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The New Car Fanatic Thread


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8 hours ago, PittsburghTiger said:

I've been lucky enough to tour three different factories, two Mercedes and one Audi. I have not been to Porsche for that, although I have been to the old museums for both Porsche and Mercedes. I need to go to the new ones.

The factory tours in person are amazing because you really get a good idea of the scale of precision needed to make cars today. On the same line, one after the other, you could have a right-hand drive car followed by a left-hand drive car, and think nothing of the massive differences involved.

You should tour a heavy equipment factory sometime. They roll wildly different machines down the same lines.

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https://www.motorauthority.com/news/1126213_2022-porsche-911-sport-classic-spy-shots-and-video

 

Porsche launched a new 911 Turbo for 2021 based on the latest 992 generation of its sports car icon. The car is wider than ever and boasts a newly developed flat-6 which in Turbo S grade spits out 640 hp. The car is brilliant, whether it's a docile drive or to the limit at a track.

These latest spy shots and video show what appear to be some of the original prototypes for the 911 Turbo but if you look a little closer you'll notice that these new testers are missing side vents and are instead marked by a prominent ducktail spoiler. The spoiler even has its own reflector, which the spoiler on the regular Turbo skips.

 

 

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On 4/21/2021 at 2:20 PM, Chewbacca said:

Thanks.  Haven't gotten out to drive anything yet (it's still fucking snowing in Denver.  I'm ready for winter to end), but I think I'm leaning towards a C2S - don't want a base.  I won't be driving it in the winter so I don't care about AWD.  I have 2 Landcruisers for that.   On the lower end 991s, I've read some reviews that the turbo lag is annoying because the NA engines just go.  

My S6 has a DCT and it's fast but relatively boring.  I almost never use the paddle shifters.  But the wife can't drive stick and I think if I got this car and she can't drive it, she'll be pissed.  Didn't someone here buy a CPO GTS recently and had to have his PDK replaced?

       This is a big factor for me. We currently have stick cars and if they get parked behind anything I am the only one who can move them. Super annoying. I also don't want to row gears in Houston traffic. So PDK it is for me, and I also am looking for a N/A car. I am looking for a more linear power band coupled with how they sound.

Edited by Thatguy
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On 4/22/2021 at 9:00 AM, pepper brooks said:

I have a porche with pdk and one with a manual.  I drove the stick for 14 years as a daily driver.  I now drive the pdk as a daily.  THeir version of the PDK is simply the best transmission in a production car, and yes i have tried the ferrari, lambo and mcclaren versions.  THe porsche unit is the hands down winner here.  If you're going to use the car as a daily get the PDK.  

   The Porsche PDK is heads and shoulders above the other transmissions you listed. Sure the Ferrari is lightning fast, but it's the reliability and intuitiveness where the Porsche PDK shines. When Chewbacca drives it and watches how it jumps down 3 or 4 gears to the perfect gear for you then he will understand. Whoever is writing the tune for those is really really good.

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18 hours ago, Thatguy said:

jumps down 3 or 4 gears to the perfect gear for you

Yeah, no. Literally no box does this, not even the mythical PDK.

 

I'm always amazed at anyone who has paddles and doesn't use them. You are in the wrong gear 100% of the time if you don't.

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13 minutes ago, G650 said:

Yeah, no. Literally no box does this, not even the mythical PDK.

at max aggression ZF8HP will do a direct downshift of 3 gears rather than step down progressively.  itll automatically downshift when youre off throttle and on the brakes for a corner...but ive never driven that angrily and had it jump 3 gears while braking (only 2 at most)

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29 minutes ago, 52-80 said:

at max aggression ZF8HP will do a direct downshift of 3 gears rather than step down progressively.  itll automatically downshift when youre off throttle and on the brakes for a corner...but ive never driven that angrily and had it jump 3 gears while braking (only 2 at most)

I've got a ZF8 in my F85. I think it's probably the best all around box there is. But it's still never in the right gear.

 

Say you are running at 75 mph on the highway, what gear should you be in, 6, 7 or 8?

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24 minutes ago, G650 said:

I've got a ZF8 in my F85. I think it's probably the best all around box there is. But it's still never in the right gear.

 

Say you are running at 75 mph on the highway, what gear should you be in, 6, 7 or 8?

depends how aggressive you are driving and the set mode.  programming of gearbox logic will determine. 

in normal/comfort and you've been cruising at, or slowly accelerating up to 75mph, it'll be 8. 

if you are in sports/sports+, and you've been driving hard, it'll probably settle at 7.  if you were at higher speed and rapidly brake down to 75mph, it'll be at 7th or 6th, and progressively downshifting as you reduce speed.

 

in other words there's a time component to the logic, not just a 1:1 speed:gear mapping. 

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48 minutes ago, 52-80 said:

depends how aggressive you are driving and the set mode.  programming of gearbox logic will determine. 

in normal/comfort and you've been cruising at, or slowly accelerating up to 75mph, it'll be 8. 

if you are in sports/sports+, and you've been driving hard, it'll probably settle at 7.  if you were at higher speed and rapidly brake down to 75mph, it'll be at 7th or 6th, and progressively downshifting as you reduce speed.

 

in other words there's a time component to the logic, not just a 1:1 speed:gear mapping. 

No.

 

Is there a tractor trailer in front of you? Are you uphill or downhill? Are you getting ready to take a high speed exit or a low speed one? These are just three of thousands upon thousands of situations that all require different gear selection.

 

Shifting after input is an issue that can never be overcome. It will always be wrong no matter what, the shift has to come before any change in throttle or speed input.

 

The only way around this is many multiples of cameras and very advanced AI. It is a long shot to happen in our lifetime.

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4 minutes ago, G650 said:

Is there a tractor trailer in front of you? Are you uphill or downhill? Are you getting ready to take a high speed exit or a low speed one?

Doesn't matter.  If your driving intent is for maximum performance (based on your mode selection AND inferred from previous behavior), then shortest gear is the best gear.

Uphill - shortest gear for highest acceleration

Downhill - shortest gear for maximum engine braking

High speed exit or low speed exit - both demands shortest gear for maximum accel and throttle-controlled rotation; progressively upshifting or downshifting as speed changes

There is no magic gear that the car knows 100% of the time.  The point is it can predict what gear is best 95% of the time. 

That's why

  • if you drive in comfort/normal mode, it's not going kick a big downshift if you are braking (whether for turn or any other reason). 
  • If you drive in sport/sport+/race mode, it's going to kick a big downshift if you are braking -- because likely you would do that manually anyway. 

If you are in comfort/normal mode at 75mph, and have been at that constant speed for 5 minutes, and you add 5% throttle to pass, it'll merely drop to 7th or 6th or whatever.  You might have wanted 4th or 5th.  That's not a failure of the machine, that's just based on your change in input.

If instead you had jammed the thottle (triggering kick-down switch), and/or HELD the paddle (rather than single click), it will do a maximum downshift.  Again, that's consistent to your input.

 

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Just now, G650 said:

Again, everything you just wrote before this is irrelevant. It's already too late.

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Say you are running at 75 mph on the highway, what gear should you be in, 6, 7 or 8?

So what gear should you be in?  How does that differ from what gear would the ZF (or PDK/ZF/DCT)etc be in, that you would criticize it for never being in the right gear?

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4 minutes ago, 52-80 said:

So what gear should you be in?  How does that differ from what gear would the ZF (or PDK/ZF/DCT)etc be in, that you would criticize it for never being in the right gear?

It depends on external factors.

 

Let me try and explain this in a different way becauseI can tell by your responses to my hypothetical situations you are looking at them statically which wasn'twhat I meant. Speed, acceleration/deceleration and throttle input are not enough information to select the proper gear. At a constant 75mph, at a given throttle, you could need to be in any of those three gears depending on what is getting ready to happen. There is no way for a slush box to know which one.

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10 minutes ago, 52-80 said:

So what gear should you be in?  How does that differ from what gear would the ZF (or PDK/ZF/DCT)etc be in, that you would criticize it for never being in the right gear?

I think his point is that an AT, of any kind, cannot anticipate a driver's intentions.  It can only assume intentions after inputs because it operates on a feedback loop.  It can get "close" to driver's intentions, and faster shifts make the transition less noticeable, but it will always "run behind."

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8 minutes ago, TwiceHorn said:

I think his point is that an AT, of any kind, cannot anticipate a driver's intentions.  It can only assume intentions after inputs because it operates on a feedback loop.  It can get "close" to driver's intentions, and faster shifts make the transition less noticeable, but it will always "run behind."

Precisely.

 

It's a flawed system, all you are doing is minimizing how flawed it is.

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5 minutes ago, G650 said:

It depends on external factors.

i was leading the convo there.  so describe the external factors, and what gear you would be in, and what you think the zf would be in?

 

5 minutes ago, G650 said:

Let me try and explain this in a different way becauseI can tell by your responses to my hypothetical situations you are looking at them statically which wasn'twhat I meant. Speed, acceleration/deceleration and throttle input are not enough information to select the proper gear. At a constant 75mph, at a given throttle, you could need to be in any of those three gears depending on what is getting ready to happen. There is no way for a slush box to know which one.

real-time speed, accel/decel, and throttle input are not JUST what modern trans like pdk and zf uses.  something that simple theyve already had in the tiptronics and slushboxes of yesterdays.  they use your selected driving mode, and a running history of driving inputs (on top of other information), to predict the gear.

 

the achievement of the prediction is to know which one most of the time.  in the edge cases that it doesnt, its statistically likely that you would not have either. 

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For daily driving where you go from aggressive to relaxed depending on the circumstances, I can see G650's point.  But, for track purposes, which is where the PDK shines. Your goal/intentions, almost always, are to have it in the right RPM/Gear for that speed.  That's where the PDK shines.  

On a track, I never touch the paddles unless I want to short shift and it is always in the proper gear.  But, unless maybe it's raining, you are always going to want to be in the power band.  It also does drop from 5th to 2nd many times seamlessly as well.  

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29 minutes ago, G650 said:

Precisely.

 

It's a flawed system, all you are doing is minimizing how flawed it is.

It's flawed from the enthusiast driver perspective.  It's a fucking miracle for the ordinary driver.

And for mileage.

For most volume passenger cars, an AT is going to be programmed for early upshifts and to hold higher gears as long as possible to eak more mileage out of the thing.  I don't think sport modes and whatnot "count" toward EPA mileage rating, just the "default" operating mode.

I'm not sure how Porsche, primarily, deals with CAFE.  Do they just blow it off and pay penalties?  I think most other makes, not including say Ferrari, make enough plain passenger vehicles driven by puds that the standard programming fits with the above. Maybe Porsche, too, with the inherent efficiency of their engines.

Edited by TwiceHorn
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21 minutes ago, Atxracer said:

For daily driving where you go from aggressive to relaxed depending on the circumstances, I can see G650's point.  But, for track purposes, which is where the PDK shines. Your goal/intentions, almost always, are to have it in the right RPM/Gear for that speed.  That's where the PDK shines.  

On a track, I never touch the paddles unless I want to short shift and it is always in the proper gear.  But, unless maybe it's raining, you are always going to want to be in the power band.  It also does drop from 5th to 2nd many times seamlessly as well.  

I'm pretty certain that a slushbox AT with a planetary gear train has to sequentially step down gears.

It looks like DCTs can skip gears, but it seems that a shift from one "odd" gear (or even) to another would require one step down, at least.  Each clutch is associated with alternating gears on a single shaft, so to go from one gear to another on the same shaft is going to require at least one "additional" shift (clutch 1 disengagement, clutch 2 engagement and back).

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15 minutes ago, TwiceHorn said:
36 minutes ago, G650 said:

 

It's flawed from the enthusiast driver perspective.  It's a fucking miracle for the ordinary driver.

No, it's actually the opposite, which is what I am trying to convey, poorly.

 

It's not just, or even mainly, performance. It's efficiency, drive train stress, brake wear and a whole host of other issues. To properly operate a vehicle you have to select gears manually.

 

By far the biggest issue is engine braking. You have to manually select gears to even come close to proper engine braking.

 

 

36 minutes ago, 52-80 said:

i was leading the convo there.  so describe the external factors, and what gear you would be in, and what you think the zf would be in?

 

real-time speed, accel/decel, and throttle input are not JUST what modern trans like pdk and zf uses.  something that simple theyve already had in the tiptronics and slushboxes of yesterdays.  they use your selected driving mode, and a running history of driving inputs (on top of other information), to predict the gear.

 

the achievement of the prediction is to know which one most of the time.  in the edge cases that it doesnt, its statistically likely that you would not have either. 

 

We are just talking at cross purposes here so I'm not sure how productive continuing is. I'm a mechanical engineer who built race cars, and have personally driven all of these examples, and own a couple of them. I know how they work. This isn't about edge cases, literally every shift an automatic makes is wrong, full stop.

I also own a fleet of commercial trucks. We run exclusively Eaton Fuller LL 8s and Mack 16 speeds for.all the reasons I'm trying to explain above.

 

27 minutes ago, Atxracer said:

For daily driving where you go from aggressive to relaxed depending on the circumstances, I can see G650's point.  But, for track purposes, which is where the PDK shines. Your goal/intentions, almost always, are to have it in the right RPM/Gear for that speed.  That's where the PDK shines.  

On a track, I never touch the paddles unless I want to short shift and it is always in the proper gear.  But, unless maybe it's raining, you are always going to want to be in the power band.  It also does drop from 5th to 2nd many times seamlessly as well.  

Absolutely, and that is what it was designed for. If you use one in a specific set of circumstances that it is intended for its better than all but the most talented drivers at making speed.

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18 minutes ago, TwiceHorn said:

I'm not sure how Porsche, primarily, deals with CAFE.  Do they just blow it off and pay penalties?  I think most other makes, not including say Ferrari, make enough plain passenger vehicles driven by puds that the standard programming fits with the above. Maybe Porsche, too, with the inherent efficiency of their engines.

Unofficially, most of Porsche's cars are geared tall because of CAFE and noise regulations. 

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3 hours ago, G650 said:

Yeah, no. Literally no box does this, not even the mythical PDK.

 

I'm always amazed at anyone who has paddles and doesn't use them. You are in the wrong gear 100% of the time if you don't.

 

3 hours ago, 52-80 said:

at max aggression ZF8HP will do a direct downshift of 3 gears rather than step down progressively.  itll automatically downshift when youre off throttle and on the brakes for a corner...but ive never driven that angrily and had it jump 3 gears while braking (only 2 at most)

 

 

It took me awhile to find an example of the PDK doing this. Go to the 1.35 mark.

 

   But yes, the PDK will jump a few gears instantly.

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4 minutes ago, G650 said:

This isn't about edge cases, literally every shift an automatic makes is wrong, full stop.
 

Empirically speaking, Atx just said it is virtually always on the right gear.  If the counter is that the exemption is on the race track, then it must always be wrong on the streets, which I dont think anything would agree with either.

 

My car has only 1 gear, so it's always in the right gear.  🤠🤠

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10 minutes ago, G650 said:

No, it's actually the opposite, which is what I am trying to convey, poorly.

 

It's not just, or even mainly, performance. It's efficiency, drive train stress, brake wear and a whole host of other issues. To properly operate a vehicle you have to select gears manually.

 

By far the biggest issue is engine braking. You have to manually select gears to even come close to proper engine braking.

 

 

 

We are just talking at cross purposes here so I'm not sure how productive continuing is. I'm a mechanical engineer who built race cars, and have personally driven all of these examples, and own a couple of them. I know how they work. This isn't about edge cases, literally every shift an automatic makes is wrong, full stop.

I also own a fleet of commercial trucks. We run exclusively Eaton Fuller LL 8s and Mack 16 speeds for.all the reasons I'm trying to explain above.

 

Absolutely, and that is what it was designed for. If you use one in a specific set of circumstances that it is intended for its better than all but the most talented drivers at making speed.

Well, I don't consider that "flawed."  It's a design limitation, for sure.  For the average, joe sixpack driver, an AT suits needs wonderfully.

And, I would submit that in steady-state operation, an AT is usually in the right gear, it's just when things go transient that it will always be behind.

 

Edited by TwiceHorn
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41 minutes ago, Atxracer said:

For daily driving where you go from aggressive to relaxed depending on the circumstances, I can see G650's point.  But, for track purposes, which is where the PDK shines. Your goal/intentions, almost always, are to have it in the right RPM/Gear for that speed.  That's where the PDK shines.  

On a track, I never touch the paddles unless I want to short shift and it is always in the proper gear.  But, unless maybe it's raining, you are always going to want to be in the power band.  It also does drop from 5th to 2nd many times seamlessly as well.  

Exactly. First time I saw that I was pretty amazed. Admittedly, as a drag racer I didn't know much about DCT's. I had to go study just to see how it was physically possible to do that. Also, the Porsche version of the PDK seems to learn a little better than others. Like I said, whoever is writing their tunes over there is pretty damned good.

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10 minutes ago, Thatguy said:

It took me awhile to find an example of the PDK doing this. Go to the 1.35 mark.

 

   But yes, the PDK will jump a few gears instantly.

yup, very good example, mine does the same thing on accel.  i meant ive never gone gung ho into a corner where the car jumped that high on auto downshift under braking.  cuz when im in driving in that mood i use manual mode (for fun, not because the auto box cant reliably predict the gear)

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2 minutes ago, Thatguy said:

Exactly. First time I saw that I was pretty amazed. Admittedly, as a drag racer I didn't know much about DCT's. I had to go study just to see how it was physically possible to do that. Also, the Porsche version of the PDK seems to learn a little better than others. Like I said, whoever is writing their tunes over there is pretty damned good.

They're a really cool design.  I think the basic idea preceded the slushbox AT, but limitations in machining gear sets and materials meant that the "torque multiplier" effect of a torque converter made slushboxes more practical.  Then, as compact multi-gear transmissions became more available, control of the clutches and shifting forks became an issue that could only be solved by eeeeelectronics.  Fuckin computers, man.

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15 minutes ago, TwiceHorn said:

Well, I don't consider that "flawed."  It's a design limitation, for sure.  For the average, joe sixpack driver, an AT suits needs wonderfully.

And, I would submit that in steady-state operation, an AT is usually in the right gear, it's just when things go transient that it will always be behind.

 

I don't think Joe Sixpack should even have a drivers license so I guess that's where we differ

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1 minute ago, G650 said:

I don't think Joe Sixpack should even have a drivers license so I guess that's where we differ

There is that.  I'm just particularly fascinated by "mechanical, analog" controlled systems like pre-electronics carburetors and automatic transmissions.  They are ungodly innovative and ingenious.

Electronic controls open up a whole new world that's pretty cool, but  . . . . 

Edited by TwiceHorn
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I'm always amazed at anyone who has paddles and doesn't use them. You are in the wrong gear 100% of the time if you don't.


Because even in the wrong gear, the car has enough power to do what i want it to do. I don't care that it takes a half second longer. I'm not in a race.
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4 hours ago, Thatguy said:

Exactly. First time I saw that I was pretty amazed. Admittedly, as a drag racer I didn't know much about DCT's. I had to go study just to see how it was physically possible to do that. Also, the Porsche version of the PDK seems to learn a little better than others. Like I said, whoever is writing their tunes over there is pretty damned good.

I'd bet even moreso than tunes, the mechanical design of the PDK is more "critical" than other DCTs.  The clutch plates are closer together and probably sprung more heavily, the solenoids probably more powerful, shorter throws on the gear forks, etc.  All of which makes it potentially more unreliable if the manufacturing isn't "just so," which it probably is as that's Porsche's signature.

I do see that the ZF8 apparently can jump more than one gear, but I'm thinking that it's between two particular gears, or a limited set of pairs of gears, due to the nature of planetary gear sets.

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3 hours ago, TwiceHorn said:

I do see that the ZF8 apparently can jump more than one gear, but I'm thinking that it's between two particular gears, or a limited set of pairs of gears, due to the nature of planetary gear sets.

Yeah I can't remember off the top of my head which ones, but it's certain pairs.

 

The ZF8 is probably the world's best all around transmission in my estimation. DCTs are not very good for street cars as when you try to make out shift speed you have to trade off jerky low speed operation. The ZF shift times have gotten within milliseconds of the DCT, practically unnoticeable to most drivers, and still performs well at low speed.

 

I've got a 9 speed Merc in my DBX. It's an interesting unit. They down shifts are super aggressive which I like, but 4 to 3 is a strange jump for whatever reason.

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evija is going to eat your children:

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Formula 1 cars aside, no Lotus has ever accelerated so quickly. The Evija's straight-line performance is outside normal frames of reference, both in terms of its instantaneous savagery and the lack of drama that accompanies it. This is, for want of a better term, a quietly startling vehicle to drive. The objective evidence of g-forces and spiraling numbers on the car's digital display is in total contrast to the lack of anything like a recognizable supercar soundtrack, with nothing more than a muscular electrical hum entering the cockpit. We reached the 140-mph speed limiter well before the end of one of Hethel's longer straights, the rapidly approaching braking zones coming as a surprise every time. Lotus figures the production Evija will be able to bolt from rest to 186 mph in an astonishing nine seconds or so. For comparison, the quickest car we've ever tested, the Bugatti Chiron Sport, needed 12.4 seconds to hit 180 mph.

2021-lotus-evija-prototype-117-161953671

 

2021-lotus-evija-prototype-132-161953672

 

2021-lotus-evija-prototype-114-161953671

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Mu buddy who is GM of the local Porsche/Audi/Jag dealer says he is steady buying back all brands for more than he sold them for.

 

The AM dealer in DC offered me almost the same price I paid for my X5M 140k miles ago.

 

It's bonkers.

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