340Elise

I know exactly what you are talking about, but I believe they are talking about wheel hp.

What I remember about the old measurement vs. the new measurement is that both of them are at the crank, but the old one did it without any of the accessories at all (just like you wrote). The new one is still at the crank, but with all the accesories on the motor except for the drive-train.

I believe this because they quoted 15% drive-line loss, which is the usual number used to calculate the difference between wheel and crank hp.

Also, why would they be talking about the old rating system from over 30 years ago that no one uses anymore. I think it would be very odd for them to mention this.

340Elise

Now I am curious; this is the power it makes on an ENGINE dyno:

GT-R Engine Dyno

Can anyone help with translating the hp and torque chart at the beginning, and anything else that is printed in Japanese?

SpeedGeek

No way. The distinction between wheel hp, net hp and gross hp is well known. They did not mention wheel hp at all. It would be ridiculously sneaky or disingenuous to state net hp when you actually mean wheel hp. If you are correct, then I would suddenly lose a great deal of respect for Nissan's company ethics.

This thread seems ridiculous to me. Why is it so unimaginable that a well-designed 21st century chassis may be capable of bettering a half century old one? The GTR is not exactly cheap, so I assume there is some serious engineering involved. I'm astonished by the infantile levels of insecurity I'm reading here.

I love my RS because of how awesome it feels to drive. I prefer it to the Gallardo and even the F430 (mostly). I have not driven an R8 or GTR, but I suspect neither will feel as fun as the GT3. And as to which of these is faster around a track is to split hairs so fine that it just doesn't matter to me.

EX1K

Weren't both these cars developed and tested on the 'Ring? With the factory's best driver. So what were the times? I assume they are posted somewhere. That should end the debate no?

Boxster Coupe GTS

It's also interesting to read evo's comments in their comparison of the Skyline GT-R with 271bhp/ton(?) and the Audi R8 with 270bhp/ton...

"I don't believe the Nissan has 473bhp. It weighs almost 200kg more than the 414bhp Audi, which should even things up, but the thump in the back when you nail the Nissan is so strong it feels more like 550bhp..."

SpeedGeek

One word: TORQUE. The turbo Nissan makes 430 lb-ft, compared with the Audi's n/a 320 lb-ft. Evo's comment above is just stupid. The "thump in the back" is torque, and says nothing about the engines maximum power output. Truth is, it's not really possible to "feel" an engines maximum power, which is more a mathematical calculation (max rate of doing work) than anything measurable by the seat of the pants.

How can a thump in the back at say 3000 rpm tell you anything about the max power an engine makes at its peak, which may be many thousands of RPM higher? In fact, hit the gas at peak power revs, and you'll feel very little thump at all.

A 996 TT will thump you in the back much harder than a (lighter) 997 GT3, yet it makes about the same maximum power as the GT3.

Tommy69

It's not only torque, but also at which RPM. An example will be that you will get more kick in the butt with 295 lb-ft at 7000 RMP, than 295 lb-ft at 3000 RPM due to the gear ratio... or do I think wrong?

/Tommy

SpeedGeek

The same engine torque will obviously kick harder in a lower gear than higher. But engine revs should not make a difference if the torque numbers and gear ratios (and weight) are the same.

Imagine 2 cars identical, except one has an engine that makes peak torque at 3k rpm while the other makes the same peak torque number, but at 6k rpm. The first car will kick you in the back exactly the same at 3k rpm as the 2nd car kicks at 6k rpm. Yet the first car will be making exactly half the horsepower at 3k rpm as the 2nd car makes at 6k rpm. You "feel" torque by the kick, but you can't feel power.

You can sort of "sense" power, though. If your car continues to provide thrust as revs and speed rise, you sense that the engine is powerful. But the thrust itself is torque, not power.

Tommy69

Yes you have right, but those two cars in your example will most likely not be designed with the same gear ratios (then you will not take advantage of the characteristics of the engine). Would be interesting to compare the GT3 with the turbo, and see how the final gear and the individual gears will impact the torque out on the wheels.

/Tommy

340Elise

If they stated net, but it was actually wheel hp, then they would be underating the car. That is not as bad as the other way around, correct? On top of that, they did put an asterisk by the hp number and an explanation below. What caught my attention was the fact that they were talking about 15% drivetrain loss from their net hp number. I always thought that was the difference between the new crank hp measurement and hp at the wheels.

Is it also true that the old gross hp at the crank (without any accesories on the motor) vs. the new crank hp measurement with all the accesroies included is also about a 15% loss? If so, then I see your point about the old gross and they have their number as net. But again, this seems like an odd comment to me since cars have been rated with the new net crank hp number for a long time now, and the old gross hp number is all buy forgotten. Do you see my point here?

I agree 100% that the Nissan should be able to beat the GT3, and that they have the knowledge, technology to do it. I don't understand why this thread is ridiculous? This is a car forum and we dicuss cars here, and they are not always the GT3 and GT2. What is wrong with looking at the competition and seeing how it achieves it phenomenal performance figures. I for one have never thought my GT3 is the fastest street legal car on the track.

I know it is a lot of fun to drive, and it has very high limits; bujt it is not the fastest. I personally like the GT-R and have been to the dealer to get more infoand I have considered ordering one since I would get it at MSRP and they still had 3 allocations left the last time I was there.

Some may be insecure, but I assure you I am not one of them. I also think you are reading into the posts way too much. I want to learn more about the GTR and see how it does when some real tests and magazine articles become available.

Also, don't forget that the Lotus Exige S 240 is also a threat to the GT3 on the slower, tighter tracks, and could very well beat our GT3's also. So what?

Agreed. May we continue with this thread, or do you think it is infantile if we do? I don't want to rub anyone the wrong way or upset them.

Stephen

Boxster Coupe GTS

New R35 GT-R dyno test...

No sooner had my new R35 landed, we wanted to test what she could do on the dyno in totally stock form, before we got to work tuning her.

Official word from Nissan is the R35 GT-R’s maximum power is 473bhp (480PS/353KW) at 6400rpm. The car is totally factory standard (though soon to be tuned), is running standard boost and is just run in. Before putting on the dyno, we did a quick oil change with Castrol Edge, as the car saw some track action last week. Using BP Ultimate 102 unleaded, the car recorded a staggering 520 bhp @ 6,617rpm !!!

Ben Linney says: "We were fairly shocked but pleased with the results, Nissans offical figures are 473bhp at 6,400rpm so this result is very pleasing – a 47bhp increase!"

GTR_Dyno_Test_link







[Ben Linney of GTC RACING TECHNOLOGY]

SpeedGeek

I've seen dyno tests from reputable companies that show stock 996 GT3s making 420 bhp. Dyno tests are certainly useful for tuning engines, but not so useful for comparing actual figures against claimed ones. There's just too much variance of conditions involved. A 10% range seems about right, though. BTW, how much power are you hoping to get from that engine once it's tuned?


I do. However, I think it would be even more odd that they would use a known term like "net power" when they actually mean another known term "wheel hp". That would be extremely disingenuous. If that is in fact the case, it would not leave me with much respect for them.

Stephen, don't take me so seriously, I was certainly not trying to come across as an ***. Sorry 'bout that. Please go on with the thread.

Boxster Coupe GTS

Nissan GT-R dyno: 475hp at the hubs...

"A few days ago we were talking about Nissan wanting to get the GT-R to an SAE-certified 480hp so it would match the Porsche 911 Turbo, one of its chief rivals. It looks like that should be an easy feat if the dyno numbers coming out of Japan today are solid - and it looks like they are. According to testing done on a Dynapack dynamometer, the new GT-R pumps 482PS (475hp) to all four hubs, with torque peaking at 580Nm (428lb-ft) at the hubs.

Assuming parasitic drivetrain losses around 15% - although the loss could be even larger given the GT-R’s all-wheel drive platform - that would put power at the crank around 550hp and 495lb-ft of torque - absolutely insane numbers for a 3.8L engine, twin-turbo or not. Suspicious? Head on over to NAGTROC, the North American GT-R Owners Club forums, where poster Chuck H has links to photographic evidence of the testing, complete with shots of the dyno screen.

While these numbers seem to fit more aptly with the GT-R’s 3800lb curb weight and its scorching ‘Ring times, it still seems odd that a car with a drag coefficient of 0.27 would top out at anything under 200mph with 550hp under the hood. Maybe there’s more to this story than meets the eye. We’ll keep you updated as things unfold..."

Motor-Authority_GT-R_article_link

SpeedGeek

The great thing about turbos is that they can be tuned to incredible power. Keep us informed, and thanks for posting.

BTW, I may be in the minority, but I think the GT-R looks fanatastic in a sort of Darth Vader way. If only it were 500 lbs lighter...

SpeedGeek

Hey, I just noticed that your 520 hp result was on 102 octane fuel. As it's a turbo, the fuel could make a meaningful difference if the ECU can take advantage of it. Just wondering what the result would be with pump gas?


BTW, what are the quarter mile times for the GT-R? Trap speed can be a good indicator of power.