How Much Power Does the Nissan GT-R Really Have?

[footie]

Bruce,

There is an optimum way of getting a rwd car off the line and it's not like these magazines only have one go at getting it right. Unless they are testing all times on a dragstrip where traction is a sure thing and almost all of the available power can be put down in first gear then times should be more consistent than they are against European mags. I know given 6~10 goes at it I could get the same M3 to produce times within a tenth or two of each other, but 1.2s is more than a slight variation, it's huge.

I still maintain that press cars are better than stock but up to 10%, ie. press car M3 may have 440hp but stock M3 might vary from 420hp down to as low as 400hp.

[bruce.augenstein@comcast.]

Originally Posted by footie

Bruce,

There is an optimum way of getting a rwd car off the line and it's not like these magazines only have one go at getting it right. Unless they are testing all times on a dragstrip where traction is a sure thing and almost all of the available power can be put down in first gear then times should be more consistent than they are against European mags. I know given 6~10 goes at it I could get the same M3 to produce times within a tenth or two of each other, but 1.2s is more than a slight variation, it's huge.

footie, I'm not sure I made myself clear. I'm not talking about effectiveness in an acceleration test. I'm talking about test methods. As a for instance, Car & Driver lets the car roll a foot before they start the clocks, which is in the vicinity of four or five tenths of a second for the average street vehicle of the kind we're fond of. They also adjust their results for varying weather condiditons. Other entities do other things. As far as I know, Consumer Reports starts at idle and the clocks begin ticking as soon as the vehicle beginns to roll. That's probably close to a second right there, same car, same day.

If you take these things into consideration, plus car to car variation, a variation in 0 - 100 times from 9.4 to 10.6 seconds isn't even worth talking about.

Bruce

Originally Posted by footie

I still maintain that press cars are better than stock but up to 10%, ie. press car M3 may have 440hp but stock M3 might vary from 420hp down to as low as 400hp.

I think the M guys may grab an engine that tests near the top of the class and that sort of thing, or maybe just check out a given car very carefully to make sure it's in the peak of health, but probably don't bother going any further. Some of the magazines even test emissions from time to time, to keep everybody honest.

Bruce

[Keto]

Originally Posted by bruce.augenstein@comcast.

You are inadvertently discussing two different things here.

Bruce

Not so inadvertently, although my intent may not have been clear. I mentioned the official times because BMW clearly does not set the bar that high as far as the press releases go -- the magazines do that for them later. Nissan, on the other hand, released this car after telling everyone they were testing it against the 911tt and beating it, except now at the very least we know you may not get a car that beats a 911tt.

You and I are making the same point about comparisons of timed events that depend on several variables vs comparisons of HP. Admittedly, the HP comparison we are discussing from the original article (and others) involves a derivation from trap speed.

I will break my concern down simply:

Is the variation in HP ratings for the GT-R larger than normal? If so, is the variation in HP ratings due to "standard" car-to-car variability, lax engineering tolerances or "ringers?"

[footie]

Originally Posted by bruce.augenstein@comcast.

footie, I'm not sure I made myself clear. I'm not talking about effectiveness in an acceleration test. I'm talking about test methods. As a for instance, Car & Driver lets the car roll a foot before they start the clocks, which is in the vicinity of four or five tenths of a second for the average street vehicle of the kind we're fond of. They also adjust their results for varying weather condiditons. Other entities do other things. As far as I know, Consumer Reports starts at idle and the clocks begin ticking as soon as the vehicle beginns to roll. That's probably close to a second right there, same car, same day.

If you take these things into consideration, plus car to car variation, a variation in 0 - 100 times from 9.4 to 10.6 seconds isn't even worth talking about.

Bruce

Now I understand why there is such a difference, as someone from Europe I don't get to read or am familiar with some of the US magazine test procedures. I can't understand how they can call this 0-60mph when the car isn't at a complete stop.

You are totally correct in saying it will account for a minimum of 0.5s just there on it's own.

Originally Posted by bruce.augenstein@comcast.

I think the M guys may grab an engine that tests near the top of the class and that sort of thing, or maybe just check out a given car very carefully to make sure it's in the peak of health, but probably don't bother going any further. Some of the magazines even test emissions from time to time, to keep everybody honest.

Bruce

I won't say how I know that manufacturers do improve their press cars but I can assure you that it is common practise.

[lucid]

Originally Posted by footie

You say the emission will be off, that's correct but then tell me a magazine that checks this out on a road test. The only way round the possibility of ringers is for magazine to dyno the cars tested, such a thing would let people see the true figures these press cars are putting out.

But how exactly? What are you saying, that they use different engine internals on press cars? Can you be more specific? What would they be doing differently? I say no way they will stick in different hardware and build the engine differently. That would be a huge blow if the modifications were to be discovered somehow. Again the most they can do is to play around with the software, and I doubt that they would do that either. Even if they did, that won't give you 40 hp for the NA M3 engine, which is 10% more power, which is what you are claiming. They might cherry pick cars coming out of the factory, but again that won't result in 10% variation.

[footie]

Tell me, how much difference could lightened internal possibly make to the overall performance, then slight tweaks to the software.

This is only a hypothetical question mind.

[lucid]

Originally Posted by footie

Tell me, how much difference could lightened internal possibly make to the overall performance, then slight tweaks to the software.

This is only a hypothetical question mind.

If they are using different pistons, rods, shafts and all that in press car engines, that would be a major cheat. Yes, a journalist can simply open the trunk and see that, but they might start asking questions after they've driven a production car when they feel the difference. And I think one can feel the difference in increased response and the additional 40 hp. At least some of them should be able to. Then there is the issue of people eventually "talking". Those guys in the factory who put the engines together might start telling stories after they retire or leave the job. I am not saying it is not impossible, but it would be extremely risky IMO. Not worth risking your brand image over...

[footie]

Originally Posted by lucid

Those guys in the factory who put the engines together might start telling stories after they retire or leave the job.

It was something I heard a few years ago but I will not elaborate any more than that.

[bruce.augenstein@comcast.]

Originally Posted by footie

Now I understand why there is such a difference, as someone from Europe I don't get to read or am familiar with some of the US magazine test procedures. I can't understand how they can call this 0-60mph when the car isn't at a complete stop...

They do the one foot "rollout" (as it's called) to zero their timing to dragstrip clocks, which don't start until your front tire has rolled out of the "staging beam". Drag strips are very popular in the States.

Rollout for an average street tire is about a foot, hence the test procedure to mimic that.

Bruce

[lucid]

Originally Posted by footie

It was something I heard a few years ago but I will not elaborate any more than that.

But Footie, stories cut both ways; they are often bogus!

[footie]

Originally Posted by lucid

But Footie, stories cut both ways; they are often bogus!

I know but somehow I believe this guy. Especially as he still works there and is not your production fitter if you know what I mean.

[footie]

Originally Posted by bruce.augenstein@comcast.

They do the one foot "rollout" (as it's called) to zero their timing to dragstrip clocks, which don't start until your front tire has rolled out of the "staging beam". Drag strips are very popular in the States.

Rollout for an average street tire is about a foot, hence the test procedure to mimic that.

Bruce

Thanks for the explanation, it must be a case that in the States drag racing, even in your normal car is a big thing.

This may also explain why the 1/4 mile times in the US are better as well.

[sayemthree]

car and driver got 0-60 in 4.1 and 100 mph in over 10 secoonds for the GTR vs the 911, z06 and viper. it won the test - but I recall the M3 has matched this 60 time and beaten this 100 time.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

As a for instance, Car & Driver lets the car roll a foot before they start the clocks, which is in the vicinity of four or five tenths of a second for the average street vehicle of the kind we're fond of.

Bruce, I was curious about the number of tenths you mention here. Doing some simulations for the 6MT M3 in CarTest and varying the one foot value down to exactly 0 feet indeed produces results 0.4 seconds difference (of course across the board) for all 0 to speed X times.

[gbb357]

Swamp, not to start anything, but why aren't you complaining about this post and complained about the ZR1 Ring Time post? Just curious, not looking to start an argument.

[armyav8tor]

End the speculations. Someone will dyno the GTR sooner or later.

[sayemthree]

Originally Posted by swamp2

Bruce, I was curious about the number of tenths you mention here. Doing some simulations for the 6MT M3 in CarTest and varying the one foot value down to exactly 0 feet indeed produces results 0.4 seconds difference (of course across the board) for all 0 to speed X times.

I call BS. then they should call it 2-60. not 0-60. most mags that do a 5-60 rolling start get slower times. most of them use GPS units now and I doubt they cheat, which is exactly what this would be.

In any case if they do cheat then they cheat equally for all cars?

[swamp2]

Originally Posted by sayemthree

I call BS. then they should call it 2-60. not 0-60. most mags that do a 5-60 rolling start get slower times. most of them use GPS units now and I doubt they cheat, which is exactly what this would be.

In any case if they do cheat then they cheat equally for all cars?

Closer to 4-60 for an M3.

Of course they offer consistency, all cars are tested in the exact same way and have been for some time.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Bruce, I was curious about the number of tenths you mention here. Doing some simulations for the 6MT M3 in CarTest and varying the one foot value down to exactly 0 feet indeed produces results 0.4 seconds difference (of course across the board) for all 0 to speed X times.

Going back to paleolithic times, I learned through observation, trial and error that with half-second intervals between lights on the drag strip "christmas tree", you could launch on the last yellow instead of on the green. That would give you about five car lengths on the street racer in the next lane at the finish line (at the 100-102 mph trap speeds common to my GTO and other muscle cars of the time).

Subsequent curiosity led me to do the basic analysis, including street tire coefficients of friction and weight distribution (plus weight shift), thus arriving at approximate max G. Since theoretical max G could be attained by virtually any muscle car at launch (or nearly any car, for that matter), basic arithmetic then could confirm what I had observed.

Anecdotally, when facing a very tough opponent in my class at the track, I'd often line up "crooked", facing perhaps five degrees right at launch. This would lengthen my potential rollout by about five inches or so, allowing me to launch even a bit before the last amber began to think about warming the filaments, giving me the win even with a slower ET. Doing the arithmetic shows you don't get much out of those additional inches, but enough.

You'd think the additional rollout would also improve ET, but I found that the side loads generated by straightening the car out (no matter how quickly or slowly you did it) negated that advantage.

I used to routinely say a half second, but now say four to five tenths because of the improved traction of today's sporty rubber, plus less time loss due to tire windup because of shorter and stiffer sidewalls compared to cars in the '60s.

Bruce

[bruce.augenstein@comcast.]

Originally Posted by sayemthree

I call BS. then they should call it 2-60. not 0-60. most mags that do a 5-60 rolling start get slower times. most of them use GPS units now and I doubt they cheat, which is exactly what this would be.

In any case if they do cheat then they cheat equally for all cars?

Do drag strips cheat as well? As already explained, the magazines do this to zero their times to the drag strip. Of course 5-60 times will always be slower, because you no longer have rollout, plus you're not using rotating inertia (or torque converter preload) to your advantage.

Bruce

[BMW-videos.com]

Originally Posted by bruce.augenstein@comcast.

Going back to paleolithic times, I learned through observation, trial and error that with half-second intervals between lights on the drag strip "christmas tree", you could launch on the last yellow instead of on the green. That would give you about five car lengths on the street racer in the next lane at the finish line (at the 100-102 mph trap speeds common to my GTO and other muscle cars of the time).

Subsequent curiosity led me to do the basic analysis, including street tire coefficients of friction and weight distribution (plus weight shift), thus arriving at approximate max G. Since theoretical max G could be attained by virtually any muscle car at launch (or nearly any car, for that matter), basic arithmetic then could confirm what I had observed.

Anecdotally, when facing a very tough opponent in my class at the track, I'd often line up "crooked", facing perhaps five degrees right at launch. This would lengthen my potential rollout by about five inches or so, allowing me to launch even a bit before the last amber began to think about warming the filaments, giving me the win even with a slower ET. Doing the arithmetic shows you don't get much out of those additional inches, but enough.

You'd think the additional rollout would also improve ET, but I found that the side loads generated by straightening the car out (no matter how quickly or slowly you did it) negated that advantage.

I used to routinely say a half second, but now say four to five tenths because of the improved traction of today's sporty rubber, plus less time loss due to tire windup because of shorter and stiffer sidewalls compared to cars in the '60s.

Bruce

clever, very clever

[BMW335icDDS]

Haha nice read.