with a finger tip.
A Q for the M7 folks: Do you keep the car at 1500-1700 rpm while you are shifting? My guess is you do not. The car is just better when it is constantly in its torque band. If I want to accelerate with any transmission I don't want to wait to catch a gear to go forward, be it manual or automatic. Costs me some gas money but makes the car much more fun. Also with the SC and 650 ft lbs of torque you don't need to downshift if you want to make a quick pass so long as you are at 2500 rpm or so. The car will just jump forward. So I drive the A8 the same way I did all my manuals (ZF6, TR6, TR6060), with the car in a proper gear for what was happening or might be happening all the time. I only use the single paddle pull to go down multiple gears when I am approaching a stop light/sign and that is simply to hear those wonderful down shifts and make every body around me jealous.
Last edited by pkincy; 06-18-2018 at 11:44 AM.
06-18-2018, 11:49 AM
#39
Le Mans Master
Here's a great answer from Tadge on the paddle shift reaction time, pay very close attention to the last paragraph.
https://www.corvetteforum.com/forums...tion-time.html
https://www.corvetteforum.com/forums...tion-time.html
06-18-2018, 12:08 PM
#40
Melting Slicks
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I personally have had my 18 z06 2lz auto for over 5 months and its my only car and daily driver and I drive it very aggressively. In my opinion its best to leave the car in drive and sport mode and just pretend the paddle shifters dont even exist. You want to go fast just get on the gas. The car does exactly when it is supposed to do and a indicator comes on saying "Performance Shift Active". I get way better performance that way than using the paddles
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Super Spartan (06-19-2018)