Note: This is going to be a controversial topic. Please don't shoot the messenger. :D

A buddy of mine has a pretty well modded GT4. He has Dundon headers (he says they make power!), a tune, an IPD Plenum/GT3 Throttle Body, and maybe some other parts. His GT4 is really nice. Anyways, we get gas on the way to Cars and Coffee and shortly thereafter find ourselves with a very nice open stretch of road. We were probably going 55 to 65 mph, when we jump on it. My .1 GT3 pulls away pretty steadily. I would say a good 1/4 to 1/2 car length immediately opens up, and then it continues to widen. We did it a couple of times, and each time the result was the same. No big deal, as this is a GT3 vs GT4, although a seriously modded GT4.

When we get to C&C he tells me that he did a similar roll race against a friend in his new .2 Manual GT3. Those races resulted in a dead heat, with the GT3 starting to pull away at ridiculous speeds. We have a pretty good group of GT car owners, so this was a bit of a surprise. I guess we were thinking my .1 GT3 would possibly stay even with the GT4, but instead mine just walked away.

I think the reason is pretty clear. The difference is the PDK, with its fast shifts and extra gear/lower final drive versus the 6 speed manual. We could see a noticeable gap open every time the GT4 shifted. Subtle, but maybe a 1/4 car length jump each time. But the GT3 was pulling away each time from the start. The GT4 was quick, though. Those mods made a huge difference, and i am really impressed.

We will try to line up a .1 PDK vs .2 manual at Bandimere so we can see what the rest of the data looks like, but as of right now our assumption will be that 0-60 and 1/4 mile will favor the .1 PDK equipped GT3 over the .2 MT GT3. The .2 PDK should show an even bigger gap.

Btw, we also did a roll race with my .1 GT3 vs a .1 RS. It was essentially dead even. The RS was very low on fuel, while mine had a full tank. No passengers in either car. I think the GT3 would start to pull away at higher speeds due to less aero. That result wasn’t super surprising, but it was a data point.

At some point I am going to get headers. We’ll try to get the GT4, GT3 RS, and both GT3’s at the track to see how they compare, then do headers and try it again. My assumption is that with headers the .1 GT3 should be very competitive with the .2 PDK. But we’ll see.

Next time we will get video. Sorry, this was not planned. We just had a huge open stretch, no cars around, and well...you know. :D

I would love to see the results of a 991.1 pdk vs 991.2 pdk vs 991.2 manual test. It’s probably only a matter of time before a video appears on YouTube

You Tube

PDK only makes a huge difference if you don’t know how to operate the stick. 1:24.95s manual vs 1:24.66s PDK lap time in this test difference of less than 0.29 seconds: http://www.motortrend.com/cars/porsc...t-test-review/

“Don’t altitude” or not, I think it’s awesome how when you get an MT car you suck at it at first and learn to get better and better, eventually getting within a spitting distance of just having the computer drive for you once you’ve really mastered the car.

Lol SOME SAY his daily driver is a double-clutched manual with FOUR PEDALS.

We will definitely try to get the cars together at Bandimere to get really good data.

As i said, the GT4 wasn’t stock. But the key info here is modded GT4 races .2 GT3 MT and it is a dead heat. My .1 GT3 walked away from GT4 under similar conditions. And both guys know how the shift and have tons of track time. So no need to insult anyone.

I think power to weight is pretty close with the .2 GT3 and modded GT4. So not sure that result was surprising. My .1 GT3 walking away from the GT4 was. And again, both drivers know what they are doing.

Even from the jump my GT3 pulled away, so no shifting was even involved for the first 1/2 car length. Again, both guys know how to drive. My take is the gearing of the PDK (and 7 gears to 6) was the real difference here. I was probably in a lower gear ratio at every speed. Again, i don’t think these findings are controversial. Ultimately, a .1 GT3 with PDK is going to walk away from the .2 GT3 with manual on track or on the street. The extra 25 HP from the .2 and improved torque curve will not be enough to mitigate the PDK with better gearing. But we will try to get all these cars on the dragstrip to put real meat to it.

Thanks! It was fun.

Also, Motor Trend tested the .1 GT3 and got a 0-60 time of 3.1 seconds. The .2 manual GT3 is rated at 3.5 seconds 0-60. Why would this be surprising that the .1 GT3 is faster than the manual .2?

There are a few things mixed up here:

• US mags test 0-60 from a small roll
• You are comparing tested Vs. rated
• 0-60 performance for PDK is mostly about the launch, which is not relevant from a roll

If we talk about rated, both are rated at 3.5 seconds 0-60. So you would not expect the .2 manual to be quicker. Also, 7 gears to 6 shoukd be an advantage. And finally, we are not talking about “on paper.” These are actual results. Don’t shoot the messenger!

I think time will prove that statement quite inaccurate, and quite a stretch from thin data. Porsche quotes identical 100-200 kph times for the PDK and manual in the .2, and they state they are very even in their own roll-on testing. Either Porsche’s times are incorrect or the .1’s going to get dropped from a roll through that speed range.

Keep in mind that in addition to the 25 hp the .2 manual gets a weight advantage and lower frictional losses through the gearbox. That’s a 5.3% power advantage, 1.2% weight advantage and ~1% more power making it to the ground due too lower driveline losses. The latter two are likely what allow the manual to run with the PDK from a roll in Porsche’s testing despite both the slower shifting and gearing disadvantage. I suspect as we get more broken in cars into owners hands we’ll get plenty of .1 vs .2 runs to compare that will disprove your assertion above. The .1 will pull on the launch due to launch control, but how often are you launching?