GTR beats 911TT and Z06: from Road&Track

[bruce.augenstein@comcast.]

Originally Posted by swamp2

If the SC package delivers more torque over that broad of an rpm range the hp must increase in about the same ratio. Have you seen a dyno run for the SC package. Could it be that the torque is onlydelivered so low in rpm that the peak hp is not affected much?

What I have been told by a 997 Turbo owner is that the full overboost is available between 2100 and 4000 rpm, and then tapers off gradually until it's at "normal" boost by the time you get to the power peak, which is therefore unchanged. He said it's most apparent in first and second gears, but that even in third and fourth, it's there after the shift.

On the other hand, I've just read devo's post, and in addition to being authoritative, it makes complete sense to me.

If devo is completely correct, then in my opinion the overboost isn't available for long enough during a quarter mile run to materially affect the trap speed. In that case, its augmented power (estimated from quarter mile speed) is from something else entirely.

Bruce

[devo]

Originally Posted by bruce.augenstein@comcast.

What I have been told by a 997 Turbo owner is that the full overboost is available between 2100 and 4000 rpm, and then tapers off gradually until it's at "normal" boost by the time you get to the power peak, which is therefore unchanged. He said it's most apparent in first and second gears, but that even in third and fourth, it's there after the shift.

On the other hand, I've just read devo's post, and in addition to being authoritative, it makes complete sense to me.

If devo is completely correct, then in my opinion the overboost isn't available for long enough during a quarter mile run to materially affect the trap speed. In that case, its augmented power (estimated from quarter mile speed) is from something else entirely.

Bruce

I did not realize that I was being authoritative. But... okay.

I did own a 997tt (althoguh owninga car does not necessarily make my opinion(s) correct) and have seen dyno sheets that confirm much of what I have said; specifically where boost tapers at 4k then returns to normal at 5k. As I said, over-boost would only be realized in first gear during any drag race.

[bruce.augenstein@comcast.]

Originally Posted by devo

I did not realize that I was being authoritative. But... okay...

My Webster's says: "having the weight of authority; official"

My intent was to use a slightly more powerful word than, say, "credible".

In other words, it seemed to me that I ought to lend weight to that particular post.

Bruce

[swamp2]

Originally Posted by bruce.augenstein@comcast.

...
Using the more than 50 year old (and basic) formula of trap speed divided by the constant 234, result cubed, times the tested weight gives the following:
...

Bruce, using the recent C&D numbers that gbb posted and your formula above puts the GT-R right back at 580 hp. Trap was 124, weight 3908. Not sure this formula is so "tried and true" and if so we are right back to the under-rating issue.

[footie]

Originally Posted by swamp2

Bruce, using the recent C&D numbers that gbb posted and your formula above puts the GT-R right back at 580 hp. Trap was 124, weight 3908. Not sure this formula is so "tried and true" and if so we are right back to the under-rating issue.

Pick the one you feel that suits this thread.

[gbb357]

Originally Posted by footie

Pick the one you feel that suits this thread.

^^^^

[swamp2]

Look guys, glad you feel it is all hilarious and pathetic. I am genuinely interested in the various conundrums here. If you will recall I have faced near infinite flak from Bruce about the validity and application of formulae (which really is what simulation is anyway - a whole lot of forumlae). I am very curious how he can explain this. Tell me a 124 mph trap speed does not give you slightest inkling, of a small possibilty, of a slight over-rating?

[footie]

The thing I find hilarious is the fact that we has all written posts on the GTR, possibly hundreds by now and yet we are right back to the original comment from your good self swampie that the GTR is Under-rated after all.

[swamp2]

Originally Posted by footie

The thing I find hilarious is the fact that we has all written posts on the GTR, possibly hundreds by now and yet we are right back to the original comment from your good self swampie that the GTR is Under-rated after all.

Well it is funny I guess. But the evidence just won't seem to cooperate (to put it very sarcastically) with the specs. I am certainly not going back down the path of "massive under-rating" but I think something is very much in question with Bruce's magic formula, the cars hp or both.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Look guys, glad you feel it is all hilarious and pathetic. I am genuinely interested in the various conundrums here. If you will recall I have faced near infinite flak from Bruce about the validity and application of formulae (which really is what simulation is anyway - a whole lot of forumlae).

C'mon, Swamp, you have to admit this is funny - and by the way, the remarks and general reactions are not all at your expense.

By the way, you never got any flak from me about the validity and application of simulation tools/formulae. Nope, it was more personal than that. It was specifically about your use of those tools, and you have to admit that at first, you were pretty pathetic.

Originally Posted by swamp2

I am very curious how he can explain this. Tell me a 124 mph trap speed does not give you slightest inkling, of a small possibilty, of a slight over-rating?

My explanation is that if the numbers hold up (and in my opinion, C & D doesn't screw up very often), then the GT-R is massively under-rated, or at least their particular Amerispec test car was. No smiley. I'm not kidding.

The speed over 234, result cubed times vehicle weight formula really is tried and true, and the last time I saw it was in the April Road & Track as part of an answer in the tech questions section - page 106.

That formula shows the GT-R with over 600 HP, assuming 124 mph and 4078 pounds with full tank plus driver and test equipment (3908 curb weight).

Horsepower understated by more than 20%? Is that massive? I should say so! If these results start coming in from other sources, it'll be confirmed, in my book.

I may need to face in your compass direction from my place and do the "We're not worthy!" bow at least three or four times.

On the other hand, there's something a little screwy about the disparity between Road & Track and Car & Driver. They vary a bit in test methods, most notably in that R & T doesn't bother zeroing their results to standard day test conditions, but in this case test conditions were quite good at their site. So, 124 mph vs 116.5 mph just isn't a credible difference unless we've got either a problem with one car or a ringer for the other.

Film at 11, as they (used to) say. Meanwhile this situation grows curiouser and curiouser. I am definitely looking forward to the inevitable further comparison tests.

Swamp, if we see more of such trap speeds from the GT-R, you were right, right from the beginning.

Bruce

PS - Of course, you really were an "Abbott and Costello in the lab" routine with your early simulations.

[footie]

Bruce,

When you compare the M3 results in Europe against those in the US and in particular C & D you have to assume that almost all of their results must come from ringers.

[swamp2]

Originally Posted by bruce.augenstein@comcast.

C'mon, Swamp, you have to admit this is funny - and by the way, the remarks and general reactions are not all at your expense.
...

Good that you are open to the evidence and all of it. This has been my primary thrust all along. This 124 mph thing is pretty darn clear evidence. I did not sweat the details between curb/as tested figures so just used their 39XX lb figure and this rough formula to come up with the ~580 hp number.

As much as you are willing to pass along a couple of small compliments here your ongoing insults and exaggerations are have worn thin long long ago. Do we have to completely address all of these old topics? Your insults push me to want to do so. My early attempts "pathetic", sure a couple mph and a couple tenths here or there = pathetic. We will never see eye to eye on the sources and real meaning of simple concepts like average, standard deviation, systematic and random errors. What about your use of a 2WD simulation tool to simulate an AWD vehicle, talk about, inapproproate and hopelessly inaccurate. Note my avoidance of much more insulting words/terms like pathetic or "Abbott and Costello".

Pot, kettle, black.

Carry on, and like I always say let the evidence continue to flow and to be analyzed.

[swamp2]

Originally Posted by footie

Bruce,

When you compare the M3 results in Europe against those in the US and in particular C & D you have to assume that almost all of their results must come from ringers.

Not so. A 111 mph to 115 mph variation in trap is not quite as extreme as 124 vs. 117. You can not just subtract the numbers, i.e. max spread = 4 vs. 7. There is a CUBIC relationship here as well as a much larger spread. Rememer that tests absolutely are not always appled to apples, in fact we know them to generally be apples vs. organges.

[footie]

Originally Posted by swamp2

Not so. A 111 mph to 115 mph variation in trap is not quite as extreme as 124 vs. 117. You can not just subtract the numbers, i.e. max spread = 4 vs. 7. There is a CUBIC relationship here as well as a much larger spread. Rememer that tests absolutely are not always appled to apples, in fact we know them to generally be apples vs. organges.

Fair play but why is there so little a difference on this side of the water. Could it be possible that manufacturers spice up their cars in the US because it's so large a market to them.

Look at the figures for the GTR on this side of the water and I reckon they will be closer to that of the 117mph figure.

[bruce.augenstein@comcast.]

Originally Posted by swamp2

Good that you are open the the evidence and all of it. This has been my primary thrust all along. This 124 mph thing is pretty darn clear evidence. I did not sweat the details between curb/as tested figures so just used their 39XX lb figure and this rough formula to come up with the ~580 hp number.

As much as you are willing to pass along a couple of small compliments here your ongoing insults and exaggerations are have worn thin long long ago. Do we have to completely address all of these old topics? Your insults push me to want to do so. My early attempts "pathetic", sure a couple mph and a couple tenths here or there = pathetic. We will never see eye to eye on the sources and real meaning of simple concepts like average, standard deviation, systematic and random errors. What about your use of a 2WD simulation tool to simulate an AWD vehicle, talk about, inapproproate and hopelessly inaccurate. Note my avoidance of much more insulting words/terms like pathetic or "Abbott and Costello".

Pot, kettle, black.

Carry on, and like I always say let the evidence continue to flow and to be analyzed.

One of the reasons you're my favorite pain in the ass is that you're so damned easy.

Meanwhile, this is pretty fascinating stuff. The only thing that sort of jumps out is that the C & D car was an engineering test mule, which could mean anything - or nothing, of course.

Bruce