GT3 991.2 Press Reviews and Awards

[GT3T]

Let’s start with Autocar’s - Britain’s Best Driver’s Car 2017

Start with the contenders:
https://www.autocar.co.uk/car-news/new-cars/britai...

The final three:
https://www.autocar.co.uk/car-news/new-cars/britai...

The winner:
https://www.autocar.co.uk/car-news/new-cars/britai...

[browngt3]

I'm guessing it will be a similar line up for Evo. The GT3 should win this too but they may give it to the McLaren as they don't want yet another Porsche winning ECOTY!

[Taffy66]

Interesting that the GT3 which won Autocar's car of the year was a PDKS.In complete contrast the GT3 which didn't fair too well in this year's Motor Trend driver's car of the year was a manual..I suspect a large part of this is the E-diff on the PDKS can vary the torque to each rear wheel depending on speed and steering input.
Basically the aggressive LSD on the manual hinders the car on very tight low speed corners resulting in more understeer compared to the PDKS's E-diff. The aggressive diff on the manual is tuned to work better at less sharp high speed corners..The E-diff reacts better in all scenarios and all speeds.
The Motor Trend's manual GT3 was criticised for poor front end grip on the sharp low speed corners which is a result of the aggressive fixed diff of the manual.

[LaSource]

Think it should just need a geo adjustment (more rake and camber/toe adjustments at front) and driving style adjustment (more trail braking) to drive a 911 with a stronger diff and traditional chassis (no rws/e-diff stuff).

Older 996s have been working with this model for years without people complaining of 'understeer' - unless one is not used to driving an (analogue) 911 platform.

Maybe I'm wrong, but sounds like the manual car was driven by someone expecting it to drive like the other assisted cars.

[Porsche911R]

Correct the PDK cars drives its self, with e diffs, automatic , more rws angles and PTV.

The manual car you have to drive.

Depends if you want to win at track days or go out and drive for fun.

It’s a shame they voted an automatic Drivers car of the year :-(

[franki68]

Taffy66 said:

Interesting that the GT3 which won Autocar's car of the year was a PDKS.In complete contrast the GT3 which didn't fair too well in this year's Motor Trend driver's car of the year was a manual..I suspect a large part of this is the E-diff on the PDKS can vary the torque to each rear wheel depending on speed and steering input.
Basically the aggressive LSD on the manual hinders the car on very tight low speed corners resulting in more understeer compared to the PDKS's E-diff. The aggressive diff on the manual is tuned to work better at less sharp high speed corners..The E-diff reacts better in all scenarios and all speeds.
The Motor Trend's manual GT3 was criticised for poor front end grip on the sharp low speed corners which is a result of the aggressive fixed diff of the manual.

Motor trend have a coty to a Mercedes amg gt,this disqualifies them from being a reliable source;)

[franki68]

Porsche911R said:

Correct the PDK cars drives its self, with e diffs, automatic , more rws angles and PTV.

The manual car you have to drive.

Depends if you want to win at track days or go out and drive for fun.

It’s a shame they voted an automatic Drivers car of the year :-(

They made particular mention of the drivetrain as being one of the reasons the car was so good.
I’m sure a manual would have won as well,but here’s the thing you don’t have to cry over it because if you can get one you can choose what box you want.

[browngt3]

Porsche911R said:

Correct the PDK cars drives its self, with e diffs, automatic , more rws angles and PTV.

The manual car you have to drive.

Depends if you want to win at track days or go out and drive for fun.

It’s a shame they voted an automatic Drivers car of the year :-(

Agree with this. Autocar should have used a manual for something called Drivers car of the year. I was also mystified why Evo ran a comparison recently with the original 996 GT3 against a PDK 991.2

With all the media hype and expectation when we first heard there would be a manual it's disappointing so little coverage of it. Or maybe no press car available?

[isaldiri]

Taffy66 said:

Basically the aggressive LSD on the manual hinders the car on very tight low speed corners resulting in more understeer compared to the PDKS's E-diff. The aggressive diff on the manual is tuned to work better at less sharp high speed corners..The E-diff reacts better in all scenarios and all speeds.
The Motor Trend's manual GT3 was criticised for poor front end grip on the sharp low speed corners which is a result of the aggressive fixed diff of the manual.

What are the locking ratios on the diff? Porsche have progressively moved mechanical locking ratios lower for their road cars and there's nothing at all to suggest they have beefed up the manual .2gt3's diff ratios at all to make it 'aggressive' as you claim.

[MDL111]

franki68 said:

Porsche911R said:

Correct the PDK cars drives its self, with e diffs, automatic , more rws angles and PTV.

The manual car you have to drive.

Depends if you want to win at track days or go out and drive for fun.

It’s a shame they voted an automatic Drivers car of the year :-(

They made particular mention of the drivetrain as being one of the reasons the car was so good.
I’m sure a manual would have won as well,but here’s the thing you don’t have to cry over it because if you can get one you can choose what box you want.

Still having a hard time with the whole the drive train on a GT car is so great - it is certainly good, but Ferrari engines nonetheless seem more special to me be it 8 or 12 cylinder cars. Maybe the porsches are better/more reliable in racing but as a weekend car, I am having a hard time with this statement

[Double gauche]

isaldiri said:

Taffy66 said:

Basically the aggressive LSD on the manual hinders the car on very tight low speed corners resulting in more understeer compared to the PDKS's E-diff. The aggressive diff on the manual is tuned to work better at less sharp high speed corners..The E-diff reacts better in all scenarios and all speeds.
The Motor Trend's manual GT3 was criticised for poor front end grip on the sharp low speed corners which is a result of the aggressive fixed diff of the manual.

What are the locking ratios on the diff? Porsche have progressively moved mechanical locking ratios lower for their road cars and there's nothing at all to suggest they have beefed up the manual .2gt3's diff ratios at all to make it 'aggressive' as you claim.

There was a post on rennlist in this regard
I think they were saying the ratio has increased to allow better high speed corner neutral balance?
It was at the peak of my technical understanding but I think I got it the right way around

I was nailed on manual but am having real second thoughts. My car will be for Euro touring with 1 or 2 track days a year
it’s not lap time that will make it more enjoyable for me- at all - but the pdks sounds so capable it might just as enjoyable to experience that as mastering the challenge of hell and toeing etc..
chris Harris didn’t seem that bothered with pdk hooning around Anglesey ...

[isaldiri]

Double gauche said:

There was a post on rennlist in this regard
I think they were saying the ratio has increased to allow better high speed corner neutral balance?
It was at the peak of my technical understanding but I think I got it the right way around

I vaguely remember reading about that on rennlist but iirc there was only mention of it by a single poster and not a single verified document or parts catalogue showing that and the claim came from the gt3 having a more aggressive ratio than the R. Frankly I find that impossible to believe - the gearbox is identical after all so it stands to reason the mechanical diff would be transplated in as well. Also and more to the point, Porsche have since the 996 increasingly reduced the diff's effectiveness in favour of using the rear brakes and that process (ie using rear brakes ie PTV) has only intensified hugely in the 991 so there's nothing at all so far to suggest the .2 manual diff is a) any more aggressive or b) going to last any longer than the 7gt3 which isn't known for it's longevity.

Happy to be corrected but it would be considerable break of the current trend if that was the case.

[ras62]

copied from Rennlist

.2GT3: 30% on power, 37% on decel
911 R: 22% on power, 27% on decel

and for reference....

997 GT3: 28% on power, 40% on decel

[Taffy66]

ras62 said:

copied from Rennlist

.2GT3: 30% on power, 37% on decel
911 R: 22% on power, 27% on decel

and for reference....

997 GT3: 28% on power, 40% on decel

Thanks for that as i was halfway looking for it.Thats a hugely more aggressive diff and pretty much tallies with my post above..The R is set up for road driving and the manual GT3 is set up for maximum attack on a fast track..

[isaldiri]

ras62 said:

copied from Rennlist

.2GT3: 30% on power, 37% on decel
911 R: 22% on power, 27% on decel

and for reference....

997 GT3: 28% on power, 40% on decel

interesting that thanks. So it's more or less back to the levels of the 997 gt3 (which has a pretty ineffective diff and very much rear braked as OEM) but still a long way off the Cup car or 996 gt3 levels.

[LaSource]

ras62 said:

copied from Rennlist

.2GT3: 30% on power, 37% on decel
911 R: 22% on power, 27% on decel

and for reference....

997 GT3: 28% on power, 40% on decel

996 GT3 run 40 / 60 diffs. The factory plates are a little soft and hence when refreshed most people install motorsport plates. These are much harder wearing and allow for higher preloads.
Hence my point earlier that all the above diffs are relatively weak and rely on rear braking systems to augment the diff. So could see the small deltas between manual and pdk being that material.
The 997s (and later) also have more rear biased brakes anyway whereas the 996s are more heavily front biased so it is easier to load up the front axle with more rotation available from the rear diffed axle. Passive suspension helps too.

Edited by LaSource on Sunday 17th December 21:04

Edited by LaSource on Sunday 17th December 21:07

[isaldiri]

LaSource said:

The 997s (and later) also have more rear biased brakes anyway whereas the 996s are more heavily front biased so it is easier to load up the front axle with more rotation available from the rear diffed axle.

Not entirely convinced of that now

[AndrewD]

Has there been a decent driver review of the manual 991.2 GT3 yet, eg Harris?

[LaSource]

isaldiri said:

Not entirely convinced of that now

Intrigued to see how your mods have changed the car. We’ll have to await a suitable time and venue next year

[Cheib]

AndrewD said:

Has there been a decent driver review of the manual 991.2 GT3 yet, eg Harris?

Sadly not!