GT-R MASSIVELY under-rated

[dechoong]

Originally Posted by Hans Delbruck

I know I won't feel inadequate when I'm at a stoplight and a GT-R pulls up, then blows my M3 away. The GT-R has more HP and AWD, of course it's faster. Why the agony here? The M3 can't be the champ at everything, but it might be the perfect car depending on what you're looking for.....

Well said

[dechoong]

Originally Posted by Champagne

I really don't care, because it's a Nissan. Hence my previous post!

Could never ever bring myself to own a Nissan.

I don't know much about the latest Nissans, but the 300Z in the 90s is one of the best car I've driven... solid drivetrain with impeccable built quality.

Though BMWs are considered a premium product, they do produce some crap like the Z3.

[Robert]

Originally Posted by Champagne

They could make the car do 0-100 in 2 seconds, still... I really can't be asked to own a Nissan.

We need a sticky thread for these comments...


aka:
"more than you can afford pal, ferrarriiii"

reference:

[sdiver68]

Originally Posted by swamp2

Many of the folks on the power to weight vs. N'Ring regression thread and others on the thread about the 7:38 time as well. Many believed without a shred of skepticism that the 7:38 time and the amount the GT-R was an outlier in the regression analysis were points to simply be discarded. Not to mention Nissan fanboys all over other forums all over the internet.

No, what was to be disregarded was the HP/weight ratio that was published. Some of us knew that the whole time.

[Champagne]

Originally Posted by lucid

Why not? What's wrong with owning a Nissan? I've owned two 300ZXs, and they were great sports cars. They were much more fun to drive than my current BMW 325ci. The BMW name itself does not add anything to the experience. I guess you wouldn't want to own a twin turbo Supra either since that's a Toyota. How about a Corvette? That's made by GM. So, that's probably not good enough either.

Both times I've driven a Nissan they've broken down. They where both rental cars (thank god) with full insurance. That's why I would never own a Nissan.

Had the most awful experience in Marbella because of a break down. Try to explain that the car has broken down on the motorway when they don't speak English.

I realize that these where rental cars, and may not have been treated very nicely, but it was a rather new car!

Also, I'm gown up with BMW which makes me love them even more. That may be the reason why I never had a problem with the I-Drive, as so many people seem to have (especially during reviews (hint, Jeremy Clarkson)).

[Champagne]

Originally Posted by bobbo

We need a sticky thread for these comments...


aka:
"more than you can afford pal, ferrarriiii"

reference:

Hey man, if you want to know my reason for feeling the way that I do, ask! You don't have to respond with insults.

EDIT: After watching that video I might have taken your inlined quote a little to hard, thought it was a direct insult on me.

[Champagne]

Originally Posted by ruff

Logic in a sea of bias.



This is the badge blinded rubbish that makes the serious BMW enthusiast shudder. BMW once again finds it's new target market and adds more fuel to the BMW poseur jokes within industry.

It's not the badge. It's the quality of what the badge is place upon.

[sdiver68]

Originally Posted by Champagne

It's not the badge. It's the quality of what the badge is place upon.

I've own a Nissan Frontier truck and owned 2 Infinitis, '03 FX35 and '06 M45 Sport. I've never had any bad issues, although I will say IMHO overall build "solidity" is not quite to BMW standards.

[Champagne]

Originally Posted by sdiver68

I've own a Nissan Frontier truck and owned 2 Infinitis, '03 FX35 and '06 M45 Sport. I've never had any bad issues, although I will say IMHO overall build "solidity" is not quite to BMW standards.

Well... When you've had 2 cars break down on you. You really can't bother me for my thoughts about them? Of course since both where rentals, probably loads of bad luck, I should not judge them all at the same time. But it's hard to feel good about 'em after these experiences.

Therefore I really can't be asked to depends on a Nissan for my everyday use!
I'm sure you all feel like this about a specific brand.

[Epacy]

Placing your whole perception of a car company based on two rentals is extremely inaccurate.

[Champagne]

Originally Posted by Epacy

Placing your whole perception of a car company based on two rentals is extremely inaccurate.

I'm well aware of that, even so you can't ask me to depend on a car that on two separate occasions have broken down, would you? I would choice a BMW any day. There's also, on a different note, not so many service places for Nissan in Sweden.

And it's just one persons opinion, seems like you value mine quite a lot *feeling warm and fuzzy*

[gbb357]

Champagen, you're not seriously telling me that BMW in general is more reliable than Nissan just because of two rentals that where bad. C'mon now, let's be real.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Bruce, true or false, AWD systems exhibit significantly larger drivetrain losses than RWD vehicles of a similar component quality? Also true or false, a transmission located at the rear of a vehicle with an extra drive shaft to get power back up front also creates more losses than not having those components? Last but not least, true or false. Running a simulation assuming the GT-R is a RWD vehicle (which is what Quarter Jr. is doing) will fairly drastically underestimate the drivetrain losses of the vehicle?

Conclusion: Quarter Jr. software is not a very reliable judge of a AWD + rear tranmissioned vehicle since it misses out on a significant amount of loss the car will have.

Underestimating the drivetrain loss by only 5% (using the rough but reasonable estimate that RWD total drivetrain loss is approx. 15% and AWD is approx. 20%) could make Quarter Jr. underestimate the under-rating of the car by that same 5% of the vehicles total power or about 25 hp.

Can't argue any of these points, at least not conceptually. There may in fact be a minor mitigating concept a la Audi's SAE paper way back when, showing that driven wheels have lower rolling resistance than those that are just along for the ride. However, AWD cars will in fact have more restance to the engine's urges, can't deny it.

OK, back to the drawing board.

I fire Quarter, Jr. up, and plug in the numbers from the C & D 911 Turbo Tiptronic "Short Takes" test last year. They got an 11.6 @ 122, 0-60 in 3.4 seconds.

Result: The simulation shows an 11.62 ET, crossing the finish line at 121.5 mph, with an 0-60 time of 3.39 seconds. Wow!

Doing my sums, the Porsche may be underrated by (TA DA!) about six horsepower, as opposed to the 12 horsepower I calculated that those bastards at Nissan weren't telling us about.

Swamp, this is all approximate stuff, and I'm not waxing poetic about Quarter, Jr. (it is in fact the cheapie loss leader from RSA, after all). The thing is, there are some items out there (as previously mentioned and as this lightweight testing seems to show), indicating that the GT-R may not be as "MASSIVELY under-rated" as you are saying.

I know that once you take a stand, dynamite won't blow you off that perch, but I'm thinking that's a precarious perch indeed.

As I said, the jury still seems to be out.

Bruce

PS - Once the GT-R is available in the U.S. with published numbers, I'm thinking that Nissan will have to be doing some very interesting things to fool the SAE guy who is hawkishky watching the dyno tests. Once the SAE observer signs off, then and only then does Nissan get to advertise the results.

[Champagne]

Originally Posted by gbb357

Champagen, you're not seriously telling me that BMW in general is more reliable than Nissan just because of two rentals that where bad. C'mon now, let's be real.

C'mon now, let's be real and start reading my posts thoroughly.

What I've been saying all alone is that I'm not going to live with a car that my gut doesn't like because of two rental brake downs. What's so terrible with me leaving my own personal opinion about Nissans? I've had a couple of bad experiences with a specific brand, and I don't want to live with a car with that badge on it.

That's all I've been saying all along.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

Can't argue any of these points, at least not conceptually. There may in fact be a minor mitigating concept a la Audi's SAE paper way back when, showing that driven wheels have lower rolling resistance than those that are just along for the ride. However, AWD cars will in fact have more restance to the engine's urges, can't deny it.

OK, back to the drawing board.

I fire Quarter, Jr. up, and plug in the numbers from the C & D 911 Turbo Tiptronic "Short Takes" test last year. They got an 11.6 @ 122, 0-60 in 3.4 seconds.

Result: The simulation shows an 11.62 ET, crossing the finish line at 121.5 mph, with an 0-60 time of 3.39 seconds. Wow!

Doing my sums, the Porsche may be underrated by (TA DA!) about six horsepower, as opposed to the 12 horsepower I calculated that those bastards at Nissan weren't telling us about.

Swamp, this is all approximate stuff, and I'm not waxing poetic about Quarter, Jr. (it is in fact the cheapie loss leader from RSA, after all). The thing is, there are some items out there (as previously mentioned and as this lightweight testing seems to show), indicating that the GT-R may not be as "MASSIVELY under-rated" as you are saying.

I know that once you take a stand, dynamite won't blow you off that perch, but I'm thinking that's a precarious perch indeed.

As I said, the jury still seems to be out.

Bruce

PS - Once the GT-R is available in the U.S. with published numbers, I'm thinking that Nissan will have to be doing some very interesting things to fool the SAE guy who is hawkishky watching the dyno tests. Once the SAE observer signs off, then and only then does Nissan get to advertise the results.

OK first of all MASSIVE and in all caps may have been a bit dramatic/overstated, maybe even a bit premature. There is, however, multiple forms of evidence pointing to an under-rating. Part of the reason for my word choice was based on the dyno results showing basically the claimed crank output at the wheels. I was a bit short sighted on the subtleties of that particular dyno in that it typically gives figures much higher than other dynos. However, even if it rates things about 10% too high with a 20% total drivetrain loss, the GT-R still comes in at 530+ crank hp, and I guess I would still call that massive. The N'Ring regression analysis also points to the possibility of a fairly substantial under-rating (or a variety of other effects working in tandem such as great driver+DCT+great tires ... or alien technology of you prefer that explanation ...). The last piece of evidence is the 1/4 mi time and it too point to under-rating (the number I have heard is 11.7s). I'm not sure how much more evidence we will need.

Back to the simulations. Getting fantastic agreement from a simulation vs. test results may happen but it may also be a case of getting it right for the wrong reasons. I'm fairly sure this is the case for your 911 Turbo results. If Q. Jr. can predict RWD times in a reasonably well validated fashion and it has absolutely no wasy to account for AWD, then it simply (almost by definition) can not also get AWD performance figures accurate for the right reasons. Doesn't this make fundamental sense? We all know and understand that AWD cars get a harder launch but then suffer much greater parasitic drivetrain losses which hurts the cars performance more at higher speeds. You can not just rely on a simulation tool blindly and rely on it as a black box to just turn the crank, get the answer and not question the results in any way. It appears that this is what you are doing here. "Responsible" and intelligent use of simulation DEMANDS contstant questioning of the model, the inputs and results. CarTest offers complete control of a huge number of input variables including FWD, RWD, AWD and a plethora of other user defined inputs (you can see some screen grabs of the amazing number of inputs possible in CarTest on other threads here on the forum). One reason I am a bit hesitant to use and post results for cars like the 911 and GT-R is that I have not had great luck simulating Turbo charged cars yet. I will probably work a bit more on the 335i and making sure I can get good results for known/justifiable reasons before relying on CarTest too much for such cases. In any case I think my preliminary runs with CarTest for the GT-R showed it required about 520 hp to get a 3.5s 0-60 and 11.7 1/4 mi. I did use very short 0.03 s shifts as we can expect from its dual clutch system and of course the AWD option.

[footie]

Originally Posted by swamp2

OK first of all MASSIVE and in all caps may have been a bit dramatic/overstated, maybe even a bit premature.

If only you had given me the same decent courtesy that Bruce has gave you when I said 'Most advanced car in the world'.

Swamp, things do work both ways.

[footie]

Originally Posted by swamp2

In any case I think my preliminary runs with CarTest for the GT-R showed it required about 520 hp to get a 3.5s 0-60 and 11.7 1/4 mi. I did use very short 0.03 s shifts as we can expect from its dual clutch system and of course the AWD option.

Officially from Nissan they say the shift times are 0.2s and not 0.03s but they also say it's official output is 480hp.

But after reading is review in EVO they said that it's shifts were much more noticeable than VAG's DSG box so chances are it is higher than the 0.03s you used as you estimate.

[swamp2]

Originally Posted by footie

If only you had given me the same decent courtesy that Bruce has gave you when I said 'Most advanced car in the world'.

Swamp, things do work both ways.

:sad0147:

Well maybe the same to you, not to me.

1. One issue concerns one specification for one car, the other is a brash statement about ALL cars placing one above all others. This type of absolutist statement will surely be subject to great scrutiny and debate. Seems so obvious to me. It is like saying XXX is the best athelte of all time, or YYY was the worst president ever.
2. There is ample evidence that the GT-R is under-rated and evidence as well that it is massively under-rated. As well I directly provided evidence for this statement in my post. In comparison you made the statement, provided no evidence and struggled when questioned/callled out.
3. I am always willing to withdraw/revise/update/change my opinion as new facts come to light. Are you?

back at you!

[swamp2]

Originally Posted by footie

Officially from Nissan they say the shift times are 0.2s and not 0.03s but they also say it's official output is 480hp.

But after reading is review in EVO they said that it's shifts were much more noticeable than VAG's DSG box so chances are it is higher than the 0.03s you used as you estimate.

Either way .2 s shift for a dual clutch would be absurd. Good humans can shift in ~.25 s, a great autobox in ~.1, Ferraris new sequential in ~.05 s and DSG from Audi/VW (likley) shifts in .03 s. The quote directy from Nissan that their system takes .2 s to shift is probably a typo and surely is incorrect. Even if their system "sucks" as far as shift time and is worse then Ferarris sequential (which is not a dual clutch) it may be ~.07s. Using .03 in my simulations would then be in error .04 s per shift. This is absolutely insignificant.

The key thing as far as the simulation goes is that CarTest uses a std. shift time of .5s for a MT, not counting clutching time which is counted separately. I use .2-.3 for my std. MT simulations with .05-.1 for clutch operations. The key here is that any DCT should shift about 10 times faster than this. Get it anywhere in that ball park and you are good to go. So the lesson here is why fuss about the milliseconds when you are shooting for and expecting simulation accuracy of tenths of seconds?

Last but not least a more "noticeable" shift is not synonymous with a slow shift. They are related but there are other factors involved as well.

[footie]

Originally Posted by swamp2

Last but not least a more "noticeable" shift is not synonymous with a slow shift. They are related but there are other factors involved as well.

I hate this because you know the reaction you will get but here go.

Sorry swamp to disagree with that one, if it's shift time is close to the DSG then you are completely and totally wrong with your opinion that it's being noticeable is not to do with shift time, to understand the reason why Audi's DSG box isn't noticeable is because that is no drop off in power the shift from one gear to another is seamless, as one gear is driving the car the other is spooled up and spilling at the exact speed ready to take over.

For one reason or another Nissan has chose to give a gap that is a bit more noticeable, probably to help protect the transmission from the power but even that is not a logical answer because the Veyron uses a version of Audi's DSG and even with it's conservative 1000hp to shift are done without notice.

We will probably never know why it's the case but it's most definitely to do with shift time and the clutches involved.

[swamp2]

Originally Posted by footie

I hate this because you know the reaction you will get but here go.

Sorry swamp to disagree with that one, if it's shift time is close to the DSG then you are completely and totally wrong with your opinion that it's being noticeable is not to do with shift time, to understand the reason why Audi's DSG box isn't noticeable is because that is no drop off in power the shift from one gear to another is seamless, as one gear is driving the car the other is spooled up and spilling at the exact speed ready to take over.

For one reason or another Nissan has chose to give a gap that is a bit more noticeable, probably to help protect the transmission from the power but even that is not a logical answer because the Veyron uses a version of Audi's DSG and even with it's conservative 1000hp to shift are done without notice.

We will probably never know why it's the case but it's most definitely to do with shift time and the clutches involved.

OK, let's keep the disagreement going. My belief is that there is no necessary/causal connection between shift time and percieved shift roughness. The evidence is out there for this, both

VW/Audi DSG: Shift times are probably .03 s yet also seem to offer fantastic smoothness. If shorter shifts mean rougher shifts then DSG is the direct proof against that. Granted a dual clutch system is not quite the same as a traditional clutch system.

Ferarri/BMW: Their old sequential (non dual clutch, automated manual, say in the F360) had reasonably quick shifts, I'm not sure the time off hand but faster than a human for sure. This system was also known for being quite rough/jerky. SMG II on the E46 M3 especially in the more aggresive manual shift modes only shifted in about .2-.25 seconds (total shift time, counting both clutching operarations). This time is not so fast it is more known imply for its amazing consistentcy. Despite the time not being so fast it is also quite a rough shifting system. Again WOT shifts, at redline, in an aggresive shift mode reall is a "neck snapper". Again going back to the new sequential in the Scuderia we incredibly fast shifts, certainly faster then the F360 system yet at the same time is is smoother!

Back to the non emperical, engineering type of evidence. There are many reasons for a shift being smooth or rough. Part of the issue with a SMG or a MT system is that is has to fully cut engine power (I'm sure it does this by simply cutting engine spark rather than letting up the power by throttle control), then perform clutch dis-engage, then shift, then clutch engage, then bring the power back on. This process gives you the large deceleration followed by the large acceleration, hence the jolt. With Ferarri it appears they have outsmarted the jolt in some way through a clever sequencing and control of the above events. DCT is a whole different beast. It obtains smoothness by keeping the power to the wheels almost continuosly through simultaneous clutch disengage and engagment on the other clutch. As engima pointed out any system system still has to accomodate the absorption of energy that goes along with a large change in rmp of the engine and transmission components and the flywheel weight is an important factor here as well.

We also know that various flavors of DCT systems, VW/Audi vs. Mitsubishi vs. Nissan offer varying levels of smoothness. It is fairly obvious that a small, low hp engine can obtain a smoother shift than the high performance/high power vehicle.

So again, based on an understanding of the systems themselves, as well as what various manufacturers have actually obtained with the various systems I think it is reasonable to claim the shift time does NOT directly correlate with shift smoothness.

[lucid]

Originally Posted by swamp2

(I'm sure it does this by simply cutting engine spark rather than letting up the power by throttle control)

Wouldn't that result in an emissions nightmare as you'd be spewing out unburnt fuel each time you shift?