Base GT-R lobs 7:38 Nordschleife Supertest Lap Time
#136
You are wrong on so many levels. Number 1 is that you posted telemetry from the 7:38 lap, which is who knows how much slower on that back straight.
Number 2 is that the very same telemetry shows a plateau in the acceleration curve, albeit brief. Granted he didn't lose speed like Harris did so I'll give you a pardon on that one.
And finally, the GT2 still, with a much more significant lift puts almost 2 seconds on the GT-R on that back straight (from the sign, not from Galgenkopf), yet a ZR-1, Zonda, CGT, CCX, Enzo and ACR, of all of them, driven fast by whomever, could not put 2 seconds on the GT-R????? You can't cry headwind for everybody! Not to mention the GT2 had 13 mph on the GT-R prior to any lifts. And Harris gained something like 3-4 seconds from the Exit of Galkenkopf to the end of the lap.
Number 2 is that the very same telemetry shows a plateau in the acceleration curve, albeit brief. Granted he didn't lose speed like Harris did so I'll give you a pardon on that one.
And finally, the GT2 still, with a much more significant lift puts almost 2 seconds on the GT-R on that back straight (from the sign, not from Galgenkopf), yet a ZR-1, Zonda, CGT, CCX, Enzo and ACR, of all of them, driven fast by whomever, could not put 2 seconds on the GT-R????? You can't cry headwind for everybody! Not to mention the GT2 had 13 mph on the GT-R prior to any lifts. And Harris gained something like 3-4 seconds from the Exit of Galkenkopf to the end of the lap.
See link, Bottom right, Note TPOS, The red is the 7:29 lap and the blue is the 7:38.
The GT-R's speed actually plateaus before reaching the kink at Hohe because the initial half of the straight is uphill. Then it accelerates again, gaining 10 to 12 km/h as the track levels out and then falls steeply into Tiergrten, before finally braking for the high speed left-right.
Both the downhill Tiergarten sector and using WOT through the kink are critical to achieving these high top speeds in the GT-R. Otherwise it's just not going to happen.
The 7:38 car maxed out at 284km/h at Tiergarten, before the braking point and the 7:29 car hit 290km/h at the same point. This means the S1 car would have plateaud at 272 to 274km/h at Dottinger Hohe which is exactly the same speed that DR recorded at Dottinger Hohe in the S1 JDM GT-R they used
Knowing that Magnussen maxed 295km/h on the Nurburgring straight in the C6 Z06, there really are no more questions to be asked about the GT-R. No ringer theory can be supported unless severe delusion has taken hold.
Last edited by gp900bj; 06-16-2009 at 08:57 PM.
#137
Note that between the red and yellow point, the GT2 has to wipe off more speed.
#138
You're ignoring the fact that Harris had to short shift the GT2 all over the track for fear of losing traction. An oily track with well worn Michelin's was more of a disadvantage for the GT2 than the GT-R. And it's odd that Chris Harris makes no mention of these multiple damp sections holding back the GT-R as you insinuate.
Drivers Republic 017:
"But you already know that the GT-R can do astonishing things with asphalt, that it conjures far more forward momentum than its 272bhp-per-tonne would suggest is possible and it changes direction so obediently you wonder if the quoted 1740kg kerb weight is a typographical blunder. It is one of only two cars I have driven that actively imposes its demands on the road surface and then actuates its mechanicals accordingly."
Drivers Republic 030:
"In the wet and the damp, and on a cold surface that denies it the tyre temperature it so needs to operate to its proper abilities, the GT-R feels every bit as big as its 1740kg weight suggests. Like the GT2, either axle will relinquish grip at any time, but the lack of traction is the most surprising problem. The main issue here is that to anyone who has experienced its extraterrestrial abilities, the GT-R is loaded with expectation - you expect it to fashion something from nothing - but a wet Nurburgring vanquishes its indomitability. It's still far more driveable than something so heavy has any right to be, but on the treacherous sections that had the GT2 instantaneously slithering a car width to the outside of the turn, a the GT-R's greater mass forces it even further to the outside of the circuit."
Now, consider these other quotes by DR test editors:
"We were genuinely impressed (more so than we had anticipated) at the GT2’s sheer speed but also how much traction it found in conditions which would have (in theory) suited the GT-R better.
As we assembled this feature and concluded on the times there were several aspects that struck us; firstly the GT2 found much more traction that we would expect on its cup+ tyres and therefore there was little or no traction advantage conferred by the GT-R's 4wd."
--Steve Davies
"I think the Cup+ proved itself in the damp conditions - some time before the laps were timed. And the tread pattern is much more pronounced than the normal Cup tires - and I'd expect as Meyrick said, the compound is different, too."
--Jethro Bovingdon
"Uphill kink (no name): damp bits...the kink was even slower than usual and very slippery. Lost heaps of time here from the official GT-R lap.
This righthander, Hatzenbach, what you can't see here, the apex is very slippery and both cars lose time there, straight away."
To conclude that the conditions didn't hold the GT-R back anywhere is absurd. Obviously it did.
And it sounds like you who are "spinning" things, because you said earlier the track was dry, when the commentary in the article (printed in both DR and Automobile Magazine) and the commentary in the video shows the track was anything but ideal, with numerous references to damp, oil, and a slippery track. How do you know he could absolutely 100% not knock off even more time than he thinks he could, with more familiarization, a bone dry track, and VDC turned fully off? You don't.
#139
[...]
Drivers Republic 030:
"In the wet and the damp, and on a cold surface that denies it the tyre temperature it so needs to operate to its proper abilities, the GT-R feels every bit as big as its 1740kg weight suggests. Like the GT2, either axle will relinquish grip at any time, but the lack of traction is the most surprising problem. The main issue here is that to anyone who has experienced its extraterrestrial abilities, the GT-R is loaded with expectation - you expect it to fashion something from nothing - but a wet Nurburgring vanquishes its indomitability. It's still far more driveable than something so heavy has any right to be, but on the treacherous sections that had the GT2 instantaneously slithering a car width to the outside of the turn, a the GT-R's greater mass forces it even further to the outside of the circuit."
Now, consider these other quotes by DR test editors:
"We were genuinely impressed (more so than we had anticipated) at the GT2’s sheer speed but also how much traction it found in conditions which would have (in theory) suited the GT-R better.
As we assembled this feature and concluded on the times there were several aspects that struck us; firstly the GT2 found much more traction that we would expect on its cup+ tyres and therefore there was little or no traction advantage conferred by the GT-R's 4wd."
--Steve Davies
"I think the Cup+ proved itself in the damp conditions - some time before the laps were timed. And the tread pattern is much more pronounced than the normal Cup tires - and I'd expect as Meyrick said, the compound is different, too."
--Jethro Bovingdon
"We were genuinely impressed (more so than we had anticipated) at the GT2’s sheer speed but also how much traction it found in conditions which would have (in theory) suited the GT-R better.
As we assembled this feature and concluded on the times there were several aspects that struck us; firstly the GT2 found much more traction that we would expect on its cup+ tyres and therefore there was little or no traction advantage conferred by the GT-R's 4wd."
--Steve Davies
"I think the Cup+ proved itself in the damp conditions - some time before the laps were timed. And the tread pattern is much more pronounced than the normal Cup tires - and I'd expect as Meyrick said, the compound is different, too."
--Jethro Bovingdon
What about these?:
"Uphill kink (no name): damp bits...the kink was even slower than usual and very slippery. Lost heaps of time here from the official GT-R lap.
This righthander, Hatzenbach, what you can't see here, the apex is very slippery and both cars lose time there, straight away."
To conclude that the conditions didn't hold the GT-R back anywhere is absurd. Obviously it did.
"Uphill kink (no name): damp bits...the kink was even slower than usual and very slippery. Lost heaps of time here from the official GT-R lap.
This righthander, Hatzenbach, what you can't see here, the apex is very slippery and both cars lose time there, straight away."
To conclude that the conditions didn't hold the GT-R back anywhere is absurd. Obviously it did.
yet Suzuki was able to go 12 seconds faster. A year later, and with some very minor modifications (nothing that would affect hp/wt in any meaningful way), lo and behold, he too is 12 seconds faster.
And it sounds like you who are "spinning" things, because you said earlier the track was dry, when the commentary in the article (printed in both DR and Automobile Magazine) and the commentary in the video shows the track was anything but ideal, with numerous references to damp, oil, and a slippery track. How do you know he could absolutely 100% not knock off even more time than he thinks he could, with more familiarization, a bone dry track, and VDC turned fully off? You don't.
And it sounds like you who are "spinning" things, because you said earlier the track was dry, when the commentary in the article (printed in both DR and Automobile Magazine) and the commentary in the video shows the track was anything but ideal, with numerous references to damp, oil, and a slippery track. How do you know he could absolutely 100% not knock off even more time than he thinks he could, with more familiarization, a bone dry track, and VDC turned fully off? You don't.
#140
Hey - if there is real telemetry data available, why not simply calculate the horsepower at the wheels? Take the time differential of speed, low-pass filter, smooth (running average), multiply by mass, use engine speed to convert to HP, and plot against engine speed.
Overlay the result against published hp curves, and see if the car was a 'ringer' or not? Based on the snippets of engine speed as a function of time, the sample rate appears high enough for useful numbers, and the calculation can be performed with only the RPMs if needed by backing out velocity through known gearing, etc.
This isn't that hard -- Am I missing something?
Or is the ongoing debate too much fun to risk ending?
Overlay the result against published hp curves, and see if the car was a 'ringer' or not? Based on the snippets of engine speed as a function of time, the sample rate appears high enough for useful numbers, and the calculation can be performed with only the RPMs if needed by backing out velocity through known gearing, etc.
This isn't that hard -- Am I missing something?
Or is the ongoing debate too much fun to risk ending?
#141
Doesn't matter that the track had dried considerably. There were enough references to damp/oily/slippery to conclude that the GT-R was obviously hampered by conditions.
This was written after the timed laps (and thus, after the really wet part):
"This was never going to be an exact exercise. The track wasn't completely dry, the ambient temperature was 7C."
Harris does repeat his comment about the GT-R pushing wide where the GT2 didn't, during the timed lap. It comes in the right-hander after the section with Metzgesfeld.
"And it's odd that Chris Harris makes no mention of these multiple damp sections holding back the GT-R as you insinuate."
The fact remains that the actual driver in question, a guy who has race experience at the ring, felt he extracted more out of the GT-R than the GT2. We have his statement on the matter versus your conjecture from the bleacher section. Hmm, which is more convincing? Furthermore, I provided you with multiple narrations from Harris on the multiple points during his timed laps where he felt the GT-R handled damp sections better. You conveniently ignored these. Lastly, I never said the track was bone dry or ideal in any way. I was referring to ANOTHER statement made by Harris that when the track had dried, the advantage swung back in favor of the GT-R with its Bridgestones.
I didn't ignore them. You made valid comments. But so are my comments that the GT-R was held back by the conditions, and arguing about which was held back more is pretty ridiculous. The dry-weather result with this driver with both cars on the same day hasn't happened so it's all conjecture. Got it?
Your statement from Harris about the GT-R and the dry:
"...it will surely be possible to extract a greater percentage of the GT-R's performance potential"
Future tense. He is conjecturing about something, so long as something else happens (dry track, with good grip). As it turned out, there were still plenty of damp/oily/slippery sections, many of which proved to be the GT-R's undoing because of its mass (which wouldn't be a problem in dry).
#142
7:29 lap is in red. 7:38 is in blue. As you can see, there's not much between them on the back straight.
Pardon? There's nothing to pardon. I stated something as fact, and it has finally taken you this long to acknowledge it. Actually, you should probably apologize for your "Go ahead put your foot in your mouth for me" statement. As it was not I who had a foot in his mouth.
There is not really a plateau. The speed continues to rise, only very, very slowly. Unlike the ZR1 which briefly hit 176 just before the hill, then slowed to 173 and then wavered at ~174 for ages.
The Zonda was misfiring near the end of the lap. Enzo had failed dampers, so could have been hampered by the Galgenkopf exit speed. ACR, well, the fact that you are bringing that one up shows how desperate you are. The ACR tops out at around 175 mph, and probably has pretty bad total drag force due to its frontal area and the aero pieces. In a test by Automobile Magazine, it took 24.9 seconds to go from 150 to 170. The GT2 in the same test took only 7.6 seconds. It took the ACR more time to go from 150-170 than it took the GT2 to do 150-190+.
And actually, the wind is not a minor consideration. If you watch the videos at supercarmovies.com, you'll see there's a pretty strong wind on many shots of these cars as they come down the straight.
I'm still waiting for the press release by Nissan saying they hit 290 kph twice. I could have missed it though.
Pardon? There's nothing to pardon. I stated something as fact, and it has finally taken you this long to acknowledge it. Actually, you should probably apologize for your "Go ahead put your foot in your mouth for me" statement. As it was not I who had a foot in his mouth.
There is not really a plateau. The speed continues to rise, only very, very slowly. Unlike the ZR1 which briefly hit 176 just before the hill, then slowed to 173 and then wavered at ~174 for ages.
The Zonda was misfiring near the end of the lap. Enzo had failed dampers, so could have been hampered by the Galgenkopf exit speed. ACR, well, the fact that you are bringing that one up shows how desperate you are. The ACR tops out at around 175 mph, and probably has pretty bad total drag force due to its frontal area and the aero pieces. In a test by Automobile Magazine, it took 24.9 seconds to go from 150 to 170. The GT2 in the same test took only 7.6 seconds. It took the ACR more time to go from 150-170 than it took the GT2 to do 150-190+.
And actually, the wind is not a minor consideration. If you watch the videos at supercarmovies.com, you'll see there's a pretty strong wind on many shots of these cars as they come down the straight.
I'm still waiting for the press release by Nissan saying they hit 290 kph twice. I could have missed it though.
Automotive knowledge 101, you can have misfires and it not kill your speed.
And that GT-R was about .7 slower from the one sign to the next (~23.2). This leaves all exit speed concerns out of the question. because obviously all of these cars are as fast or faster in the turn than the GT-R. The ZR-1 is already at 140 mph at the sign, something I doubt the GT-R would have been doing at that point. I don't think anyone here would consider the GT-R strong above 100 and strong at all over 130.
You can bag on the ACR all you want, but even bouncing off the rev limiter it hit that straight in 23 seconds, though it's exit speed was likely much higher than anyone else. You do realize the aero is adjustable and that top speed runs can vary on that car too right? And that they had engineers there who KNEW there was a long back straight too right?
#143
So now you're saying the GT2, on worn Cups, was better in the wet than the GT-R, even with its AWD. Ok...
Doesn't matter that the track had dried considerably. There were enough references to damp/oily/slippery to conclude that the GT-R was obviously hampered by conditions.
This was written after the timed laps (and thus, after the really wet part):
"This was never going to be an exact exercise. The track wasn't completely dry, the ambient temperature was 7C."
Harris does repeat his comment about the GT-R pushing wide where the GT2 didn't, during the timed lap. It comes in the right-hander after the section with Metzgesfeld.
There were damp conditions all around the track during the timed run.
Actually, you did:
"And it's odd that Chris Harris makes no mention of these multiple damp sections holding back the GT-R as you insinuate."
Suspension "tweaks"? I thought it was all about hp/wt. Suddenly, these little tweaks matter when explaining how HvS couldn't get a "ringer" GT-R around the 'Ring in under 7:50.
I'll repeat (because it seems that you have not taken the time to consider this): Harris drove with the VDC still on. Parts of the track were still damp, oily, and downright slippery. What the hell else is he going to do when the GT-R starts understeering and the power cuts off?? Drive like a madman like Suzuki (in the dry) with a personal customer car generously lent to them by a friend? That's the limit of the GT-R, in those conditions, with those settings. That's not to say the limits are the same in the dry. As Suzuki shows (and Millen and 'Ring driving instructor Dale Lomas will tell you), the GT-R has a different driving style in the dry that would likely be suicidal in damp/oily conditions.
I didn't ignore them. You made valid comments. But so are my comments that the GT-R was held back by the conditions, and arguing about which was held back more is pretty ridiculous. The dry-weather result with this driver with both cars on the same day hasn't happened so it's all conjecture. Got it?
Your statement from Harris about the GT-R and the dry:
"...it will surely be possible to extract a greater percentage of the GT-R's performance potential"
Future tense. He is conjecturing about something, so long as something else happens (dry track, with good grip). As it turned out, there were still plenty of damp/oily/slippery sections, many of which proved to be the GT-R's undoing because of its mass (which wouldn't be a problem in dry).
Doesn't matter that the track had dried considerably. There were enough references to damp/oily/slippery to conclude that the GT-R was obviously hampered by conditions.
This was written after the timed laps (and thus, after the really wet part):
"This was never going to be an exact exercise. The track wasn't completely dry, the ambient temperature was 7C."
Harris does repeat his comment about the GT-R pushing wide where the GT2 didn't, during the timed lap. It comes in the right-hander after the section with Metzgesfeld.
There were damp conditions all around the track during the timed run.
Actually, you did:
"And it's odd that Chris Harris makes no mention of these multiple damp sections holding back the GT-R as you insinuate."
Suspension "tweaks"? I thought it was all about hp/wt. Suddenly, these little tweaks matter when explaining how HvS couldn't get a "ringer" GT-R around the 'Ring in under 7:50.
I'll repeat (because it seems that you have not taken the time to consider this): Harris drove with the VDC still on. Parts of the track were still damp, oily, and downright slippery. What the hell else is he going to do when the GT-R starts understeering and the power cuts off?? Drive like a madman like Suzuki (in the dry) with a personal customer car generously lent to them by a friend? That's the limit of the GT-R, in those conditions, with those settings. That's not to say the limits are the same in the dry. As Suzuki shows (and Millen and 'Ring driving instructor Dale Lomas will tell you), the GT-R has a different driving style in the dry that would likely be suicidal in damp/oily conditions.
I didn't ignore them. You made valid comments. But so are my comments that the GT-R was held back by the conditions, and arguing about which was held back more is pretty ridiculous. The dry-weather result with this driver with both cars on the same day hasn't happened so it's all conjecture. Got it?
Your statement from Harris about the GT-R and the dry:
"...it will surely be possible to extract a greater percentage of the GT-R's performance potential"
Future tense. He is conjecturing about something, so long as something else happens (dry track, with good grip). As it turned out, there were still plenty of damp/oily/slippery sections, many of which proved to be the GT-R's undoing because of its mass (which wouldn't be a problem in dry).
#144
Unfortunately, the telemetry data released by Nissan (as you can see in gp's post) doesn't include rpm's. However, there is a simpler way (using any simple graphics program like MS Paint) to estimate the speed of the GT-R based on the values shown (velocity in the y-axis) and cross-referencing the car's location relative to time (x-axis) in the video. Which is how I arrived at the GT-R's first "290 kph" moment at Schwedenkreuz, and its location on track where the true 290 kph speed was reached; it agreed with the video both times, to within a few 1/10ths of a second
The resulting point cloud will either be completely contained within the published/measured curves, or some points will exceed (eg. ringer)...
Still say it's do-able
#145
CHILL with the misfiring crap, you can look for yourself, there are not one but two videos of the Zonda on the ring running sub 7:30, one if a 7:24 and the other is a 7:27, and they both ran near the same split from the first sign on dottinger to the dottinger curve (22.5 - 22.6) . There was nothing holding that Zonda back.
"Immediately after setting that record time – 7min 27.82sec – he and the F were on a lap believed to be some four to six seconds faster, but a fuel starvation problem forced it to be abandoned."
I already know there are not one but two videos of the Zonda on the 'Ring. Both times, they had problems related to fueling. Of course your times might be similar. Neither were running at optimum. So what's your point? To compare one underperforming Zonda against...another underperforming Zonda?
The misfires were apparently important enough for them to mention them.
And that GT-R was about .7 slower from the one sign to the next (~23.2). This leaves all exit speed concerns out of the question. because obviously all of these cars are as fast or faster in the turn than the GT-R. The ZR-1 is already at 140 mph at the sign, something I doubt the GT-R would have been doing at that point. I don't think anyone here would consider the GT-R strong above 100 and strong at all over 130.
You don't know that all of these cars were faster in the turn than the GT-R. The GT-R (on Bridgestones) was faster in some corners than the ACR in C&D's test at Buttonwillow, remember? It is apparently outcornering the ZR1 in the latest Auto Bild test, because it sure was slower in a straight line.
However, leaving out the exit speeds could be a huge part of your problem. Check out the GT-R's exit speeds in this Car Magazine comparo with the Turbo:
Notice that it pulls close to the Turbo, and in some straights continues to pull harder because it doesn't lose speed with the shifts. And this was a customer GT-R, delivered to the owner only a day before the test.
There is a similar result in Sport Auto's fahrberichte of the GT-R compared to the 997TT on the Nurburgring GP course.
You can bag on the ACR all you want, but even bouncing off the rev limiter it hit that straight in 23 seconds, though it's exit speed was likely much higher than anyone else. You do realize the aero is adjustable and that top speed runs can vary on that car too right? And that they had engineers there who KNEW there was a long back straight too right?
Bouncing off the rev limiter...thanks for giving yet another explanation as to why the ACR wasn't as fast as it was. Based on the elevation, the ACR could be down almost 40 hp from its SAE net rating too.
Look at the R&T result with the ACR & GT-R on the speedway. The GT-R was faster than the ACR. And unlike the ACR, this GT-R did not have an engineer on hand to maximize the GT-R's performance here. Yet it still hit a higher maximum speed, as well as a higher avg.
http://www.roadandtrack.com/assets/d...8_cvr_oval.pdf
#146
These are the manufacturer recorded 'ring top speeds for several cars.
C6 Z06 - Magnussen - 295km/h
ZR1 - Mero - 290km/h
997 GT2 - Rohrl - 304km/h
R35 GT-R - Suzuki - 290km/h
CTS-V - Hienricy - 282km/h
Of all these cars the ZR1 is clearly the anomaly.
The GT-R's top speed actually makes perfect sense.
C6 Z06 - Magnussen - 295km/h
ZR1 - Mero - 290km/h
997 GT2 - Rohrl - 304km/h
R35 GT-R - Suzuki - 290km/h
CTS-V - Hienricy - 282km/h
Of all these cars the ZR1 is clearly the anomaly.
The GT-R's top speed actually makes perfect sense.
#147
These are the manufacturer recorded 'ring top speeds for several cars.
C6 Z06 - Magnussen - 295km/h
ZR1 - Mero - 290km/h
997 GT2 - Rohrl - 304km/h
R35 GT-R - Suzuki - 290km/h
CTS-V - Hienricy - 282km/h
Of all these cars the ZR1 is clearly the anomaly.
The GT-R's top speed actually makes perfect sense.
C6 Z06 - Magnussen - 295km/h
ZR1 - Mero - 290km/h
997 GT2 - Rohrl - 304km/h
R35 GT-R - Suzuki - 290km/h
CTS-V - Hienricy - 282km/h
Of all these cars the ZR1 is clearly the anomaly.
The GT-R's top speed actually makes perfect sense.
http://www.rennteam.com/forum/thread...GT2/index.html
I wonder if those numbers are enough to convince the doubters that the ZR1 really was vastly underperforming on the straight. Apparently, the word from GM's engineers themselves isn't enough.
#148
Rohrl says the GT2 hit 310 going into Tiergarten:
http://www.rennteam.com/forum/thread...GT2/index.html
I wonder if those numbers are enough to convince the doubters that the ZR1 really was vastly underperforming on the straight. Apparently, the word from GM's engineers themselves isn't enough.
http://www.rennteam.com/forum/thread...GT2/index.html
I wonder if those numbers are enough to convince the doubters that the ZR1 really was vastly underperforming on the straight. Apparently, the word from GM's engineers themselves isn't enough.
So there you go. The GT-R was 20km/h slower than the GT2 at the Tiergarten.
Yeah, the ringer theory is dying a slow painful death.
#149
Oh no it hasn't! Suzuki San knew that the top speed of the GT2 would've been used to compare with the top speed of his 'ringer' GTR, so at that point, he deliberately backed off the accelerator a little so that the GTR did not go above 290km/h
Those sly Japanese at Nissan has it all worked out and is always a step ahead of us!
If i can have a penny for every time HC or Monaro gets proven wrong - i would be a rich man by now. Hahaha
Those sly Japanese at Nissan has it all worked out and is always a step ahead of us!
If i can have a penny for every time HC or Monaro gets proven wrong - i would be a rich man by now. Hahaha
#150
Thanks for that link. I've been looking for that info for a while now. The 304km/h was during a secondary comparo where they pitted Rohrl in the GT2 against a German rider on a CBR at the 'ring. And he did state that the GT2 went quicker during his timed run.
So there you go. The GT-R was 20km/h slower than the GT2 at the Tiergarten.
Yeah, the ringer theory is dying a slow painful death.
So there you go. The GT-R was 20km/h slower than the GT2 at the Tiergarten.
Yeah, the ringer theory is dying a slow painful death.
Re: ACR
It looks like we can indeed again cite "strong headwind" as a reason for why it did not perform the way it should, relative to the GT-R.
So, in 2 out of 2 tests of the top American cars at the 'Ring, both times they faced a heavy headwind. Watching the various supercars passing on the straight on supercarmovies.com, we can see the trees whipped by wind. Obviously, with the hundreds (or thousands) of laps that Nissan has done, they were more likely to encounter "perfect conditions" (zero wind, or even a tailwind). This is not cheating.
Can't be sure, but it looks like the ACR was only doing about 257 km/h into Tiergarten?