Nissan GT-R Spec V

[sirwilliam]

Yeah, it gets even better: R&T ARTICLE

Zero to 60 mph will be near 3 seconds flat...on a cool day on an ideal driving surface, it may even break into the 2s.

I can't remember if this was already posted but I thought I would share one more...okay, now back to work!

[complacent]

It's difficult to figure out exactly how this car does the things that it does with the laws of physics...

wow, just wow.

[Libra Monkee]

I don't know why bu something about an FTL Drive just popped in my head.

[GaToR]

AWD is a performance goldmine for supercars that is finally being tapped in full.

[chicken n waffles]

0-60 in high 2s = pants suddenly tighter

[complacent]

0-60 in high 2s = pants suddenly tighter

I don't think I could count to 60 that fast.

[avriette]

AWD is a performance goldmine for supercars that is finally being tapped in full.

Somewhere along the way somebody stopped trying to make RWD/FWD work. It's pretty telling that with the GT-R the reviewers complain about it being neutral tending towards understeer. I don't think that AWD is inherently any faster than FWD or RWD, but it's easier to sort out.

[GaToR]

AWD is a performance goldmine for supercars that is finally being tapped in full.

Somewhere along the way somebody stopped trying to make RWD/FWD work. It's pretty telling that with the GT-R the reviewers complain about it being neutral tending towards understeer. I don't think that AWD is inherently any faster than FWD or RWD, but it's easier to sort out.

Though there is a lot of evidence to support you, I disagree whole-heartedly. I think there is no competition to a well-sorted out AWD system with all other factors being equal.

Sure, anything ultra-lightweight with huge tires and/or tremendous downforce makes AWD unnecessary. F1 will never make use of AWD. But at what point does it become impossible to put all that on a road car? AWD acts as a substitute for one of those factors. In the GT-R's case, they just said to hell with an extra 600lbs over the GT2.

But throw it all together: downforce + lightweight + tire surface area + weight distribution + AWD, it absolutely destroys the competition.

I use Alzen racing as an example. The fastest Group A Porsche ever to run a 24-hours of Nurburgring lap was the 996 GT2 Turbo 4WD. 6:40 on the Norsdschlieffe. No other homogolated car to my knowledge has even come close. Including their own GT3.

What's the GT2 to do at this point? Get more aerodynamic? Shave a few more lbs? Add a few more hp? Well, the GT-R can get lighter, sleeker, more powerful too. And it will always stay ahead so long as its traction aids keep up with the changes made.

I guarantee if Porsche threw together a rigorously tested GT2/Turbo hybrid it would obsolete both the current GT2 and the Turbo. Stripped GT2 weight and aerodynamics with Turbo traction = WIN. There's no reason at all why Porsche's 998 Turbo can't be faster than the GT-R from a technical standpoint. Honestly I think they are sandbagging it to legitimize the GT2 for the purists' sake.

The GT-R might edge on the side of understeer. I don't know about the rest here, but I wouldn't settle for what Nissan told me the car was supposed to feel like. Thats just not our nature

I predict that within the next several iterations of the GT-Rs and the NSXs and the R8s and the Turbo's that RWD will be like manuals. Sure its more fun to drive them, but it costs you seconds/lap.

[avriette]

Though there is a lot of evidence to support you, I disagree whole-heartedly. I think there is no competition to a well-sorted out AWD system with all other factors being equal.

I'd just like to point out that all things are never equal.

Let me make a corollary to the argument, though. The Sukhoi Su-47 and Grumman X-29 both have a hyperswept wing. This is inherently very unstable configuration. Engineers, however, were able to make the aircraft "behave" more stably by using advanced controls and avionics. Because of this instability, the aircraft is actually more maneuverable. While we would normally think of a system that was inherently unstable as not an effective way to get around, engineers were able to make it work by understanding the actual dynamic of the vehicle. This "dynamic instability" actually became an asset to the aircraft when the engineers made it possible for pilots to use.

It's always possible to make a vehicle "handle better," or have a better weight distribution (see, for example, the switch to a rear-mounted transmission in the Corvette; conversely, the rear-engine, rear-drive Porsches were made to understeer through suspension adjustments). The reason we go with AWD, rather than improving a RWD platform is that it is easier to do so, rather than due to some inherent advantage of AWD.

In fact, "all things being equal," I think most people would agree that AWD actually has a lot of disadvantages. The most obvious disadvantages being weight and complexity, and more subtle disadvantages such as drivetrain losses and cost.

At any rate, manufacturers will continue to use AWD, despite the drawbacks, because people just can't drive well enough to be trusted with a ... dynamically unstable vehicle.

I think these principles change somewhat between tarmac and gravel (but who actually takes their GT-R rallying?).

I predict that within the next several iterations of the GT-Rs and the NSXs and the R8s and the Turbo's that RWD will be like manuals. Sure its more fun to drive them, but it costs you seconds/lap.

People buy these cars because they're fun to drive. Why would somebody complain about a GT-R understeering when it was murdering the competition? All things being equal, wouldn't they have just said "boy, this pig sure is fast" and not have pointed out the unusual handling and poise?

Arrrrrr.

[GaToR]

I think we've implicitly agreed to disagree, but at least we can have fun with it.

I think the reason for stability in a car is that with all the obstacles one has to face at 150mph while cornering, the more work the car does, the faster you get to go. There just comes a point, as we know when human reaction times become inferior to mechanicals. Like essentially all racecars having manuals that get shifted for you.

AWD is like thrust-vectoring with FBW. It can change the direction of the vehicle in question with throttle inputs. Thats the reason both the US and Russian AF dumped FSW designs for production aircraft, because any aircraft or missile that steers the thrust of the vehicle is inherently more maneuverable under any AoA. To the point where wing design become irrelevant.

Likewise, testers of the GT-R have said that you can throw it into corners harder and power out harder than any other vehicle they've ever driven. You put the thrust to work in the direction you want to go, and the computers sort it out for you. You maintain more speed through corners. Just like an F-22.

In fact, "all things being equal," I think most people would agree that AWD actually has a lot of disadvantages. The most obvious disadvantages being weight and complexity, and more subtle disadvantages such as drivetrain losses and cost.

Again, I think this is very conventional thinking on the subject. 20 years ago I would agree, the advantages and disadvantages would roughly equal out. But what Porsche has started with the 959 was minimizing the disadvantages, and maximizing the advantages, so that Nissan adding it to the GT-R was like giving the R32 steroids.

The reason I think the GT-R is heavy is its a BIG car. Weight difference between Carrera 2 and Carrera 4? Less than 100lbs. Actually I think its more like 75. IMO, the traction advantage is well worth 75 lbs, if there's a computer to compensate for the instability added (understeer) of the AWD version. If the Carrera 4 or the 335xi had Mitsu or Nissan's AYC, etc, they should kick the snot out of their respective 2wd counterparts.

Like I said, it was all true up until now. But we are at the break point. I don't think AWD is easier on the manufacturer, nor too complex, nor that much more costly, nor heavy. I think its disadvantages are becoming so minute and the advantages so great that from a cost/benefit analysis standpoint, Acura couldn't say no for example.

I seriously ask, what can they do to make the already uber-light and powerful GT2, Corvette, or Viper significantly faster, that cannot also make the GT-R faster? I don't think they are slacking off with that design, or have forgotten how to engineer. I honestly think the performance of practically-sized cars with RWD is tapering off. There will always be room for the Zonda's and Saleen S5's and Exiges to improve, but who wants to drive that every day?

They can rebuild the whole thing from carbon-fiber, or add a rediculous wing for street use. Or just add 100lbs and an AWD system. And frankly, the answer to all 3 is 'yes'. They compliment each other.

I don't think RWD will be able to indefinitely compete without superior downforce. People will enjoy it more. Its more adrenaline inducing on the edge. And I believe them after reading one review of a GT2 driver fearing for his life.

And from what the purists are saying, thats the exact definition of the GT-R 'sure the pig isn't as fun, but it is fast.'

[avriette]

I think we've implicitly agreed to disagree, but at least we can have fun with it.

Of course. I mostly agree with everything you said.

Likewise, testers of the GT-R have said that you can throw it into corners harder and power out harder than any other vehicle they've ever driven. You put the thrust to work in the direction you want to go, and the computers sort it out for you. You maintain more speed through corners. Just like an F-22.

I think you can make the argument here that if you're going to go FBW, you can make the vehicle behave just about any way it is capable of behaving in response to driver input.

Again, I think this is very conventional thinking on the subject. 20 years ago I would agree, the advantages and disadvantages would roughly equal out. But what Porsche has started with the 959 was minimizing the disadvantages, and maximizing the advantages, so that Nissan adding it to the GT-R was like giving the R32 steroids.

You're absolutely right that the "penalty" for the AWD system is dramatically reduced of late. I'm curious what you would think of an AWD Elise.

Weight difference between Carrera 2 and Carrera 4? Less than 100lbs. Actually I think its more like 75. IMO, the traction advantage is well worth 75 lbs, if there's a computer to compensate for the instability added (understeer) of the AWD version.

Are you saying that the addition of two more drive wheels on adds 75lbs to the vehicle? The only way I see this being true is the 2WD vehicle having most of the AWD stuff already, and the difference between the two being something as simple as halfshafts. But then, I'm not a Porsche guy.

Like I said, it was all true up until now. But we are at the break point. I don't think AWD is easier on the manufacturer, nor too complex, nor that much more costly, nor heavy. I think its disadvantages are becoming so minute and the advantages so great that from a cost/benefit analysis standpoint, Acura couldn't say no for example.

Again, I agree, but I think what you're getting at here is we've advanced to the point with automobile dynamics that a manufacturer can pick an arbitrary drivetrain configuration and make it work far better than the sum of its parts would imply.

And I believe them after reading one review of a GT2 driver fearing for his life.

I think it's probably in the DSM (er, the other other DSM), but this is generally what I look for in a car.

And from what the purists are saying, thats the exact definition of the GT-R 'sure the pig isn't as fun, but it is fast.'

Yeah. Boils down to preference, I suppose. I'm the guy that wants to gut the AWD in the STI and make it handle worse.

[GaToR]

I think you can make the argument here that if you're going to go FBW, you can make the vehicle behave just about any way it is capable of behaving in response to driver input.

I think what you're getting at here is we've advanced to the point with automobile dynamics that a manufacturer can pick an arbitrary drivetrain configuration and make it work far better than the sum of its parts would imply.

In a nutshell, yes. What really makes the GT-R a world-beater? Its brain. Taking all of its stregths and weaknesses into account 100 times/second, and having the tools to keep it on-course is what separates this from the herd.

Are you saying that the addition of two more drive wheels on adds 75lbs to the vehicle? The only way I see this being true is the 2WD vehicle having most of the AWD stuff already, and the difference between the two being something as simple as halfshafts. But then, I'm not a Porsche guy.

For a 3200lb car with less than 400hp, yes. Obviously it would increase with load.

Sorry for the low-quality, this is a screenshot from a flash on their site:



What you see in this picture is all 75lbs added to the front of the car to handle 40% of its torque on demand. Its not like they handicapped the C2. They just found the minimum to add to the C4.

Starting from the C2's rear transaxle, it adds a driveshaft, a clutch, a front differential and CV shafts. You can't see here, but in comparison to the rest of the vehicle, this little 1-speed gearbox setup looks SMALL! It only has to handle 150lb-ft of torque once in a while. And they built it accordingly, very efficient.

I think this is the future of AWD, replacing center differentials and transfer cases. It explains why Nissan claims drivetrain loss comparable to RWD cars.

Unlike the previous ATTESA systems which relied heavily on mechanical feedback, the system in the GT-R uses electronic sensors and hydraulically-actuated clutches. It also has a yaw-rate feedback control system, effectively managing slip angle.

This might also explain why Porsche's AWD is not a performance advantage over its RWD models... yet. The viscous coupling prevents wheel slip, but it is not electronically linked to driver inputs. So it helps in the wet, but doesn't shoot you around corners. Don't be shocked if they figure that one out for the 998. This same methodology could work for Acura, Audi, BMW, Lambo, or anyone making an AWD supercar. You saw it here first, with Nissan.

I'm curious what you would think of an AWD Elise.

I think if you took and equivalent to ATTESA-ETS and built it from the ground-up on a <2500lb car with significant downforce and tremendous contact patch, you'd see something remarkable beyond our wildest expectations.

[ElZorro]

Got to see my first GT-R this weekend, at Hyperfest. Pictures up at: http://gallery.dcawd.com/main.php?g2_it ... =x6608d8a6