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Planet9 Test Drive the new 991

GT4

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Porsche to Unleash new 991 in Frankfurt - We Drive It!: As some of you may recall a couple of months ago I was given the opportunity to drive a new 911, known by the internal designation as the 991. I was also asked not to post my experience on this site until the official embargo date had passed. Well it seems with the release of the official 991 images today that the embargo must have passed (I was supposed to receive follow up email but did not) so I thought it was time to share the experience.

First, if you are looking for more pictures of the 991 check out the topic thread here: Official 991 Pics! those will give you a much better view of the car than what I had. Why is that you ask? The car I was allowed to drive was missing several body panels (on purpose) because it was a suspension test mule of some sort. It also lacked a finished interior but had what I would guess was 2/3rds of the final bits based on the images I've seen. My drive was to be all about the handling and balance of the car. Did Porsche want the opinion of someone used to driving a mid-engine car on the balance of the new 911? I don't know but the representatives there were interested in my feedback.

Let's start with the testing grounds. It was an industrial complex in what I believe was New Jersey (I can never tell when I've gone from one state to the next in the northeast, the states are geographically too small) There Porsche has some warehouses of some sort and plenty of parking lot space surrounding them for testing. It didn't appear to be the nicest neighborhood, in fact I didn't see many other humans as the location was something more out of the scene of a Mad Maxx movie than a glitzy race track or some other typical test venue. This wasn't a typical test though. Porsche had set up what amounted to a mini auto cross course with cones as well as some handling tests (friction circle & slalom) and a braking zone.

Although Porsche states that the car is only 10cm long, it looked longer to me, again, it was missing body panels so that could account for part of the "largeness" as it appeared to me. The interior seemed more roomy other than the odd footwell indentations, of course I'm used to a smaller Cayman cabin anyway, but it felt bigger inside too. I fired up the flat 6 which I'm told had more HP and torque on tap than before, final figures were still TBD when I tested the car although some figures have since circulated. The sound was not all that different from the 997 or even Gen 2 Caymans in terms of engine noise although again it was a little hard to judge what the final sound might be like given the missing parts of this test mule. This was to be all about driving so time to drive. I was really hoping for the new 7 speed manual because I wanted to see if it heel-toed for me or in essence rev matched, but this car had a PDK. I was asked to leave it in normal for our first run through the cones and I did so. I didn't push the car overly hard since it was my first time out and I wanted to get a feel for how it would respond. The steering was definitely different in this car than vs. my Cayman, at low speeds it almost seemed a little numb or vague as if dampened in some way, but as I started carving up corners it came alive and was very responsive and I had no complaints. I don't know if this was due to the weight of the car or the changed steering rack or both, it wasn't bad, just different. Once I got the hang of the feel I started to press harder. We stopped and switched into sport plus mode (my favorite in PDK) and bam bam bam we were knocking through the gears as we ran the course.


porsche_911_991_0_423.jpg


I think the longer wheel base helps the 911 in that whatever changes were made seems to make the car more stable, I never felt like the rear end was going to step out and of course with the big fat tires out back I was able to power my way out of tight turns. In all my "lap" times improved the more I drove and being in sport plus mode. If you get a PDK you really have to get sport plus. Next up was the slalom. The slalom is an area where the Cayman typically chews up the competition, one of the early magazine tests back in 2006 had the Cayman setting records in the slalom. Not that the 997 was a slouch, but it couldn't match the tossibility of the Cayman. Well let me clear it up right now, the Cayman in my opinion is still king of tossibility in the slalom but the new 991 appears to close the gap, whether it was the wider track, longer wheel base or grippy tires, the 991 did a great job through the slalom, it was only at the very limits did the weight in the rear start to "rear" its ugly head and make itself felt, but before that if you were blindfolded you might not know if you were driving a mid engine car or a rear engine car. Where I thought the 991 really shined was in the friction circle, something I've always found harder to do in a 997 than a Cayman, but I'd say that the wet friction circle test we ran found me keeping the car going around the circle with more ease that I ever could with a prior 997. Did I still spin out at times? Yes. Was it fun? Yes!

Once again, for me, there was a noticeable improvement in the handling capabilities of this test mule vs. the 997. The braking test was a no brainer but Porsche wanted to demonstrate the capabilities of their brakes under repeated abuse and I was happy to oblige. I'm pleased to report there were no problems in this area other than an occassional squeal once we got the brakes good and hot. The car was rock steady under hard braking the back end did not wander around and neither did the front (I was in a 997 turbo one time that really wandered in the front under heavy braking). I suspect a longer wheelbase helps in that regard as well.

In all I came away pleased with what I drove and the 991 appears to be an improvement over the 997 in the handling department and that's what our tests were focused on. Of course I was asked "So does it handle better than your Cayman?" to which I answered "My Cayman? No, not my Cayman, but a stock Cayman I'd say it's pretty darn close." That's really the summation right there, Porsche has improved the 911 just enough that the big differences in handling on the track vs. a Cayman are going to come down to the driver skill level as both cars are very capable in the handling department.

Is the Cayman still superior in that regard? I think so, but it really comes down to what you are doing in the handling department, if you are doing a lot of slaloms and transitioning left and right a lot then yes the Cayman still has better balance. If you dive bombing corners and powering out on the track the new 911 should be able to do that with more aplumb than ever before.

Were there some negatives? A few, but again I didn't drive a final production car so most of the negatives had to do with interior items, noise levels, visibility, etc. that were compromised in some way in this test vehicle. I do think the steering will take some getting used to at lower commuter speeds, I just didn't feel like if I wanted to make a sudden rapid lane change at 60mph that the car would respond as quickly as it did in the past but I could be wrong.

I'm also used to how responsive my car is so maybe people can take that criticism with a grain of salt. Size was still an issue for me, the 911 is becoming a big car, I wouldn't want to put this on stage next to a 1964 model! Fortunately Porsche has worked to keep weight down.

Final figures were not shared with me but I was told it would be close to 997 figures despite the growth in the car. That's good to hear, certainly when we see other "sports" cars routinely going over the 3,500lb mark these days. I was also a little surprised that the back seats weren't markedly more useable given the growth in size, but maybe that's not a bad thing unless you had a couple of kids you wanted to stick back there and you were concerned about them outgrowing the back seats in a couple of years.


I'd like to thank the individuals at Porsche who made this test drive possible and recommend that our members check a new 991 out at their local dealerships later this year. If Porsche made this kind of improvement in the 991 it should be very interesting to see how the new 981 shapes up, I hope to test drive one of those soon!

TBD - Torque Biasing Differential
With an ordinary open differential, a lot of precious power is wasted during wheel spin under acceleration. This happens because the open differential shifts power to the wheel with less grip, along the path of least resistance. The torque capacity of the TBD/ATB unit is increased or decreased by varying the helix and pressure angles of the gear teeth. The operation is automatic and the unit is a direct replacement with the stock differential. There are no clutch plates as in more conventional limited-slip designs.

The Torque Biasing Differential or A.T.B., however, does just the opposite. It senses which wheel has better grip, and biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel. In drag-race style, straight-line acceleration runs, this results in a close to ideal 50/50 power split to both drive wheels, resulting in essentially twice the grip of an ordinary differential.

911_143.jpg


PDK - Porsche Doppelkupplung
(FAQ in Process)

Derived from motorsport, PDK, available for the 911 Turbo for the first time, achieves one thing above all else: it provides the perfect balance between uncompromisingly dynamic performance and exceptional levels of comfort. It's purely about point of view. The driver's especially.

The optional PDK with both manual and automatic modes enables extremely fast gear changes with no interruption in the power flow. For improved acceleration and significantly lower fuel consumption – without having to dispense with the advantages of an automatic.

The driver experiences a sportier, even more dynamic drive with more agility. Depending on driving style, gear changes range from exceptionally comfortable to exceptionally sporty.

Manual gear changes are performed using the PDK's ergonomically designed gear lever or the switches on the steering wheel: nudge forwards to change up, pull back to change down. The logic behind the optional three-spoke sports steering wheel with gearshift paddles comes from motorsport: pull to the right to shift up, pull to the left to shift down.

PDK has been specially tuned to the characteristics of the new 911 Turbo models. It has seven gears at its disposal. Gears 1 to 6 have a sports ratio, with the top speed being reached in 6th gear. The 7th gear has a long ratio and helps to reduce fuel consumption even further.

PDK is essentially two half-gearboxes in one and thus requires two clutches – designed as a double wet clutch transmission.

This double clutch provides an alternating, non positive connection between the two half-gearboxes and the engine by means of two separate input shafts (input shaft 1 is nested inside the hollowed-out input shaft 2).

The flow of power from the engine is only ever transmitted through one half-gearbox and one clutch at a time, while the next gear is preselected in the second half-gearbox. During a gear change, therefore, a conventional shift no longer takes place. Instead, one clutch simply opens and the other closes at the same time. Gear changes can therefore take place within milliseconds.

Clutch 1 controls the first half-gearbox, which contains the odd gears (1, 3, 5, 7) and reverse. Clutch 2 controls the second, which contains the even gears (2, 4, 6).

The optional Sport Chrono Package Turbo with dynamic engine mount system provides PDK with two additional functions, 'Launch Control' and 'motorsport-derived gearshift strategy'.

PDK – sporty, comfortable and efficient. Characteristics that have been given some thought elsewhere too: in the specification for the new 911 Turbo models.

http://www.planet-9.com/news-items/60612-driving-new-911-991-a.html
 
"Porsche states that the car is only 10cm long"

so it doesn't sound very big to me. :grin:
 
The new 991 will be 56mm longer, 65mm wider and 11mm lower than the 997.
 
But this isn't on a like for like basis though, the reviewer is a Cayman driver,

Will be interesting to see it on a 997 vs 991 review, (although we can probably guess that it will only get 2 stars from Total911 until the GT3/RS versions come out)

Someone posted yesterday that it's now become a GT, and I suppose that's a reasonable comment, but it's the market and price range that they need to go for perhaps, Porsche want the Bentley/Aston drivers to buy a Porsche so they need to offer something that will attract them,

Anyway, we'll see, I wonder if Exeter will give me one as a courtesy car at my next major service :?:
 
It's 50kgs lighter than 997 due to ally body and chassis (in part).
 
Andyuk911 said:
peters said:
"this has become a big car"

Sad news.

Size is not an issue .. weight is .... :judge:

It is if the biggest you can fit in a garage is a 996 (as in my case. My 964 was much easier.). Every water cooled 911 can be considered large.
 
Andyuk911 said:
peters said:
"this has become a big car"

Sad news.

Size is not an issue .. weight is .... :judge:

Both are issues IMO. The lighter the better, and the closer the weight is to the centre of the vehicle the better for changing direction. If the car is longer there is more weight away from the centre of the car, particularly if you do something dumb like stick the engine behind the back wheels.

MC
 
What matters is how the thing handles. A bigger car with a slightly longer wheel base may not be an issue.

If you recall the UR-Quattro's that Rohl drove. Two variants were run. The LWB and the SWB. Most drivers actually thought the LWB car was easier to drive and handled better in most conditions. The SWB quattro was a nervous beast but under certain circumstances and when driven to near it's limit, it just had the edge on the LWB URQ's.

I believe that what Porsche has done is to make the the 911 more easier to drive for joe public, by extending the wheel base and offsetting with a weight saving. We know the engine has moved forward so the overall cars balance should also be better :thumb:

Actually I have few concerns about how it will go/handle(only the Audi derived electric power steering system really concerns me)
 
Which is why they attempted to place it further in-board (by cheating and sticking the rear wheels further back :puh: )
 
What might be interesting to measure one day is the distance from the centre of the rear wheel hub to the rear of the new car(minus the distance from the rear(overhang) to the engine mounts(this will also give the distance calc from the engine mount back to the hub centre). Then compare these three measurements with the 996/997.

This should tell us by how much % the true engine forward change is on the rear axle vs previous 911's
 
wizard993 said:
What might be interesting to measure one day is the distance from the centre of the rear wheel hub to the rear of the new car(minus the distance from the rear(overhang) to the engine mounts(this will also give the distance calc from the engine mount back to the hub centre). Then compare these three measurements with the 996/997.

This should tell us by how much % the true engine forward change is on the rear axle vs previous 911's

If you can wait until 1st March I'll let you know the measurments :thumb:
 
Rimmer said:
wizard993 said:
What might be interesting to measure one day is the distance from the centre of the rear wheel hub to the rear of the new car(minus the distance from the rear(overhang) to the engine mounts(this will also give the distance calc from the engine mount back to the hub centre). Then compare these three measurements with the 996/997.

This should tell us by how much % the true engine forward change is on the rear axle vs previous 911's

If you can wait until 1st March I'll let you know the measurments :thumb:

I may have bought an R8 by then if the 991 is a flop :lol:
 
"While the 911's basic design philosophy remains unchanged, its proportions have been tweaked to improve safety and stability, and to improve interior space, chiefly rear legroom. The wheelbase has been lengthened with the front and rear overhangs reduced to minimise the increase in overall length. At 4491mm long, 1873mm wide and 1299mm high, the new 991 will be 56mm longer, 65mm wider and 11m lower than the 997."
 

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