GT-R breaks its own Ring record

[footie]

Originally Posted by rapistwit

This all seems like excuse making. Porsche flat out says the 997 Turbo ran a 7:38 while testing the GTR that they could only manage a 7:54.
Funny how every single unbiased head to head I've seen shows the GTR beating the Turbo. Why aren't you calling Porsche out on this?

I also find it amazing that some many believe Porsche yet Driver Republic's Chris Harris couldn't approach the GT2 time Porsche achieved but did match their GTR time. Does this mean that Chris was rating his own abilities too highly, thinking that Suzuki would only shave a possible 10 second off his time.

The ring is the ultimate track but it's also a very tricky track to get right, with over seventy corners and bumpier than no other track I know of it takes incredible skill and knowledge to get right. I keep repeating myself with very few listening, SportAuto drivers know the track extremely well but only get 3 laps to produce that perfect lap in one of their supertests, so car knowledge will improve lap times and weather conditions will make a huge difference.

If Horst gets another go in the GTR and gets a lot of things right on that day then I believe he will get a lap time of 7:40 or even less, he reckons that's possible so why doubt him. My point is how much extra knowledge of the car and countless laps with the added will/need to be the quickest without fail could cause that time to drop?

Nissan aren't cheating, of this I am sure.

[rapistwit]

Originally Posted by swamp2

Isn't this just also mental mastrubation as well? Cars are different and certainly perform differently on different tracks. Some tracks favor weight and handling whereas other favor hp and aerodynamics. Many of the other tracks where the cars have been compared are much slower speed tracks. Now all that being said the evidence based on such Porsche-Nissan comparisons do support the possibility of the Nissan times but only with the approximate 530 hp in the GT-R.

One of my favorite quotes (from Carl Sagan) is "Extraordinary claims require extraordinary evidence". That is all that is happening here IMHO.

I think you are missing for forrest for the trees if you only need one piece of evidence to justify such an extraordinary claim.

First off, I'm not necessarily saying the time was legit.
Secondly, I'm not basing my opinion on one piece of evidence.
Thirdly, I own one and know how wickedly fast it is.

What I'm saying is that the GT-R has been shown to beat the 997 Turbo and GT3 consistently by unbiased reviewers. And if (a big if) you believe Porsche's claim of a 7:38 in the Turbo then a sub 7:30 in the GTR seems plausible.

Dissecting entering and exiting speeds and trying to coorelate power, AWD, aerodynamics, tire selection, driver experience, and weight seems like an excercise that will collapse on itself because of too many variables.
IMO, the only way you can judge these cars is relative performance.

[jaeS4]

Another Off topic since we're also talking about under-rating , Edmunds just put the 750 on the dyno and got 391 wheel hp. BMW rates the 750i at 407hp, and Edmunds estimates are probably around 450hp.

http://www.motorauthority.com/2009-b...den-power.html

[footie]

I wonder where the 180mph peak speed of the GTR came from because I have re-checked the matched up video of the ZR1 vs GTR (7:29lap) and the ZR1 didn't even reach 180mph, it actually only reach 174mph just before the bridge and in fact reached a peak speed of 178mph on the downward stretch just after the bridge, while all the time it was continuously pulling away from the GTR.

I can't say for sure what speed the GTR did but I can say for definite that it wasn't doing 180mph. So maybe all of that number crunching you did swamp looks to have been a total waste of time.

So where exactly did Chris reach his 168.2mph and based on the above do you not think it's about time to rethink the actual peak speed Suzuki's GTR reached as well. Maybe we are talking about a figure of only a few mph apart and not the 12mph originally suggested.

P.S.

BTW here is the peak speeds of all the cars tested on that two day test from EVO magazine

Pagani Zonda F (640hp) speed 181.6mph
Porsche Carrera GT (604hp) speed 183.5mph
Maserati (621hp) speed 183.5mph
Ferrari Enzo (650hp) speed 189.2mph
Koenigsegg CCX (901hp) speed 190mph

ZR1 (635hp) speed 178mph
Suzuki's GTR (?hp) speed 173mph (possibly by my thinking)
DR's GTR (480hp*) speed 168.2mph *= quoted output

[swamp2]

Originally Posted by footie

If Horst gets another go in the GTR and gets a lot of things right on that day then I believe he will get a lap time of 7:40 or even less, he reckons that's possible so why doubt him. My point is how much extra knowledge of the car and countless laps with the added will/need to be the quickest without fail could cause that time to drop?

The words either direct quote or paraphrase from Horst were that a time less than 7:40 is pretty much optimistic, 7:50 shows the true potential of the car. I don't doubt Horst can achieve 7:4X but definitely won't get a 7:3X, again assuming about 530 hp.

Originally Posted by footie

Nissan aren't cheating, of this I am sure.

Again everytime you say such nonsense I will bring up the fact that 530 hp is not equal to 480 hp and that two wrongs don't make a right. Nissan are cheating.

[footie]

Originally Posted by swamp2

The words either direct quote or paraphrase from Horst were that a time less than 7:40 is pretty much optimistic, 7:50 shows the true potential of the car. I don't doubt Horst can achieve 7:4X but definitely won't get a 7:3X, again assuming about 530 hp.

Why not wait for a true test in a Euro spec GTR and see what he is capable of achieving, with hopefully favourable track and weather conditions.

Originally Posted by swamp2

Again everytime you say such nonsense I will bring up the fact that 530 hp is not equal to 480 hp and that two wrongs don't make a right. Nissan are cheating.

I will repeat again, as everyone is doing it then for Nissan to take the moral high ground would leave them at a major disadvantage. As we now have two confirmed cases of BMW cheating on hp figures do you not think using this defence is nul and void.

[swamp2]

Originally Posted by rapistwit

First off, I'm not necessarily saying the time was legit.
Secondly, I'm not basing my opinion on one piece of evidence.
Thirdly, I own one and know how wickedly fast it is.

Hey congrats on a wonderful car. I keep having to remind folks how much I admire and respect the GT-R. A true supercar beater for an amazing price.

Originally Posted by rapistwit

What I'm saying is that the GT-R has been shown to beat the 997 Turbo and GT3 consistently by unbiased reviewers. And if (a big if) you believe Porsche's claim of a 7:38 in the Turbo then a sub 7:30 in the GTR seems plausible.

Dissecting entering and exiting speeds and trying to coorelate power, AWD, aerodynamics, tire selection, driver experience, and weight seems like an excercise that will collapse on itself because of too many variables.
IMO, the only way you can judge these cars is relative performance.

Sorry frankly this is spoken very much from the laymans perspective. Your argument of relative track performance actually has more variables and uncertainty than such an analysis on a straight section. That should be obvious. Also the idea with much of my work is not to simply rank the cars but to quantify various parts of the arguments.The idea is to isolate effects and remove uncertainty and that is what a straight section does. Did you bother reading my just prior post on this topic in reply to footie (#221)? I suppose you might also argue that 1/4 mi trap speed is not very strongly related to power and weight? Good luck with that argument.

[swamp2]

Originally Posted by footie

Why not wait for a true test in a Euro spec GTR and see what he is capable of achieving, with hopefully favourable track and weather conditions.

Sure we are all waiting but nothing like making the correct prediction for the right reasons in advance.

Originally Posted by footie

I will repeat again, as everyone is doing it then for Nissan to take the moral high ground would leave them at a major disadvantage. As we now have two confirmed cases of BMW cheating on hp figures do you not think using this defence is nul and void.

Give me a break, "everyone". Hardly. Certainly none of those who have agreed to SAE power certification are cheating. I would hardly say the BMW cases are "confirmed". Without a crank engine dyno on a very expensive dyno you never really get "confirmation" you get suspicion based on all the same stuff we go over and over; drag times, lap times, rough dyno figures with estimated drive train losses and simulation.

Any way you want to slice it Nissan is not alone and all under rating IS LYING AND CHEATING.

Were you waiting to get back to me to discuss what "other" effects will govern straight line vehicle performance?

[Garissimo]

Originally Posted by footie

[...]
I can't say for sure what speed the GTR did but I can say for definite that it wasn't doing 180mph.

Then you'll need to reconcile what ever you're basing that assertion on with the telemetry data below.

Originally Posted by footie

So maybe all of that number crunching you did swamp looks to have been a total waste of time.

Here's the telemetry from the 7:29 run (area of interest added by me). Note that the velocity graph is scaled to the min/max of the observed data set. The max is 290 kph. This is about as straight forward as it gets. If you're willing to believe Nissan's 7:29 claim, it should follow that you accept their very own telemetry data, correct?

[bruce.augenstein@comcast.]

Originally Posted by swamp2

...Were you waiting to get back to me to discuss what "other" effects will govern straight line vehicle performance?

Tire slip.

I know this to be true from experience (drag racing and on-board G meter), but a quarter mile simulation with my loss-leader software confirms a traction-limited car can have a loss of up to several mph in trap speed without major wheel spin (except in the first 60 feet or so).

I've experienced this in stock or nearly stock street Vettes where they'd lose close to 10% of the expected G values in cold weather at around 80 mph or so. Reason: Poor traction from summer sneakers. Likewise, cold (meaning early morning) conditions at a drag strip can subtract from trap speeds, even when starting off in second gear to guarantee initial traction - which by the way tends to raise trap speeds as compared to first-gear launches.

Since the DR test was done on a damp track, this could be a major factor at 100 mph all the way to top speed with cars of this nature. Figure two to three percent slip when optimal, and several times that amount when it's damp.

[rapistwit]

Originally Posted by swamp2

Hey congrats on a wonderful car. I keep having to remind folks how much I admire and respect the GT-R. A true supercar beater for an amazing price.



Sorry frankly this is spoken very much from the laymans perspective. Your argument of relative track performance actually has more variables and uncertainty than such an analysis on a straight section. That should be obvious. Also the idea with much of my work is not to simply rank the cars but to quantify various parts of the arguments.The idea is to isolate effects and remove uncertainty and that is what a straight section does. Did you bother reading my just prior post on this topic in reply to footie (#221)? I suppose you might also argue that 1/4 mi trap speed is not very strongly related to power and weight? Good luck with that argument.

A "layman"? A layman at what?
The whole thrust of your theory seems to be that you want to disprove something. That's bad science.
And quit building strawmen. I said nothing about 1/4 mile trap speed.
You can anaylze this stuff until you're blue in the face. Reality seems to differ with your analysis, which probably means your input is off.
Looking at actual repeated experimental data (ie head to head GTR vs 997)
shows the GTR to be a 911 slayer (less the GT2).
And simple logic would dicatate that if a Turbo ran a 7:38 the GTR would be faster.

[footie]

Originally Posted by Garissimo

Then you'll need to reconcile what ever you're basing that assertion on with the telemetry data below.

If another car is pulling away yet doing less speed in the process then what other explanation is there?

If you can answer me that one with a logical answer then I am all ears.

Originally Posted by Garissimo

Here's the telemetry from the 7:29 run (area of interest added by me). Note that the velocity graph is scaled to the min/max of the observed data set. The max is 290 kph. This is about as straight forward as it gets. If you're willing to believe Nissan's 7:29 claim, it should follow that you accept their very own telemetry data, correct?

When the telemetry shows two occasions where the car peaked at 290km/h and it's a total impossibility to reach this speed twice on the ring then I have serious doubts about it's accuracy. The explanation of the car becoming airborne causing the glitch is BS, we aren't talking of the data being captured for a speedo cable.

I prefer to work my opinions and guesstimates on observations and it's as plain as day that the ZR1 continuously was pulling away from the GTR yet never reached the 180mph mark itself. Based on that video evidence I would say the GTR only reach 172~3mph and not the 180mph from the telemetry.

[swamp2]

Originally Posted by footie

I can't say for sure what speed the GTR did but I can say for definite that it wasn't doing 180mph. So maybe all of that number crunching you did swamp looks to have been a total waste of time.

OK we have a direct quote about 180 and the telemetry data this part of the debate is closed. The GT-R hit 180 on the 7:29 run, period.

Originally Posted by footie

I wonder where the 180mph peak speed of the GTR came...

So where exactly did Chris reach his 168.2mph...

Not because this post was particularly relevant but the snippets above in isolation combined with the new telemetry got me thinking about my key assumption that they (of course I mean Chris and Suzuki) would both lift and therefore reach peak speed in a similar location. However, this turns out to be a terrible and incorrect assumption. The telemetry data above (actually used a caliper on my screen) is completely consistent with the GT-R lap video that Suzuki has it pegged until 7:12 and he is not only past the bridge but past Antoniusbuche. He has the sucker pegged through this slight bend. If DR is correct that Chris hit 168 mph at exactly 1800m past the corner exit (seems like some rounding, but I'l take them at their print) that is well before the bridge. This is certainly part, if not all of the reason Suzuki obtained a much higher peak speed. Unfortunately, all of my past work on this in this particular thread is now incorrect because I was assuming they would lift at about the same point. Given that assumption the simulations still stand and the general conclusions about exit speeds still stand as well. I have much more simulation to do now but am off for a long weekend of camping.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

Tire slip.

I know this to be true from experience (drag racing and on-board G meter), but a quarter mile simulation with my loss-leader software confirms a traction-limited car can have a loss of up to several mph in trap speed without major wheel spin (except in the first 60 feet or so).

I've experienced this in stock or nearly stock street Vettes where they'd lose close to 10% of the expected G values in cold weather at around 80 mph or so. Reason: Poor traction from summer sneakers. Likewise, cold (meaning early morning) conditions at a drag strip can subtract from trap speeds, even when starting off in second gear to guarantee initial traction - which by the way tends to raise trap speeds as compared to first-gear launches.

Since the DR test was done on a damp track, this could be a major factor at 100 mph all the way to top speed with cars of this nature. Figure two to three percent slip when optimal, and several times that amount when it's damp.

An interesting point. However, if you recall the tracks line was mostly dry for their final runs. On top of that given how good modern performance tires actually handle wet and dry I seriously doubt wheel slip and or spin is an issue above 100 mph. That takes some serious rear wheel torque just not available in this gear.

Thought you were done? Can't resist, eh?

[swamp2]

Originally Posted by rapistwit

A "layman"? A layman at what?
The whole thrust of your theory seems to be that you want to disprove something. That's bad science.

Well no actually it is you who appear to be a layman by only wanting to use one piece of evidence that is the bad science. Bad science has nothing to do with attempting to prove or disprove it is about the method. As you can see from my post just a few minutes ago we have some new data and I have found a major assumption that was incorrect in my recent analysis. Guess what good science dictates. Admit it and move along.

Originally Posted by rapistwit

And quit building strawmen. I said nothing about 1/4 mile trap speed.
You can anaylze this stuff until you're blue in the face. Reality seems to differ with your analysis, which probably means your input is off.
Looking at actual repeated experimental data (ie head to head GTR vs 997)
shows the GTR to be a 911 slayer (less the GT2).
And simple logic would dicatate that if a Turbo ran a 7:38 the GTR would be faster.

Incorrect. What you are forgetting is that my only firm conclusion thus far is that the GT-R, to run a 7:29, likely has at least 530 hp. This is fairly universally agreed upon here and agreed upon by both those who seem pro Nissan, those accused of being anti Nissan and even those who clearly are anti Nissan. The reason we all seem to agree on this is because of the diversity and abundance of the evidence, including my scientific style investigation.

[footie]

Originally Posted by swamp2

OK we have a direct quote about 180 and the telemetry data this part of the debate is closed. The GT-R hit 180 on the 7:29 run, period.



Not because this post was particularly relevant but the snippets above in isolation combined with the new telemetry got me thinking about my key assumption that they (of course I mean Chris and Suzuki) would both lift and therefore reach peak speed in a similar location. However, this turns out to be a terrible and incorrect assumption. The telemetry data above (actually used a caliper on my screen) is completely consistent with the GT-R lap video that Suzuki has it pegged until 7:12 and he is not only past the bridge but past Antoniusbuche. He has the sucker pegged through this slight bend. If DR is correct that Chris hit 168 mph at exactly 1800m past the corner exit (seems like some rounding, but I'l take them at their print) that is well before the bridge. This is certainly part, if not all of the reason Suzuki obtained a much higher peak speed. Unfortunately, all of my past work on this in this particular thread is now incorrect because I was assuming they would lift at about the same point. Given that assumption the simulations still stand and the general conclusions about exit speeds still stand as well. I have much more simulation to do now but am off for a long weekend of camping.

Thankyou for admitting your early calculation were based on incorrect assumptions and data. Maybe this will go a long way to believing that Suzuki's car wasn't outperforming Chris's car in acceleration at the very least and that Suzuki himself is a God among test pilots.

[swamp2]

Originally Posted by footie

Thankyou for admitting your early calculation were based on incorrect assumptions and data. Maybe this will go a long way to believing that Suzuki's car wasn't outperforming Chris's car in acceleration at the very least and that Suzuki himself is a God among test pilots.

No need to say thanks. I just hope that folks do see my open mindedness and focus on truth above bias and brand. Like I said lots of simulation work to do now. I'm actually excited to do that. I never doubted Suzuki's skills, nor did Chris for that matter, but this important point does seem to have been overlooked.

If you recall my previous analysis should still be valid since I purposefully chose a location even before the bridge to compare all of the cars since the ZR1 lifted pretty early.

[footie]

Originally Posted by swamp2

No need to say thanks. I just hope that folks do see my open mindedness and focus on truth above bias and brand. Like I said lots of simulation work to do now. I'm actually excited to do that. I never doubted Suzuki's skills, nor did Chris for that matter, but this important point does seem to have been overlooked.

It take a big man to admit you got something wrong, I recall myself only going it one or twice and probably all of those don't as a PM. Anyway I look forward to your new and hopefully improved data comparing Chris's GTR data with Suzuki's GTR data to see if they aren't so far apart after all.

Originally Posted by swamp2

If you recall my previous analysis should still be valid since I purposefully chose a location even before the bridge to compare all of the cars since the ZR1 lifted pretty early.

Yeah you are right and funny your mention that I too recall myself saying something along the line of Suzuki seems to pull back a tiny bit on the ZR1 between the bridge and the finish line (or maybe I just imagined that ).

[bruce.augenstein@comcast.]

Originally Posted by swamp2

An interesting point. However, if you recall the tracks line was mostly dry for their final runs. On top of that given how good modern performance tires actually handle wet and dry I seriously doubt wheel slip and or spin is an issue above 100 mph. That takes some serious rear wheel torque just not available in this gear.

Doubt if the track was even close to the same condition as when the Nissan guys attacked it. Wheelspin is not what I was addressing, but wheel slip is omnipresent, from any speed to any other speed. If you're putting any amount of torque to the tires, they're slipping. It's just a question of how much - and that's my point. There are real differences here.

Originally Posted by swamp2

Thought you were done? Can't resist, eh?

Finally, somone (you) brought in new data, instead of just rehashing tired old stuff with some real idiots joining the fray.

I personally don't feel as if wheel slip variations could account for the differences in speed that you noted, but absolutely believe a good percentage of that difference might lie there, with the rest accounted for by normal atmospheric changes and car to car variations in performance.

Note that car to car variations (not just horsepower) can be significant in any car - not just the GT-R. Witness the variations I've seen in M3 quarter mile published times. All the way from 12.5 at 114 (R&T) to 13.2 @ 106 (Autoweek). A fair bit of these variations can be ascribed to conditions, but not even close to all.

[rapistwit]

Originally Posted by swamp2

Well no actually it is you who appear to be a layman by only wanting to use one piece of evidence that is the bad science.

How did you arrive at me only using one piece of evidence?
I have stated over and over again that every review I've come across concludes the GTR is quicker than a 997 Turbo and GT3. Add to that Porsche claims a 7:38 with Turbo a sub 7:30 doesn't seem out of reach for the Nissan.
Porsche's Nordscheife claims inadvertantly gave more weight to Nissan's claims.
And I have stated that I have run my 3800lbs/500bhp/465lbft CLK63 Black against my 3800lbs/480bhp/430lbft Nissan and the GTR absolutely destroys the Mercedes.
I think I have a more solid scientific footing than anyone dissecting a DR run in GTR.

[Garissimo]

Originally Posted by footie

If another car is pulling away yet doing less speed in the process then what other explanation is there?

If you can answer me that one with a logical answer then I am all ears.

Which two cars are you referring to? If you mean the ZR-1 on its 7:26 lap and the GT-R on it's 7:29 lap, the videos show both cars covering the same distance (using the red Audi banner and the concrete Bilstein bridge as markers) in a little over 23 seconds. I've looked at both videos in depth and what's shown supports my contention.

Originally Posted by footie

When the telemetry shows two occasions where the car peaked at 290km/h and it's a total impossibility to reach this speed twice on the ring then I have serious doubts about it's accuracy. The explanation of the car becoming airborne causing the glitch is BS, we aren't talking of the data being captured for a speedo cable.

Let's get this straight, you ridicule the notion that a wheel speed sensor could be used to capture speed (presumably because it wouldn't be accurate) and then go on to doubt the accuracy of a GPS based system? You believe Nissan when they tell you a "stock" GT-R managed a 7:29 lap but you don't believe their telemetry data from that run. You employ a very selective, illogical method of deduction.

Regardless, I e-mailed Jethro Bovington at Driver's Republic and he was kind enough to indulge my questions. Without describing the equipment in detail he told me that Nissan uses a full race telemetry system and their data is accurate. He went on further to say that Nissan actually recorded a peak speed of 180.2mph on the back straight for that run. I don't have his permission to copy and paste the e-mail exchange so I'm not going to post it here but he was the one who wrote the article on Nissan's 7:29 run and interviewed the GT-R's chief engineer. He also expressed amazement that the "stock" 480 hp was able to post a faster top speed on the back run than the 638hp ZR-1. He told me to stay tuned, because they would be doing a follow on ring test with the GT-R this summer.

Originally Posted by footie

I prefer to work my opinions and guesstimates on observations and it's as plain as day that the ZR1 continuously was pulling away from the GTR yet never reached the 180mph mark itself. Based on that video evidence I would say the GTR only reach 172~3mph and not the 180mph from the telemetry.

Your "geusstimates" aren't as convincing as Nissan's telemetry data.

[footie]

Originally Posted by Garissimo

Which two cars are you referring to? If you mean the ZR-1 on its 7:26 lap and the GT-R on it's 7:29 lap, the videos show both cars covering the same distance (using the red Audi banner and the concrete Bilstein bridge as markers) in a little over 23 seconds. I've looked at both videos in depth and what's shown supports my contention.

On this I am in total disagreement and so is Swamp, Bruce and a heck of a lot more. It's as plain as day that the ZR1 was pulling away from the start of the straight until the bridge, now what happened after the bridge is harder to determine but according to Swamp he is of the opinion that Suzuki never lifted until well past the curve after the bridge and on watching the ZR1 lap you can plainly see the Vette driver lift. This may explain how the GTR peaked higher but I am 100% certain that prior to the bridge the GTR was comfortably slower than the Vette and produced a speed more in line with the GTR Chris drove.

Originally Posted by Garissimo

Let's get this straight, you ridicule the notion that a wheel speed sensor could be used to capture speed (presumably because it wouldn't be accurate) and then go on to doubt the accuracy of a GPS based system? You believe Nissan when they tell you a "stock" GT-R managed a 7:29 lap but you don't believe their telemetry data from that run. You employ a very selective, illogical method of deduction.

Read above.

Originally Posted by Garissimo

Regardless, I e-mailed Jethro Bovington at Driver's Republic and he was kind enough to indulge my questions. Without describing the equipment in detail he told me that Nissan uses a full race telemetry system and their data is accurate. He went on further to say that Nissan actually recorded a peak speed of 180.2mph on the back straight for that run. I don't have his permission to copy and paste the e-mail exchange so I'm not going to post it here but he was the one who wrote the article on Nissan's 7:29 run and interviewed the GT-R's chief engineer. He also expressed amazement that the "stock" 480 hp was able to post a faster top speed on the back run than the 638hp ZR-1. He told me to stay tuned, because they would be doing a follow on ring test with the GT-R this summer.

Please sent the e-mail by PM if not wanting to release it on the forum, I promise I will handle it with care but I really would like to read what JB wrote.

Oh and I look forward to reading their follow up to the GTR vs GT2 article, hopefully we will see something more concrete because the previous article threw up more questions than answers.

Originally Posted by Garissimo

Your "geusstimates" aren't as convincing as Nissan's telemetry data.

As I and Swamp both made the mistake of thinking that Suzuki's peak speed happened before the curve and not after it I couldn't/shouldn't believe that it out accelerated the ZR1 both this point on the track and based on the telemetry that is a correct assumption because the GTR's peak happened after the ZR1's peak meaning it took more track and time to reach that speed.

When I am wrong I will admitted and like Swamp I assumed wrong with regards to the telemetry. But I will add that this is the only thing I believe I am wrong on, all else especially the output and whether or not it's identical to every other GTR (output wise) is still correct.

Bob.