Nov 4, 2009 7:59:25 PM
- PorSchelover1
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Board: Porsche - 911 - 997 - Turbo
Language: English
Region: Worldwide
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Nov 4, 2009 8:41:27 PM
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MKSGR
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Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
you are wrong , ny friend
in this very drag race the switzer p800 wasn't tuned properly - it;s a complete and sophisticated package
later there were some more races netween those cars and P800 humiliated 911TT every time...
More over, my friend, this P800 set up a new becnhmark offically - 0-300 in 19.81 secs... it is in Veyron territory.. 911 TT SPI750 made 0-300 in 23-24 secs at its best...
and if you look properly in the tech stats - GT-R has better drag coefficient thatn 911 Turbo...
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
artur777:
you are wrong , ny friend
in this very drag race the switzer p800 wasn't tuned properly - it;s a complete and sophisticated package
later there were some more races netween those cars and P800 humiliated 911TT every time...
More over, my friend, this P800 set up a new becnhmark offically - 0-300 in 19.81 secs... it is in Veyron territory.. 911 TT SPI750 made 0-300 in 23-24 secs at its best...
and if you look properly in the tech stats - GT-R has better drag coefficient thatn 911 Turbo...
I see - we made one big mistake: we focused on the facts as presented in various videos - in all these videos car sucks a bit. Of course, we could not know that this pretzel GTR is ultra-fast as soon as the cameras are all switched off 
Great product - performance seems to be more volatile than stock markets in the financial crisis however 
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Not sure about superior aerodynamics...
__________________________________________
Factory claimed GT-R Cd: 0.27
Actual GT-R Cd, as tested by Sport Auto: 0.31
Actual GT-R CdA, as tested by Sport Auto: 0.71
Lift at 200 km/h at front axle: +3 kg
Lift at 200 km/h at rear axle: -8 kg
___________________________________________
Factory GT2 Cd: 0.32
Actual GT2 Cd, as measured by Sport Auto: 0.32
Actual GT2 CdA, as measured by Sport Auto: 0.66
Lift at 200 km/h at front axle: -9 kg
Lift at 200 km/h at rear axle: -29 kg
___________________________________________
Factory claimed Turbo Cd: 0.31
Actual Turbo Cd, as measured by Sport Auto: 0.29
Actual Turbo CdA, as measured by Sport Auto: 0.59
Lift at 200 km/h at front axle: +8 kg
Lift at 200 km/h at rear axle: -12 kg
___________________________________________
Nov 8, 2009 12:45:25 PM
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Carlos from Spain
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- Reply to: Crash
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Good stuff Crash 
that claimed Cd of 0.27 for the GT-R is almost the Toyota Prius' Cd (0.26) 
artur777:and if you look properly in the tech stats - GT-R has better drag coefficient thatn 911 Turbo...
My friend, you do know that the Drag coefficient (Cd) is not the same thing as the actual drag (CwxA or CdA) that MKSGR is talking about right? the Cd is only part of the equation for the real drag as it only reflects on how "slippery" the shape of object is but independant of the vehicle's size.
You can't just use the Cd to compare the actual drags of two vehicles. The actual drag depends on the Cd, the vehicle's frontal area, the air density and especially the speed of the vehicle (drag=Cd x area x air density x speed squared).
So for a given equal air density and speed, to compare the actual drag you need the Cd AND the frontal area as well... and have you seen the size of the GT-R's front? its huge, hence its CdA.
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Nov 8, 2009 3:12:19 PM
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Carlos from Spain
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Reply to:
MKSGR
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Indeed, I would credit that CdxA increase to the more aggressive aerodinamic kit of the GT2 trading Cd for more downforce, and a "bit" from the wider tires as well. I wonder if in the case of the 911 Turbo they measure the Cd with the wing up or down 
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Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Those "actual" numbers were based on mathematical calculations
The variables include weight, cross sectional area, velocity versus time, rolling resistance, wind, slope, etc. It is based on time to decelerate between two points, and it makes some assumptions, like the force of rolling resistance is constant independent of velocity.
I do not believe it would be fair to compare wind tunnel numbers against calculated Cd, especially since we don't know the conditions of the test, which would be variable even all cars were tested simultaneously.
Nov 8, 2009 3:49:24 PM
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MKSGR
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Reply to:
Carlos from Spain
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Carlos from Spain:I wonder if in the case of the 911 Turbo they measure the Cd with the wing up or down
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That is a very good question! Comparing the 997TT and the GT2 at high/very high speeds on the AB I am even more impressed by the performance delta given these CdxA numbers (also keeping in mind that the gearing is longer in case of the GT2)... The GT2 delivers amazing performance.
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
bbywu:
Those "actual" numbers were based on mathematical calculations
The variables include weight, cross sectional area, velocity versus time, rolling resistance, wind, slope, etc. It is based on time to decelerate between two points, and it makes some assumptions, like the force of rolling resistance is constant independent of velocity.
I do not believe it would be fair to compare wind tunnel numbers against calculated Cd, especially since we don't know the conditions of the test, which would be variable even all cars were tested simultaneously.
All three tests were done at the same Daimler wind tunnel test facility, under the exact same conditions.
Carlos, the 997TT aerodynamic figure is with the wing up and yes, the GT2 has a more aggressive aerodynamic profile (just look at the downforce figures).
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
MKSGR:
Carlos from Spain:I wonder if in the case of the 911 Turbo they measure the Cd with the wing up or down
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That is a very good question! Comparing the 997TT and the GT2 at high/very high speeds on the AB I am even more impressed by the performance delta given these CdxA numbers (also keeping in mind that the gearing is longer in case of the GT2)... The GT2 delivers amazing performance.
Very true. The GT2 is an amazing performer and looks good as well.
Nov 8, 2009 11:28:20 PM
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Carlos from Spain
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- Reply to: Crash
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Crash:All three tests were done at the same Daimler wind tunnel test facility, under the exact same conditions.
Carlos, the 997TT aerodynamic figure is with the wing up and yes, the GT2 has a more aggressive aerodynamic profile (just look at the downforce figures).
Excellent Crash 
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Nov 8, 2009 11:49:14 PM
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Carlos from Spain
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Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
You gotta love Nissan... claimed Nring lap time... LIE, claimed HP figure.. LIE, claimed Cd... LIE! 
... they even included a transmission self-destruct button on the dash and labeled if "VDC Off" which also self-desctructed your warranty as well! 
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Nov 9, 2009 11:47:21 AM
- Joost
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Reply to:
Carlos from Spain
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Carlos from Spain:
You gotta love Nissan... claimed Nring lap time... LIE, claimed HP figure.. LIE, claimed Cd... LIE!
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I wonder how that works... "Let's make up a number for the Cd value now... anybody? What you say? Is it actually 0.99? Hmm, doesn't sound nice. I propose 0.27. Anybody agaianstthisvalueno?Allright, 0.27 it is!" :D
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Porsche, seperates LeMans from LeBoys
Nov 11, 2009 4:32:50 AM
- xandi911
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Reply to:
Carlos from Spain
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Carlos from Spain:
You gotta love Nissan... claimed Nring lap time... LIE, claimed HP figure.. LIE, claimed Cd... LIE!
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Nov 11, 2009 5:59:45 PM
- fritz
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Reply to:
Carlos from Spain
Re: 997TT 750hps vs GT-R 800hps - THE VIDEO!!!
Carlos from Spain:
You gotta love Nissan... claimed Nring lap time... LIE, claimed HP figure.. LIE, claimed Cd... LIE!
C'mon, Carlos. 
You should at least give them credit for being consistent.
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fritz
Nov 11, 2009 7:08:12 PM
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Carlos from Spain
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