GT-R: full test (with dyno)

Discussion in 'Asian Forums' started by mafalda, Sep 15, 2009.

  1. #101 906, Mar 1, 2010
    Last edited by a moderator: Apr 25, 2016

    Stock GT-R R35
  2. #102 906, Mar 1, 2010
    Last edited by a moderator: Apr 25, 2016

  3. #103 F40 Le Mans, Mar 1, 2010
    Last edited by a moderator: Apr 25, 2016
    WTF. These cars are really POWERFUL.
    These GTRs are all customers cars,
    we started this post talking about 468.1 hp achived by a HyperPower dyno during the
    SoCal GT-R Dyno Day ending about 517.8 hp for the DM Performance result.
    That's amazing for the top toleraces, looking the production of these engines.
    I think there are bit climatic condition differences during the runs, and MY08 to MY10 development, but a 10.6% differences
    also in the results.
    From months, some European magazines are aware about the excessive kindness and generosity of these engines. Not for this point others mags.
    Comportment of these cars is so incredible at the facts.

    545 hp for the 911 Turbo MKII is incredible too. A big jump from the 1st model. Seen 470-480 hp region dynos about this car.
  4. God I love the GT-R.
  5. #105 F40 Le Mans, Mar 2, 2010
    Last edited by a moderator: Apr 25, 2016
    Since the introduction of the GT-R, Nissan has stated a horsepower rating of 480. However, that number actually refers to the Japanese-spec GT-R certified at 480 PS, which converts to 473 SAE horsepower. Apparently Nissan prefers nice, round numbers, and are aiming to bring the U.S.-spec GT-R up to 480 hp by the time it hits dealerships in June. Either that, or they just want to make sure its specs are on par with the Porsche 911 Turbo, which was used as a benchmark in the car's development. We doubt anyone would love the GT-R less without that seven extra horsepower, but we're not about to complain. No word yet on what changes will be made or how it will be achieved.
    Here is a subject that sounds complicated. Don't worry Its not! You look at your dynamometer print out and see that CF 0.9081 or CF 1.0973 number on your ! And its very important!
    Basically what we want a dynamometer to do is give us the same result (say 100bhp) on the same engine every time we dynamometer test it! Because if you go away, fit some different parts, change jets, or whatever you want to compare the new result at a later time right? Otherwise the figures are useless!
    Well here is the problem... You shove your you car / bike on the dynamometer Monday night... Its cool, say 10 degrees Centigrade. You do a run and it measures 100 BHP! Great!
    Now you go away and do NOTHING to your car and return on Tuesday in the middle of the day. Its 25 degrees C and a lovely warm day! You now re dyno test your car, and guess what, It makes only 94 BHP. Is it broke? No! Its just breathing in warmer air which is less dense! So we need a formula that looks at the air temperature that your engine is breathing in and "CORRECTS" the power figures to a known standard temperature. Easy. Now, using this correction factor, whatever the air temperature your engine will always read the same 100 BHP.
    But there is another small problem... On some days there is a also a "higher" or "lower" atmospheric pressure too! (Look at your barometer) So when the pressure is "high" your engine will make more power so the dyno shows your 100 BHP engine is now 104 BHP... So we now need another formula that corrects the measured power for atmospheric pressure variations too! So we use another "correction" so that your engine will now read 100 BHP regardless of both air temperature, or atmospheric pressures.
    In addition Humidity makes a "very small" difference too! But this is usually ignored by most manufacturers. So we will too. It is worth mentioning though that humid air actually costs power, rather than the common belief that it helps! It doesn't. It replaces part of the air/oxygen in the atmosphere.
    So provided that our new formulas (now lumped together and called correction factors) works as it should we should be able to read the same 100 BHP from our Corrected Dynamometer figures under all conditions. This means you can directly compare figures on different days and conditions & locations. (the pressure at the sea is much higher than if you live in the mountains!)
    So your car will read 100BHP at the top of a high mountain, on a hot day when the pressure is low, as it would at sea level in winter on a high pressure day! At least that's the plan!
    This pressure and temperature data has to be measured, and entered as figures, or sensed automatically depending on which dynamometer system we are using directly just before each "run" is made. If this is not done the data or graph will not be accurate!
    Now this is the bit that's confusing people. It had to come!
    There is more than one correction factor! None are perfect. All are a simplistic compromise. But its the best we have! In my own software, I have a choice of four different ones that are commonly used, and uncorrected for raw data or electric vehicles:
    SAE-J1349 the one that seems to work best! And is used by lots of dyno companies as default.
    DIN 70020 Also popular, and used by people who like bigger numbers! In a lot of conditions it gives figures a few percent higher than the rest.
    EEC 80/1269
    ISO 1585
    If you choose a run and display a power curve in my own dyno software you can choose from these 5 options to see how it effects the measured power. They are all different, but all are correct! This is where a lot of the "disagreements" about power figures arise!
    See its not "that" painful!
    The most common are the SAE standards. The older J607 standard considers that the engine was run on a 60°F day with 0% humidity and a barometric pressure of 29.92 in-Hg or the newer SAE J1349 standard of 77°F (25°C) day with 0% humidity and a barometric pressure of 29.234 in-Hg (99 KPa). Also the ECE standard is the same as the SAE J1349, but does not use mechanical efficiency in the calculations. The DIN standard which corrects to 68°F (20° C) day with 0% humidity and a barometric pressure of 29.92 in-Hg (101.3 KPa) and the JIS standard corrects 77°F (25° C) day with 0% humidity and a barometric pressure of 29.234 in-Hg (99 KPa), but uses different correction curves than the others (as a substitution for using mechanical efficiency factors). Further, we have the J1995 corrects 77°F (25° C) day with 0% humidity and a barometric pressure of 29.53 in-Hg (100 KPa).

    Here in Europe we use the DIN-certified. So there are bit differences beetween dynos. Our are higher figures.
    EWG 80/1269 corrected (25°C - 0% humidity - 99KPa) is like SAE-corrected and not as DIN-corrected.
    Auto magazine has tested using the EWG 80/1269 correction, it run in 34°C air aspired with 55% humidity and 977 hPa of barometric pressure. 489HP SAE achived seems 17hp more power with the same correction and power unit of 473 hp SAE horsepower declared.
  6. ^That post describes why it is next to useless to compare dyno numbers from different sources. Dyno'ing on rollers vs an engine dyno further clouds the issue.

    "489HP SAE achived seems 17hp more power with the same correction and power unit of 473 hp SAE horsepower declared."
    473 hp SAE is the old US rating. The current advertised rating is 485 hp SAE. Even if we accept the 17 hp discrepancy, that's only 3.4% difference and well within manufacturing tolerances.

  7. Right.
    Here you have an other SAE/ECE corrected dyno of a stock GT-R.
    It's quoted 465 PS SAE/ECE and it describes the possibility of a 5% power tolerance beetween engine and engine. All engines within manufacturing tolerances. Is very interesting a look about how are able the two engines at vary of the two different climatic conditions in comparison of the SAE reference. And DIN, how it increase looking the similar DIN conditions. <A BORDER="0" HREF=""><IMG BORDER="0" SRC="pitlane/emoticons/smile.gif"></A>
  8. Here is the problem with just about any dyno result for a turbocharged engine that has been corrected to the SAE or DIN standards. SAE J1349, Section 5.5: "... boosted engines with absolute pressure controls shall not be corrected for ambient barometric pressure."

    If the Euro tests are factoring in the higher temperatures and different pressures and humidity, then they are correcting UP on a turbocharged engine which is already making the correction. Therefore, they are reading high.
  9. These two dynoed GTRs are able of 480 DIN and 500+ DIN figures. Even better figures during better conditions days. I think the record was achieved during a long session of tests, during the years, in best condition days, and we are even talking about mule cars.
    I still found stupid to consider 7.26 possible for any "480" performance car, quoted for 480 DIN. Anyway...

    I give you an example: the F40s are quoted 1.29.6 in the list of Fiorano lap times. They are included all the F40s, standard and cats cars. But some standard F40s was able of 1.27 drived by Dario Benuzzi in the first morning of some days during the year. These days were better for the track performances, even the tires and the engine performance. The F40 was quoted 478CV DIN but is really able of 515 HP. There are F40s 517 bhp dynoed uncorrected. So, the engine power could be "a" point for the best performance. But, they are quoted "1.29.6" only for the productions.

    Come back for the GT-R. VDC effects are important, but "when" and "where" and "for wich GT-R" is important too. Searching the record
    a fast GT-R is surely better than a weak car, even with all the good effects of any type of electronic systems.
    Looking F40s times at Fiorano during the year and the production, the GT-R could swing 15 or 20 seconds well behind the car producted and the climatic conditions with the same effort during the year. In Nissan, they aimed at the top. Opinions? Yes.
    I like the GT-R but still stupid a time for extreme best time in a world of standard limit numbers.

    "Therefore, they are reading high"
    Or, they are uncorrected, and they are referring about better climatic conditions than the SAE/ECE or DIN standards <A BORDER="0" HREF=""><IMG BORDER="0" SRC="pitlane/emoticons/smile.gif"></A>
  10. Wait, you said:
    "Auto magazine has tested using the EWG 80/1269 correction" meaning they have applied the correction and that is the result you see printed in the magazine. There is no point to even mention this if they don't print the corrected figures.

    As for your other data, it seems that you are finally getting the point. Nissan didn't have to cheat with getting the ideal conditions; they tested there so extensively that sooner or later they were bound to find them. They never hid this fact. The world media were watching them closely, taking hundreds of photos (none of which show the GT-R on slicks, interestingly). The real stupidity falls on those who b1tched and moaned about the times while ignoring the fact that the 'Ring can vary from one lap to the next. This is a fundamental error in understanding context.
    Even if the GT-R made 600 hp, its time of 7:26 still doesn't make any sense given its weight. Not even Sport Auto's 7:38 makes any sense. So to continue to cling to PEAK hp/wt as if this singular statistic (which occurs at infinitesimally small periods anyway) overrules all other factors is to ignore the true meaning of physics as it relates to lap times, not to mention the wealth of data the world over showing the GT-R (even green customer cars) is as fast or faster than cars with better power/wt ratios. The simple fact is, the GT-R's AWD, grippy tires, long wheelbase, DCT, and resistance to being knocked off course by bumps (no doubt aided by its considerable mass) means it can put down MORE of its peak hp/wt MORE of the time.
  11. "There is no point to even mention this if they don't print the corrected figures"
    It was mentioned next to the dyno, in the same page.
    *vedi grafico, di 462,3 cv a 6000 giri, che con il fattore di correzione ambientale a norme EU diventano 489,6 reali*

    Anyway conditions during the year had their importance. Looking the dynos above, at the vary of conditions even the engine has their increments or losses.
    In the 2nd dyno GTRs engine increment about 14hp (and torque) from SAE (25 °C, 0% humidity, 990hPa) to 20 °C, 26.8% and 1014.
    That's incredible thinking about a strong engine in even better conditions.
    I agree all the other points about the dynamics caratteristics of GTR and the effort of the Nissan group about testing for long time even every type of vary conditions.
  12. Take a look at this point about better condition about this 996 GT2 engine.
    Is quoted 487HP but is able of 500HP in better conditions than the SAE standard.
    A 489HP SAE GT-R develop 462 hp in a 30°C day when a 487HP SAE 996GT2 is able of 500HP in a 14°C day.
    A GT-R or a GT2 could swing for over 40HP from a hot summer day to a better spring day. And that could be not the widest range of reference during the year.
  13. "vedi grafico, di 462,3 cv a 6000 giri, che con il fattore di correzione ambientale a norme EU diventano 489,6 reali"
    "See chart of 462.3 hp at 6000 rpm, and with the correction factor EU environmental standards become real 489.6"

    That means *with* the correction factor. A correction factor that SAE says should not be applied to turbocharged engines since they can control the intake pressure in a way that a naturally aspirated engine can't.
    This means the real, uncorrected dyno figure on this GT-R was probably LESS than 489.6. Based on the conditions listed, the SAE correction factor should be about 1.01913866, which means the uncorrected raw figure was about 480 hp. That's a far cry from 530 hp.

    The dyno chart you posted shows 500 PS, which is 493 hp. Not too different from the claim of 487 hp. Without knowing what that particular GT2 dynos on a hot day, you couldn't claim a swing of 40 hp with any reliable accuracy. The benefit of forced induction is that it avoids the wild swings in hp as a function of atmosperic pressures.
  14. Could be. Anyway we must take good it for EU certificate being in Europe, and a dyno certificated EU, I think, verify “its” correction as well.
    We must also not compared it with any naturally aspirated engine. Only know as this engine is.

    As for the 996GT2 the dyno shows 500PS for engine power compared to corrected 487PS for “PS” when is claimed for 483PS by the factory.
    My swing accuracy only is an esteem as you see. Dynos shown sometimes significant differences compared to EU standards at the vary of conditions, even with the forced induction, and 500PS are verified only in a 999hPa day.
  15. Could be? It says right in the part which you quoted that 489.6 PS is with the correction.

    13 PS on the Porsche is only 2.7% more than quoted and is well within manufacturing tolerances. We cannot pin this down on either factor (conditions vs tolerances); it could be a little bit of both. Hell, the same car, dynoing only minutes apart and with zero modifications can see differences of 5 hp. The dyno is useful for tuning and comparing modifications on the same exact car; manufacturing tolerances between cars skews the data further. As such, it's no foolproof way to confirm or disprove manufacturers' hp claims.
  16. #116 F40 Le Mans, Mar 5, 2010
    Last edited by a moderator: Apr 25, 2016
    •Projection of engine power according to DIN 70020, EEC 80/1269,ISO 1585,JIS D 1001,SAE J 1349
    •Determination of data according to vehicle type
    So, you are tell me that Maha dynos with all their tecnologies being according with all the standard certificates plus the possibility to determine the data according to vehicle type over all the others functions, they are not able to *exclude* function about the pressure for turbo engines? Maha are very accurate dynos and than they are #$%#ed for a "double reading pressure"? If the test procedure of correction was corrected, is corrected even the result.

    About Porsche dyno, I'm not "pin" nothing. I'm only saying the possibility of well over 500PS if this car will be dynoed in favourable pressure conditions that 999hPa for its engine. Or, better day condition.
  17. worst thread
  18. #118 Guibo, Mar 5, 2010
    Last edited by a moderator: Apr 25, 2016
    They can *exclude* the correction factor if they want. It's up to the dyno operator. Users can apply whatever correction factor they want, or none at all. The fact is, your article states they applied a correction factor when the SAE standard says one should not correct for atmospheric conditions, and even when they did, it was only 4.6 hp more than the factory claim. Unadjusted for conditions, it was likely a neglible 5 hp less than the factory claim. Yet it still put up acceleration figures comparable to Sport Auto's car, which lapped in 7:38 after only 3 timed, flying laps, with VDC-R on, by someone who sure as hell didn't have thousands of laps in the thing.
    Your rambling ignores the fact that the hp figure is so far off the 530-560 hp theories anyway.
  19. Now, if they *can* apply whatever correction factor they want, wich is "bouble reading pressure" the problem? <A BORDER="0" HREF=""><IMG BORDER="0" SRC="pitlane/emoticons/smile.gif"></A> I hope was not a preconception or other problem, anyway "Auto" workers are very competent people, and surely they were in the view of the real power of their car.

    I'm not trying to say any 530-560 HP theories, a SAE 490HP GT-R is FAR. I'm ONLY saying how is the difference testing in two very different conditions, even about the engine result. (Looking even the F40 at Fiorano during the year). A GT-R like that Auto tested, being with-in the factory tolerance, it could be able of something about 500-510HP range if the condition of temperature, humidity and pressure are able of it, "being even" in the SAE or EU tolerace. I'm not saying Nissan is cheating or something. I think a record so good could be achieved for that in "a part" of all the GT-R performances, being tested for long time in many test sessions. Or still all a preconception? I hope not, least once.
    IMO this time should not be compared with the other cars. Or comparable only with the same procedures.
    Neither Porsche apply the same "lap times procedure".. the 7.3x of W.Rohrl seems to be cracked many times by other Porsche official drivers not even using the same procedures of Nissan, nevertheless they have not replaced the official time. Even with the 911Turbo Mk1 they are still using a not greedy time of 7.49 of W.Rohrl when HvS did 7.54 only. So how are comparable with Nissan "procedure"?
    Nissan, has gambled on, smart, especially to hit the customer or the passionate, to talk about their car, I approve it, but they put their exceptional time "among" times made with other procedures.
    Is much more important for me knows that a driver like HvS was able of 7.38 during its 2nd session in the GT-R, than the 7.26 of Suzuki.
    First, because is a better yardstick about the GT-R project and compared it with the 911 level.
    Than, that Suzuki is able of 7.26 when W.Rohrl only 7.49 are only words because probably one is an extreme limit and the second could be further improved by some seconds-STOP

    PS. you said me I'm a IDIOT. I remember this. About different "procedure" IDIOTs are who want compare its dick UP when the others are down. And the fanboys of that theories. Not who want really know the truth and compared it with the same yardstick procedure.
  20. Yes, people who consider the lap times without context ARE idiots. You were saying before as to how Nissan might have cheated (on the basis of hp/wt) with 530-hp engines, ignoring the huge role of conditions, and now you are revising your hp estimate to a lower level. Haha. Well, maybe on a good day, it might be capable of 510 hp on a warm-up lap. Maybe after the warmup lap and with heat soak, it might produce only the claimed 485 hp. How the hell are you ever going to account for this? You can't. And if you can't, then just STFU about hp discrepancies because you can say that for just about ANY manufacturer's car. On a good day, another manufacturer's car might make more hp than the claimed SAE net figure too!
    Even at 600 hp, the GT-R's lap time STILL DOESN'T MAKE SENSE. (Well, maybe to some non-Interweb physicists, it makes perfect sense.)

    "Even with the 911Turbo Mk1 they are still using a not greedy time of 7.49 of W.Rohrl when HvS did 7.54 only."
    Nope, they still stand by the 7:38 that their Turbo did with the MPSC's. Rohrl's time is considered without the optional performance tire. The fact of the matter is, the GT-R has taken on the Mk1 Turbo many times on numerous head-to-head comparisons and has thoroughly beaten it. Even the Mk2 Turbo has trouble beating the GT-R; we have seen in the Autocar test that the updated Turbo still nods vigorously over bumps, a by-product of its inherent weight balance issues. And the 'Ring is full of bumps...
    HvS drove the GT-R a second time, but his first time was not a 10/10ths effort to get the best lap, but the fact that he got less than 8 minutes in a 'fahrbericht' is indicative of the GT-R's potenial. Even his second attempt is something well less than 10/10ths of the GT-R's absolute best limit.
    We can only say: Nissan's 7:26 represents something close to an absolute 10/10th limit run. Others ran at something less than 10/10ths. Do you seriously think Rohrl ran the Scuderia at 10/10ths if he was 6 seconds slower than HvS who only did 3 laps??? This is what I've been saying all along and only now are you accepting it: You can't claim cheating by Nissan, you can only say that others should try harder before they start claiming "cheating." And I never, EVER said Nissan's test methods were the same as others.
    Now that you have finally come around and accepted this, then there is nothing more for you to say. Just keep wishing, like the Italian press have apparently, that Nissan are supplying 530-560 hp ringers for testing.
  21. Are you 2 argueing?

  22. ohhh MY GOD. I'm out of order because I've seen a figure like 528hp, or like 519 or even less trying to say that GT-R 7.26 is achieved probably with MORE power than the claimed? Ohhh no. Sorry, I have not the possibility of dynoed the Suzuki's mule, and not being a meteorologist, my English is like a WC flushing, I'm surely uncorrected.
    BUT my mistaken, considering all colud be within the 3%, so WELL within the tolerance. Haha <A BORDER="0" HREF=""><IMG BORDER="0" SRC="pitlane/emoticons/smile.gif"></A>

    The 7.38 about 911 Turbo is not very interesting for me because I don't accept the Turbo with the sport tires (for the concept), and that 7.38 is too much close than the GT2. Sorry, but I'm that.

    I like the GT-R for its configuration of potential, probably I will buy it in future if I will have the opportunity, but GT-R is not my desire because I have some other cars good for me, and "times" or "the time" of the NRing is only a point for talking and not a point of life for me, for my teories and my cars. I have not this wish, the desire of confuting the GT-Rs power in my mind, so we sleep weel anyway. <A BORDER="0" HREF=""><IMG BORDER="0" SRC="pitlane/emoticons/wink.gif"></A>
  23. The GT-R test mule driven by TopGear was beaten in a straight line on the autobahn by the 997.1 Turbo. Suzuki's 7:38 mule hit ~273 kph on the same section of straight where Chris Harris, with a damp lead-up corner, hit 271 kph after only his 2nd lap (1 out lap, one timed flying lap) in a customer GT-R. If Suzuki's mule makes 510-520 hp, then so do customer GT-R's. Att 600 hp, the GT-R's 7:38 STILL wouldn't make any sense so it's pretty lame to even be talking about 520 hp.
    I don't give a crap about whether you care for the GT-R. I already know you don't. That is not the issue.
  24. "Att 600 hp, the GT-R's 7:38 STILL wouldn't make any sense so it's pretty lame to even be talking about 520 hp"
    How you want to arrive, justified something? STILL wouldn't make any sense its "chassis potential? "trasmission potential? "tires? "something other? LEVEL.Yes.
    BUT turn the omelet, you are so sure how seems running the NRing with a 485hp compare to 520hp, than a 600 hp engine? I'm sure you know, but I don't know how we are still here talking about.

    "Suzuki's 7:38 mule hit ~273 kph on the same section of straight where Chris Harris, with a damp lead-up corner, hit 271 kph after only his 2nd lap (1 out lap, one timed flying lap) in a customer GT-R"
    I think the S1s are regulary pretty bit lame than the S2s. Is anyway bit comprensible behind some points IMO, but not being the crucial point, don't tell me to talk about that.please.
    We are talking about all the engine swings, showing dynos for long time, so..

    "I don't give a crap about whether you care for the GT-R. I already know you don't. That is not the issue"
    I know, no problems.
  25. I am saying Nissan don't need to send a 600 hp ringer to lap the 'Ring in 7:26, considering what HvS did with a car that for sure made far, far less than 600. More like the 489 hp of the Auto car. Are you even familiar with what a 600 hp Nissan will do to a stock 997.1 Turbo? I can pretty much guarantee a sock Turbo will not walk away from one on the autobahn like TopGear's car did to the GT-R mule...
    Still doesn't make sense in terms of hp/wt potential. Everyone including yourself were doubting Nissan on the basis of hp/wt. Look at other cars which for sure are rated at 600+ hp officially and lap in 7:20-7:30's: they sure as hell don't weigh 1740kg. Can't all be down to tires because the 650 hp RT12 is on MPSC's and the ZR1's tires can return 1.12g sustained. The Scuderia has

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