DFI 997 Turbo w/PDK versus 997 GT2
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Gear ratios for a stock 997 GT2 (iA):
1st 3.15
2nd 1.89
3rd 1.40
4th 1.09
5th 0.89
6th 0.73
Final ratio iZ=3.44
With a rev limit of 6750 in gears 1-5, theoretical Vmax in each gear should be:
1st 49 mph
2nd 82 mph
3rd 110 mph
4th 142 mph
5th 174 mph
6th 212 mph
So a 60-130 run could be done from a 3rd gear start into 4th with a single shift, and drop your to drop the time a little. From the vbox tracing, it appears your friend pushed from 2nd, shifted to 3rd then fourth. If he had started from 3rd, he would have saved about 0.3 to 0.4 seconds by eliminating a shift.
However, for comparison of street driving where you aren't prepping to do a dedicated 60-130 run, PDK most certainly shines.
Last edited by bbywu; Apr 25, 2010 at 11:30 AM.
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my videos posted above recently raised a lot of questions, so i tried a different approach this time, measuring both cars' 60-130mph times on a VBox. while the data was taken on two separate days, atmospheric conditions were basically the same:
- 88-89 deg F
- approx 80% relative humidity
both cars were also on the same gas, the equivalent (roughly) of CA 91 octane, at best.
both cars are 100% stock.
bottom line seems to be: 60-130mph, the two cars are basically just as fast as each other, BUT ONLY IF:
1) the GT2 is already ON BOOST;
2) the GT2 driver doesn't flub a shift
critically, it seems that the GT2 is indeed faster, as the speeds rise, and its the PDK's silly shifting that keeps it in the game.
<TABLE class=ncode_imageresizer_warning id=ncode_imageresizer_warning_1 width=900><TBODY><TR><TD class=td1 width=20>
</TD><TD class=td2 unselectable="on">This image has been resized. Click this bar to view the full image. The original image is sized 1024x397 and weights 204KB.</TD></TR></TBODY></TABLE>
from here you can see:
1) GT2 (blue line from bottom left corner to top right corner) is accelerating harder in each gear, but each time there's a shift, if falls behind again. in contrast, the PDK (orange line) acceleration is just seamless;
2) more importantly IMO, the GT2 is accelerating harder at the end. the slope of the PDK's acceleration curve is flattening out, whereas the GT2's is still looking pretty strong. FWIW, ave long-G's over the last 30mph or so of the run has the PDK is pulling about 0.28 G's, while the GT2 is pulling 0.31 G's.
finally, the PDK was actually going DOWNhill overall for this run (total elevation change was roughly -2 meters) while the GT2 was going UPhill, with a total elevation change of around +3 meters.
i know there's a way to normalize the numbers for the difference in level change, but someone will have to figure that one out for me
My take-away from all this is that in an ideal world, with a perfectly level surface, and with perfectly timed shifts, and with both cars on boost at the same time, YES the GT2 would be ahead.
but in the real world, the PDK driver holds the advantage-- at least at these "sane" speeds.
there's a lot of VBox experts out there i know, so if i've got my interpretation TOTALLY wrong, please speak up!<!-- / message -->
- 88-89 deg F
- approx 80% relative humidity
both cars were also on the same gas, the equivalent (roughly) of CA 91 octane, at best.
both cars are 100% stock.
bottom line seems to be: 60-130mph, the two cars are basically just as fast as each other, BUT ONLY IF:
1) the GT2 is already ON BOOST;
2) the GT2 driver doesn't flub a shift
critically, it seems that the GT2 is indeed faster, as the speeds rise, and its the PDK's silly shifting that keeps it in the game.
<TABLE class=ncode_imageresizer_warning id=ncode_imageresizer_warning_1 width=900><TBODY><TR><TD class=td1 width=20>
</TD><TD class=td2 unselectable="on">This image has been resized. Click this bar to view the full image. The original image is sized 1024x397 and weights 204KB.</TD></TR></TBODY></TABLE>from here you can see:
1) GT2 (blue line from bottom left corner to top right corner) is accelerating harder in each gear, but each time there's a shift, if falls behind again. in contrast, the PDK (orange line) acceleration is just seamless;
2) more importantly IMO, the GT2 is accelerating harder at the end. the slope of the PDK's acceleration curve is flattening out, whereas the GT2's is still looking pretty strong. FWIW, ave long-G's over the last 30mph or so of the run has the PDK is pulling about 0.28 G's, while the GT2 is pulling 0.31 G's.
finally, the PDK was actually going DOWNhill overall for this run (total elevation change was roughly -2 meters) while the GT2 was going UPhill, with a total elevation change of around +3 meters.
i know there's a way to normalize the numbers for the difference in level change, but someone will have to figure that one out for me
My take-away from all this is that in an ideal world, with a perfectly level surface, and with perfectly timed shifts, and with both cars on boost at the same time, YES the GT2 would be ahead.
but in the real world, the PDK driver holds the advantage-- at least at these "sane" speeds.
there's a lot of VBox experts out there i know, so if i've got my interpretation TOTALLY wrong, please speak up!<!-- / message -->
<!-- controls -->
"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."
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