Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
MKSGR:
Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
+1 on the wrong gear, GT2 is a beast on the highway
MKSGR:
Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
The GT2 consistently gets off the mark later than the Turbo (Note: later, not just slower), as if the GT2 driver was not as well prepared. Any gains resulting from PDK would not kick in until later.
If they hadn't been doing this on public highways , I'd say that maybe the drivers should swap cars and try the test again to see if they got the same results.
fritz
there is no doubt IMHO....
the PDK will jump always... i think the GT2 must catch it after 200... but in the video IF the GT2 owner really started in wrong gear, he must start catch the PDK... and looking the video this thing doesnt happen...
the pdk is BEAST
I have driven a lot of fast cars including the Carrera GT and I am telling you guy's that the 997.2 Turbo PDK is a beast. It is unbelievably fast.
I suspect it will stay with the CGT for a very long time before hp takes over.
Fritz, I agree that the GT2 is slow on the trigger but it don't believe it would have caught the Turbo. The margins were fairly substantial.
BiTurbo:
MKSGR:
Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
+1 on the wrong gear, GT2 is a beast on the highway
Wrong gear? I don't think so. This was a well prepared comparison between the two, why on earth should the GT2 be in the wrong gear every time?
The secret of life is to admire without desiring.
for what its worth, this is from another (US) forum:
"I ran my friends brand new 997TT w/ PDK and the chrono overboost.
I was trying to be nice, run him on pump gas where I only make around 590 or so whp (my car makes around 740 or so, more if I really turn up the boost on C 16).
I gave him a 2 car jump thinking I could easily reel him back in and I could only close one length. We went w/ out me giving him the jump and I was barely pulling a length on him. Mind you I have every bolt on possible and Gt 30 turbos. Yes I would crush him on race gas but the 2010 TT w/ PDK and overboost is the fastest stock car I have ever ran.
I was really impressed."
Rossi:
BiTurbo:
MKSGR:
Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
+1 on the wrong gear, GT2 is a beast on the highway
Wrong gear? I don't think so. This was a well prepared comparison between the two, why on earth should the GT2 be in the wrong gear every time?
That's probably a question to ask the driver Honestly, this video highlights just one effect: the 997TT starts accelerating earlier in each trial. As the acceleration test stops at rather low speeds this effect of earlier acceleration just carries on until the end of the acceleration runs.
What other explenations (i.e. other than driver or wrong gear) for this observation could exist? The only other idea I could come up with is reduced turbo lag in case of the "smaller" chargers in case of the 997TT (this, however, would most likely result in weaker turbo power at higher speeds...)
From 0-100 kph and from 0-200 kph, the 997 Turbo S will always beat the GT2
Things look different at speeds over 250 kph.
From 0-100 kph, there aren't many cars on this planet which can beat the 997 Turbo or Turbo S.
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (April 9th, 2010), BMW M3 Cab DKG, Mini Cooper S JCW
Rossi:
BiTurbo:
MKSGR:
Very simple: GT2 seems to start in wrong gear. The turbo just gains at the beginning (when the GT2 suffers from signifcant turbo lack, for whatever reason). This advantage then carries on.
No doubt, the GT2 should be faster at higher speeds.
+1 on the wrong gear, GT2 is a beast on the highway
Wrong gear? I don't think so. This was a well prepared comparison between the two, why on earth should the GT2 be in the wrong gear every time?
I've tested my GT2 against a GTR with minor upgrades and he had no chance in catching upto me at 200km/h, we decided to go from 100km/h (or maybe it has something to do with my cat delete ?)
RC:
From 0-100 kph and from 0-200 kph, the 997 Turbo S will always beat the GT2
Things look different at speeds over 250 kph.
From 0-100 kph, there aren't many cars on this planet which can beat the 997 Turbo or Turbo S.
997TT/TTS with PDK has quite an advantage in a launch from 0kph. My expectation would be that the TT/TTS does not have an advantage if accelerated from an initial speed of >50kph or so. There should be then another advantage for the TT/TTS at up-shifts at higher speeds (>150kph) as the PDK shifts very quickly and the GT2 suffers from adverse aerodynamic effects while the gear is being changed. The GT2 will benefit when the power can work without interruptions from manual gear changes
Guys, it is all in the PDK working with the boost.....
The PDK will wring every last bit out of the power curve (when in sport mode) when the driver boots it and bang mercilessly into the next gear.
The thing to get our heads round is how fast the gear change is and how the boost is maintained during the change. When one plots the PDK changes there is barely a blip in the longitudinal Gs, the PDK turbo just keeps on accelerating.
Contrast this with the GT2...... below is a trace from mine changing second to third gear. The actual gear shift time was reasonably quick with the "zero acceleration" portion of the change being around 0.35s - what one has to appreciate and is demonstrated well in the graph below is how the acceleration tails off as the clutch is depressed and then how it returns to full acceleration once in the new gear - it actually takes 1.77s for the acceleration to return to full fat ~530PS style acceleration. In contrast the PDK will be accelerating at full whack for virtually this whole 1.77s....... there is the small matter of 67 metres covered by the GT2 during this "less than full whack" gearchange accelration phase !!!!
The PDK technology renders manual shifts obsolete for drag racing
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2009 997 GT2 659PS/827NM DIN
TB993tt:
Guys, it is all in the PDK working with the boost.....
The PDK will wring every last bit out of the power curve (when in sport mode) when the driver boots it and bang mercilessly into the next gear.
The thing to get our heads round is how fast the gear change is and how the boost is maintained during the change. When one plots the PDK changes there is barely a blip in the longitudinal Gs, the PDK turbo just keeps on accelerating.
Contrast this with the GT2...... below is a trace from mine changing second to third gear. The actual gear shift time was reasonably quick with the "zero acceleration" portion of the change being around 0.35s - what one has to appreciate and is demonstrated well in the graph below is how the acceleration tails off as the clutch is depressed and then how it returns to full acceleration once in the new gear - it actually takes 1.77s for the acceleration to return to full fat ~530PS style acceleration. In contrast the PDK will be accelerating at full whack for virtually this whole 1.77s....... there is the small matter of 67 metres covered by the GT2 during this "less than full whack" gearchange accelration phase !!!!
The PDK technology renders manual shifts obsolete for drag racing
Interesting post (and chart) The video though, suffers from the GT2 starting off later (in all trials) than the 997TT. Obviously, this cannot have much to do with PDK performance and boost handling
MKSGR:Interesting post (and chart) The video though, suffers from the GT2 starting off later (in all trials) than the 997TT. Obviously, this cannot have much to do with PDK performance and boost handling
I didn't make it very clear but what I think the PDK does which our GT2s cannot is the way the whole "system" reacts to a violent WOT input. In the GT2 say in second gear at 4000rpm (which is probably about the speed the drag in the video takes place) when we hit the throttle WOT yes it will jump ahead but I think the PDK has a shorter 2nd gear than the GT2 and it has a higher static CR and it has Dfi - the thing is ultra responsive and it will light it turbos up faster than the GT2 so it will accelerate faster for the ~2 seconds it takes to go from ~75kph to the gearchange point, once the PDK shifts it will make the massive differnence shown in the graph and its game over GT2.....
It is fascinating discussing effectively the "responsiveness" of our engines, this is so important and affects our driving experience evry second we are behind the wheel yet so many people ignore it..... I was amazed experiencing the 9ff 1000hp cars at a local event, they accelerated from 250-350kph very quickly but my GT2 was faster to 250kph as their big turbos were just so unresponsive....
2009 997 GT2 659PS/827NM DIN
Toby, thanks for the detailed explanation, and it basically supports with objective measurements the hypothesis i had in mind. the key factors being 1) quicker spool / response due to the smaller turbos; 2) faster shifting leading to virtually "full-boost" shifts. and probably also shorter gearing, with the PDK having 7 speeds vs the GT2's 6.
the videos were not intended to be a scientific test by any means, but just for fun, and to document somewhat "real world" (or "real" for THIS part of the world) conditions. there are optimal situations where the cars may perform better-- as the video showed for instance, starting from approx 130kmh, the Z06 actually beat the PDK by half a car length or so. but in most other situations-- i.e., from very low speeds, or in poor traction situations, or where you just don't have the room to run to 250kmh and beyond, etc-- the new PDK Turbo is all-round the complete package.
obviously things change on the track, but that is much harder to "test" and document on these videos, as driver skill is at least as important as the car itself...
I have not driven a PDK Dfi turbo but I have driven (hard) a PDK Dfi Carrera S and I could not believe the responsiveness of the engine, massively more so than non Dfi and the way it worked with the PDK made it feel mega accelerative.
I have said before on here, RS Tuning in their expensive Mezger builds use bigger displacement with higher static CR and the way they do the timing advance lights the turbos up much faster and makes their Mezger engines very responsive, even mine with stock CR (which in itself can vary from the factory) and capacity feels much more responsive than stock tune whose timing advance is tuned to cope with lower octane fuels (mine is mapped for 100 RON)
This post has me day dreaming about that 4 litre conversion RS are carrying out on the 997.2 Dfi engine which they broke............ that thing and PDK will require a neck brace for street drivning
2009 997 GT2 659PS/827NM DIN
The key to PDK's success is maintenance of boost.
I tried to look at the boost gauge under full throttle when I drove the PDK Turbo a few weeks ago. The car was so fast that I stopped trying after a couple of tries; for fear of running into something and kill the car, and myself, in the process.
From the quick .2 sec glances, the boost did not drop at all, as expected.
There are two ways that I think the GT2 might equal or beat this PDK bad boy:
1. Power shifting (and leave your gear box on the sidewalk).
2. Rolling start at 100 mph. LOL. Kidding aside, the idea is any shift at all, especially the lower gears -- 3rd and below, and you are toast against a PDK Turbo.
A Lambo LP 560-4 with e-gear would be a worthy competitor. But... since that car doesn't do 3 flat 0-60, I think the PDK Turbo will have it for lunch, easy. This car is an amazing accomplishment for Porsche.
--
Regards,
Can
997 Turbo + Bilstein Damptronic "Stage 2" ( Review ) + GIAC ECU Tune ( Fast as a torpedo & reversible to stock - Review ) + Cargraphic Exhaust ( Oh heavenly noise! )
Apr 12, 2010 7:18:50 PM
Apr 12, 2010 7:27:09 PM
Once the gear boxes are equalized between any 2 cars, I would assume that the outcome will be determined by power/weight ratio, traction, and drag coeffecient. Not much has been mentioned of the Turbo's 4WD system but to me that is another very important key to the equation, particularly from a standing start.
Really, it's like the "perfect storm": turbo power + 4wd traction + pdk = hell breaking loose. Aka the fastest mass production car in the world.
Back to PKD, fast shift alone is one part, but it's not all. The whole key to me is that right foot -- do anything so you don't lift the right foot (power shift, whatever), then forward momentum is better maintained, then you have a better chance against this bad boy.
--
Regards,
Can
997 Turbo + Bilstein Damptronic "Stage 2" ( Review ) + GIAC ECU Tune ( Fast as a torpedo & reversible to stock - Review ) + Cargraphic Exhaust ( Oh heavenly noise! )
cannga:
A Lambo LP 560-4 with e-gear would be a worthy competitor. But... since that car doesn't do 3 flat 0-60, I think the PDK Turbo will have it for lunch, easy. This car is an amazing accomplishment for Porsche.
I like your words....
By all the theoretical discussions lets not loose the right view on the daily value using PDK or manual as in the GT2. How often we accelerate from 250 kp/h to > 300 kp/h? In this dicipline the GT2 might have an advantage. But in my daily experience I more often accelerate from standstill and from the midrange like 120 to 200 kp/h. Here the Turbo PDK seems to be the better choice...
Conny997:
cannga:
A Lambo LP 560-4 with e-gear would be a worthy competitor. But... since that car doesn't do 3 flat 0-60, I think the PDK Turbo will have it for lunch, easy. This car is an amazing accomplishment for Porsche.
I like your words....
By all the theoretical discussions lets not loose the right view on the daily value using PDK or manual as in the GT2. How often we accelerate from 250 kp/h to > 300 kp/h? In this dicipline the GT2 might have an advantage. But in my daily experience I more often accelerate from standstill and from the midrange like 120 to 200 kp/h. Here the Turbo PDK seems to be the better choice...
Guys... Don't forget the official specs of the two cars... The 997TT should be tad quicker from stand-still. However, I would not expect it to be faster in real life traffice situations - even at speeds below 250kph In contrast, if the GT2 is driven properly it should be faster in most situations. At least the 997TTS should be required to "keep-up" with a well driven GT2.
MKSGR:
The 997TT should be tad quicker from stand-still. However, I would not expect it to be faster in real life traffice situations - even at speeds below 250kph In contrast, if the GT2 is driven properly it should be faster in most situations.
...exept the "rarely" weather condition in Europe like wetness, snow and other grip affecting surfaces...
Conny997:
MKSGR:
The 997TT should be tad quicker from stand-still. However, I would not expect it to be faster in real life traffice situations - even at speeds below 250kph In contrast, if the GT2 is driven properly it should be faster in most situations....exept the "rarely" weather condition in Europe like wetness, snow and other grip affecting surfaces...
Damn... I forgot those little details
cannga:
The key to PDK's success is maintenance of boost.
I tried to look at the boost gauge under full throttle when I drove the PDK Turbo a few weeks ago. The car was so fast that I stopped trying after a couple of tries; for fear of running into something and kill the car, and myself, in the process.
From the quick .2 sec glances, the boost did not drop at all, as expected.There are two ways that I think the GT2 might equal or beat this PDK bad boy:
1. Power shifting (and leave your gear box on the sidewalk).
2. Rolling start at 100 mph. LOL. Kidding aside, the idea is any shift at all, especially the lower gears -- 3rd and below, and you are toast against a PDK Turbo.A Lambo LP 560-4 with e-gear would be a worthy competitor. But... since that car doesn't do 3 flat 0-60, I think the PDK Turbo will have it for lunch, easy. This car is an amazing accomplishment for Porsche.
NO MATTER HOW YOU CHANGE THE GEAR....
POWER shifting or NASA shifting;;;
THE PDK WILL ALWAYS IN FRONT OF YOU!!!!!!!
and like you said when slower the SPEED more advantage this sistem puts against a human manual.
from 4th to 5th gear and UP the PDK doesnt help that much because in these kind of speeds the acceleration is what matters and not the way or speed of CHANGE.
Guys , the Gt2 requires some shifting point knowledge apart from fast shifts... if the driver delays shifting after the shifting indicator lights up the car will have massive lag on the next gear start..the later the driver shifts exceeding the shift light the worse lag it will get on the following gear..
Also the GT2s sweet spot is from a 3rd gear 100kmh roll... other than that you will lose a few tenths of a second to get from 100-200...
I raced my freinds modified slr 722 with a ecu and pulley upgrade.. about 730 hp... from a 2nd gear 70 kmh roll ( shifting just before redline) i would get the jump and start slowly walking away but between eah shifts he will start pulling on me slowly until the car recovers from turbo lag..till 300 kmh..
We raced again from a 3rd gear 100kmh roll ( shifting with shift indicator) the GT2 kept pulling away and the 722 had no chance to pull the Gt2 even at the shifting points..
My is obviously not stock and has the RS tuning 600 hp package with no cats..
xandi911:
from 4th to 5th gear and UP the PDK doesnt help that much because in these kind of speeds the acceleration is what matters and not the way or speed of CHANGE.
In contrast, I would even expect the PDK advantage to be bigger at higher speeds. The reason for this is aerodynamics: while the PDK car continuous to accelerate during gear-changes the manual car's speed drops (while you change gears) given the adverse aerodynamic effects which are quite substantial at higher speeds. if you travel at, let's say, 70 meters per second (200kph) 0.4s of shift-time in combination with massive aerodynamic effects will result in quite a disadvantage...
MKSGR:
xandi911:
from 4th to 5th gear and UP the PDK doesnt help that much because in these kind of speeds the acceleration is what matters and not the way or speed of CHANGE.
In contrast, I would even expect the PDK advantage to be bigger at higher speeds. The reason for this is aerodynamics: while the PDK car continuous to accelerate during gear-changes the manual car's speed drops (while you change gears) given the adverse aerodynamic effects which are quite substantial at higher speeds. if you travel at, let's say, 70 meters per second (200kph) 0.4s of shift-time in combination with massive aerodynamic effects will result in quite a disadvantage...
i would say not just for aerodinamics...
the pdk in lower gears is almost unbeatable, because in lower gears you have a strong G's, fast acceleration, lets say 0,4 sec of a change in a normal car, will represent in a 500hp car, for example 8km/h(just an example)... thinking both cars with similar power, one PDK the other NO, even if the manual one had 600hp vs 500hp in the pdk, the 600hp car will not take 8km/h in a low gear, it could take half car lenght in a 2nd gear for example, the pdk even with 100hp less in the change will take this half and put another half because while the manual is changing the pdk is still accelerating.
BTW, this situation in a higher gear 4th, and up, the 100hp more of the manual one, will represent SO MUCH MORE ACCELERATION, and in this case, even if the pdk take lets say now, only 2km/h in the change of the manual, 100hp in a high gear, is so much more acceleration than one with 500....
i dont know if my bad english i could explain exactly what i would like to say but...
if you are a PDK OWNER and will race a very very strong car, you must start 1st rolling, or in the max 2nd rolling, affter that the pdk will not have to much to do for you.
After 4th gear, what really matters is POWER.