vjones

The GTR's numbers are impressive, but I really don't care for the look of the thing? Anyone else feel the same?

Slowgoin

No I don't . To date, it will spit out what ever GM has to feed it.


:

Charlie M

I have to say that the Datsun looks good in back

mousecatcher

and a little bit about the GT-R to boot.

glass slipper

Actually, we do agree as we're saying the same thing. I refer to using a higher gear when there is too much HP for the novice (unskilled). We're just using different terminology. It still doesn't make high HP a bad thing. Using your logic, we should reduce the size of the brakes in case limited traction/skills are encountered because too much brakes can be a bad thing. I've raced in the rain at speeds in excess of 130 MPH and you have to modulate everything...not only throttle, but brakes, steering, and speed.

Thanks for your concern about my math skills, I can assure you it's completely unnecessary. However, I have serious concerns about your physics skills. HP is NOT a unit of work, HP is a unit of power. Maybe when I right HP out as horsepower it's a little clearer to you. You are correct about the AUC the same and HP being different at each of those points. But the AUC for HP and the AUC for torque have completely different meanings since HP is torque*RPM. Or mathematically, x times the integral of f(x) is not the same as the integral of x*f(x). In other words, the units of HP and torque are different and represent two completely different concepts in the world of physics.

Actually, you did say "Torque is what wins races"...go back and look. You did also say AUC for torque so you said both. The Duramax diesel has excellent throttle response, just ask TxChristopher. It is heavy compared to the LS7 but it's lighter than other diesels. But its' torque curve is nowhere close to peaky and narrow. Here's the HP/torque curves for the first generation Duramax:
http://www.jimrobinsongroup.com/car_...duramax.b.html
In the RPM range from idle to redline, 90% of its' torque is available over 71% of its' entire RPM range. You can look at the curve in the power band and see it's about as flat as a table top like most other diesels...I get the feeling you don't have much experience with diesels.

Ok, I can have two dyno graphs from completely different engines where the AUC for torque in the engines' powerbands are equal and peak torques are equal, but one engine makes twice the HP. Which one do you want?? I can have two different engines with one having 1/2 the peak torque as well as 1/2 the AUC for torque in their powerbands and the engine with less AUC and peak torque will have three times the HP. Which one do you want?? These are real life examples with the last one being a comparison between the Duramax diesel and a F1 engine proving it does matter where peak torque occurs and HP is the only thing that matters in a race. Looking at the AUC for torque tells you nothing about the performance of a car. HP is the rate that an engine does work...lap times are the rate that a car will go around the track. They both have a time component therefore you use HP to determine a cars' performance potential. Torque doesn't have the necessary time component...it's just a force. Using the formula F=ma or a=F/m, you can determine the acceleration of the car at that particular instant in time given the gear ratio for whatever gear you're in and the rear end ratio. But then you have to do that for each instant in time to get your time component and go through all the gyrations with the gears if you're really stubborn and are stuck on torque, but in the end, you've just gone the long way through the HP formula where HP=T*RPM/5252. Or do it the easy way with HP. Here's a little more info. If you remember from my post above, I referred to the speed at the end of the 1/4 mile as kinetic energy (KE) added. The units of KE are FT-LB (not to be confused with the units of torque...LB-FT). (The units of work are also FT-LB but the difference is that work is a scalar product of force and the displacement vector over which the force is applied while energy is a scalar quantity which means it has a magnitude but no direction. They are completely different concepts.) Since KE=1/2mv^2, it's obvious that KE varies with the square of velocity. So if your trap speed in the 1/4 is 120 MPH and your ET is 11.5 seconds, you can find your HP by dividing 11.5 seconds into the KE added to get to 120 MPH and arranging units to come up with FT-LB/sec then divide by 550 (1 HP=550 FT-LB/sec). Of course this assumes constant HP (through optimum gearing) and all HP transmitted to the ground with no wheel spin. But it makes for some interesting comparisons. Like the KE added to get to 120 MPH will be four times the amount to get to 60 MPH. The obvious implication is that acceleration isn't constant through the 1/4 with maximum acceleration occurring at low speeds...just what we come up with when we multiply torque times our 1st gear ratio and use a=F/m. See, everything is accounted for using HP...even gearing. If we look at the performances numbers:
http://www.roadandtrack.com/assets/d...6911_chart.pdf
The Z06 is 3.4 sec to 60 and 10.7 sec to 120 while the GTR is 3.4 sec to 60 and 12.7 sec to 120. By the KE formula and using the 0-60 times, the Z06 and the GTR should have gotten to 120 in 13.6 sec. The GTR has enough grip off the line and very steep gearing for 1st gear to maximize HP at the beginning but it's hurt by the large drop in RPM on the 1st-2nd shift and it gets close to its' predicted time based on the formula. The Z06 is nowhere close to the predicted time indicating it doesn't have the traction off the line and it's hurt by gearing not letting it get up on the HP curve until about 40 MPH. Working backwards, the Z06 has the potential to do a sub 3 sec 0-60 run (10.7/4=2.675) if geared properly and with enough traction.

Ok, now I've rambled on. But I do invite you to review the other thread I linked to...and please let us know if you disagree with any of the people I listed.

TxChristopher

I was NOT wrong. Turn in your degrees, your ignorance just out horsepowered your intelligence. Torque is the force that moves the car. Horsepower is not a force, it is a calculation of work. Horsepower does not "move a car" it is merely a calculation in an attempt to determine the amount of work done over time.

I pass, you fail. I thought you were smart. Guess not.

Again, torque is the force that moves the car. Horsepower is not a force, it is only a calculated value that the REAL force (in this case torque) performed.

Furia

and the Datsun V spec just ran a possible 7:25 on Nürburgring... now we just need a lap time from ZR1

maybe you call it a Datsun.. but it's beating just about all the other car makes out there. consider calling it Nissan and it might just ease up the pain a little.

Bugatti Veyron is the fastest cars by acceleration
http://en.wikipedia.org/wiki/List_of...y_acceleration

but it's not the fastest in the ring
http://en.wikipedia.org/wiki/Nordsch...test_lap_times

can't wait to see corvette going heads on with GT-R is GT races..

vtecnitian

damn this tread still open all the others get closed quick

jmrc5

Another engineer here, this time an EE to correct you: Horsepower is not a calculation of work! Work = energy and, in electrical terms, is measured in KWH (see your electric bill). Horsepower is a measure of power (1 horsepower = 746 W = 550 ft-lb/sec). In other parts of the world, you will often see engine power rated in kW. For instance, the LS2 is rated at 298 kW in Australia.

You now have mechanical engineers, electrical engineers, physicists, and mathematicians lined up against you. Are there any chemical engineers available to chime in?

glass slipper

An electric motor makes its' maximum torque at locked rotor (zero RPM), but since nothing is moving, it is doing no work and produces zero HP since the equation HP=torque*RPM/5252 has zero for RPM in the numerator. You can make all the torque you want, but if you don't move anything, it means nothing...once again, HP has the time factor in it which indicates work is being accomplished. But yes, torque is the force that accelerates the car when a sufficient amount is applied to get it moving.

HP is not a calculation of work, it is a measure of the rate at which work is being accomplished...work and HP are two completely different concepts. Yes, HP can be calculated but it can also be measured...how do you think an inertia type chassis dyno works? It takes a roller with a known moment of inertia and measures small increases in RPM of the roller to come up with the amount of kinetic energy added then divides that by the small interval of time in which the kinetic energy was added times a constant to get units of HP. From there, the RPM probe picks up the RPM at which the HP was measured and calculates torque.

HP is not just a calculated number, it is as real as torque or feet or pounds. For a demonstration, 1 HP=~750 Watts...go grab a 75 watt light bulb (about 1/10 HP) and let me know how real HP is. Not only does HP move a car, it determines the rate at which the car will move.

Also, "the amount of work done over time" is energy, not HP...once again, HP is the rate at which work is done. Look at the units in the HP formula when you multiply torque and RPM...LB-FT*rev/min or LB-FT/60 sec. Now look at the definition of HP...James Watt determined (somewhat arbitrarily) that the average horse could lift 550 pounds one foot per second or 550 LB-FT/sec. Just for your info, the pound and foot are arbitrary measures too.

You failed miserably this time...you're way out of your league with this stuff, but nice try.

Minkster

Give it up, he seems to have the IQ of his age divided by infinity (see if he figures that out ). I would suggest use of the "ignore list" feature and save yourself further frustration. As a wise man once said, "never argue with a idiot for fear of being taken for one".

Suaveat69

The ring time was that not with a flying start, 100 ft. lead off the line when the timer started and 400-500 ft from the finish line when the timer was started?

There was a post on here with actual pictures. Let's wait and see what a stock production one does with a line to line stop/finish and a standing start.

Bigbucks

Ok, I give up. In an earlier post I said HP and Q were the same things. I should have been more careful. Yes, these are different parameters having different 'meanings'. In the context of the discussion, someone said you need to look at the area under the Q curve, not the hp curve, when comparing engines (all else being equal, of course).

My POINT was that if engine #1 has 20% more area under the torque curve compared to engine #1, then the hp curve will also have 20% more area under the curve compared with engine #2. The plots of Q vs rpm and hp vs rpm provide the same information about the engine's output characteristics, so it doesn't matter whether one compares the Q curves or hp curves, becasue knowing one means knowing the other (no EXTRA information is conveyed by looking at one vs the other).

And in the quote above, at face value this doesn't SEEM to be correct, since equal Q areas means equal hp areas (unless there is more to the description than is written).

Allthrottleandsomebottle

Not now...............

Post ANY GT-R related stuff here...........sticky thread at the top of this forum
http://forums.corvetteforum.com/show....php?t=1988356