997/996 GT3 dynamics

997/996 GT3 dynamics

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Discussion

braddo

Original Poster:

10,399 posts

187 months

Thursday 24th January 2019
quotequote all
Riding on the coat-tails of a thread like this:
https://www.pistonheads.com/gassing/topic.asp?h=0&...

In the interests of perhaps more threads about driving and dynamic enjoyment, and fewer about the colour and style of the thread holding seats and dashboards together...

I thought it might be interesting to start a thread where people can talk about how the pre-991 GT3 cars make people feel - the kinds of handling traits they feel, or which they learn over time; how a GT3 feels the first time people drive one; how people might have to adapt driving styles compared to previous experiences in other cars or adapting to different setups of the very same car etc. How the steering feels through one's fingers. How that fantastic noise is coming from behind me rather than in front. biggrin

braddo

Original Poster:

10,399 posts

187 months

Thursday 24th January 2019
quotequote all
And so some bits of my experience after a few years of having a 997.1 GT3.

Understeer - having grown up hearing about 'lethal' lift-off oversteer of air-cooled 911s, I was very reticent about the idea of trail braking in a 911. I knew it from having an Elise but if it wasn't for reading Steve Rance's posts on here I would probably still be wondering how to make a GT3 quicker than a MX5 around a track! Even a little bit of trail on the road makes a positive difference, as cmoose mentions when he took v8ksn's GT3 for a spin.

On track however, the heaviest of trail braking into slow corners can't quite seem to quell the understeer. Softening the front ARB made a big difference for a lot of corners but ultimately, the understeer is still there, right up until the car does a slow pirouette... Is this the PASM effect?

Brakes - stock brakes seem to make a rumbling noise whenever you really press the pedal. RS29 Pagid pads are bloody amazing (and don't make that rumble). Braking on track days hard enough to feel a bit of ABS pulse and there isn't the slightest hint of smelly brakes after a session.

But is the ABS getting triggered because the diff isn't locking properly (thus the rear axle is unstable and triggering ABS)?

Drilled brake discs are annoying. At least once every track day I have to remove pad material from the holes to preserve fade resistance. I do it with a bit of metal coat hanger. biggrin

Bumpy roads - on bumpy B roads in France, the ride was jiggly until you simply went fast enough. On the standard PASM setting I thought the car coped ridiculously well with bumpy little deserted country roads as long you're doing more than the speed limit.

Steve Rance

5,435 posts

230 months

Friday 25th January 2019
quotequote all
Nice thread. Not that you were asking for a highlight of the differences dynamically but the two cars are mainly separated by the PASM of the 997 and the diff set up of the 997. Essentially the 996 has both passive diff and damper set up which - when the diff has not worn heavily - makes the 996 more predictable nearer the limit. The diff set up of the 997 has an electrical over ride system which cuts in via the rear brakes after the plates wear out - which they tend to do quite quickly. From that point on the diff is pretty much managed by the rear brakes. The PASM set up tends to increase resistance to a loaded damper so if you are trying to drop the nose down on a trail, the car is trying to counter this by increasing the damper resistance. This makes things a little tricky at the limit, as there are fundamental variables effecting the car's behavior that are beyond the driver's control. This also applies to the rear brakes playing a part in rotation at apex and stabilisation under braking. Basically you need to be on your game to thread a 997 through a lap at 10/10ths compared to the more predicable and benign (relatively) 996. In the 1000's of laps that ive driven in 996's I cannot remember ever having a spin in one that wasnt caused by a puncture or mechanical issue (2). To counter that, I've had several very close calls in 997's that had me thinking 'what the hell happened there?'. it took a while to work out what was causing it and even then, it was difficult to manage

All this makes it sound like the 997 is a much poorer car on the track which actually it isnt, it's just less predictable but it is possible to tune yourself into one but it's tricky. i'd be happier pounding around a circuit all day in a 996 that I would a 997

On the other hand, the pasm makes the 997 a more comfortable car to drive up to 8/10ths so for road driving it's often the prefered weapon of choice.

The great thing is that both cars car be pretty easily transformed into exactly what you want them to be with sensible bolt on upgrades. Stick some high end dampers on either and you have a transformation. For the 996, the valving on the new damper will transform the car's road behaviour to make it at least as comfortable as the 997's PASM system and will unlock even more track performance, further enhancing the car's tactile nature. For the 997, new dampers will offer the same comfort on the road as the PASM system and will transform the cars track behaviour to make it as tactile and predictable as the 996 but a little quicker as the 997 shared the same underpinnings as the 996RS. Finally a diff upgrade to a cup/guards set up will tighten everything up nicely for the 996 and wont need looking at for several years. On the 997, the same upgrade will bring even more benefits as it will make the car far more predictable near and at the limit. So pretty much the same modifications will greatly improve both cars bringing out thier true potential. When set up like this, I find it difficult to choose the better car. Possibly the 997 as it has the 6RS underpinnings and a stronger engine - although I still prefer the 3.6 over the 3.8 so for me id prefer a Gen 1 car.

They really do represent a peak moment in time if you are looking for an involving and rewarding driving tool. Of all the racing drivers that I most respect, almost all without exception will put the 996/7 GT3 in the catagory of the very best driver's cars ever built.

Hopefully, prices will soon fall to a level where they are once again seen out in great numbers being used as Porsche intended. These cars are not about stiching, contrasting leather or other irrelivant options, they are simply about delivering a pure driving experience. Amen to that

EGTE

996 posts

181 months

Friday 25th January 2019
quotequote all
Amen.

D.no

706 posts

211 months

Friday 25th January 2019
quotequote all
braddo said:
On track however, the heaviest of trail braking into slow corners can't quite seem to quell the understeer. Softening the front ARB made a big difference for a lot of corners but ultimately, the understeer is still there, right up until the car does a slow pirouette... Is this the PASM effect?
How do you have the rear ARB set up?
Tyres?
Geo?

It's too early for me to feed back on ultimate on-limit handling traits as I haven't managed to drive my car on roads above 8 degrees Celsius yet (running Cup 2's) - never mind the track. I have noticed understeer creeping in where I don't think I would have experienced it in my 7.2 C2S (slow-speed, part throttle mid corner) but I put this down to not being able to get enough heat into the front tyres to make use of the more aggressive neg camber inherent on this car.

No doubt I'll uncover more of it's dynamic nature as the road surfaces improve, and commitment levels increase.

What I have learnt is that I absolutely love the character that percolates into every aspect of the driving experience at any speed- it somehow feels authentic, in a manner which is lacking in many other cars. I love the directness - the immediacy of reaction to given inputs. I love the ride (no worse than my sport-PASM equipped C2S), and the feeling of engineering integrity, and the reach of the ratios, and that engine. That engine..

The steering weight, the feel through the rim, and it's ratio is just right. The gear lever (after a good 15 minute warm up) feels like it's actually connected to a piece of heavy machinery, rather than it's other end waving around forlornly in a bucket of thick porridge slung beneath the car. The brake pedal pressure and resistance, and it's spacing to the throttle pedal are perfect for heel and toe-ing. It's an intuitive, well engineered, and hugely satisfying tool for enjoying the art of driving, at any speed.

I think the 997 GT3 is one of the best looking cars ever made. It's not too lardy, and it's size and proportions work well on our roads, as does it's performance, meaning there are more opportunities to exercise it's potential than there would be in wider, faster machinery.

I'm not hugely enamoured by leaving shards of front splitter all over Warwickshire, but that's the price of running it a tad lower than standard. Other than that I can't wait to grow old(er) with my GT3. After all, the older a 911 gets, the more stories it becomes part of, the more memories it will evoke, and the cooler it will get,

Just like us.

D.no

706 posts

211 months

Friday 25th January 2019
quotequote all
Steve Rance said:
Loads of brilliant stuff
Once out of warranty, the diff and suspension will be first on my list of changes.

TDT

4,910 posts

118 months

Friday 25th January 2019
quotequote all
Excellent thread.

D.no

706 posts

211 months

Friday 25th January 2019
quotequote all
Or maybe a 3-axis accelerometer and DSC box?

evodarren

428 posts

133 months

Friday 25th January 2019
quotequote all
D.no said:
Or maybe a 3-axis accelerometer and DSC box?
Hi Dean

I I tried the DSC box. It did seem to soften the suspension a small bit but wasn't to impressed. I had the car set up at Centre Gravity before I fitted the box and the car felt great. To me it fely like I could feel what the car was doing better than with the box.

evodarren

428 posts

133 months

Friday 25th January 2019
quotequote all
Steve Rance said:
Nice thread. Not that you were asking for a highlight of the differences dynamically but the two cars are mainly separated by the PASM of the 997 and the diff set up of the 997. Essentially the 996 has both passive diff and damper set up which - when the diff has not worn heavily - makes the 996 more predictable nearer the limit. The diff set up of the 997 has an electrical over ride system which cuts in via the rear brakes after the plates wear out - which they tend to do quite quickly. From that point on the diff is pretty much managed by the rear brakes. The PASM set up tends to increase resistance to a loaded damper so if you are trying to drop the nose down on a trail, the car is trying to counter this by increasing the damper resistance. This makes things a little tricky at the limit, as there are fundamental variables effecting the car's behavior that are beyond the driver's control. This also applies to the rear brakes playing a part in rotation at apex and stabilisation under braking. Basically you need to be on your game to thread a 997 through a lap at 10/10ths compared to the more predicable and benign (relatively) 996. In the 1000's of laps that ive driven in 996's I cannot remember ever having a spin in one that wasnt caused by a puncture or mechanical issue (2). To counter that, I've had several very close calls in 997's that had me thinking 'what the hell happened there?'. it took a while to work out what was causing it and even then, it was difficult to manage

All this makes it sound like the 997 is a much poorer car on the track which actually it isnt, it's just less predictable but it is possible to tune yourself into one but it's tricky. i'd be happier pounding around a circuit all day in a 996 that I would a 997

On the other hand, the pasm makes the 997 a more comfortable car to drive up to 8/10ths so for road driving it's often the prefered weapon of choice.

The great thing is that both cars car be pretty easily transformed into exactly what you want them to be with sensible bolt on upgrades. Stick some high end dampers on either and you have a transformation. For the 996, the valving on the new damper will transform the car's road behaviour to make it at least as comfortable as the 997's PASM system and will unlock even more track performance, further enhancing the car's tactile nature. For the 997, new dampers will offer the same comfort on the road as the PASM system and will transform the cars track behaviour to make it as tactile and predictable as the 996 but a little quicker as the 997 shared the same underpinnings as the 996RS. Finally a diff upgrade to a cup/guards set up will tighten everything up nicely for the 996 and wont need looking at for several years. On the 997, the same upgrade will bring even more benefits as it will make the car far more predictable near and at the limit. So pretty much the same modifications will greatly improve both cars bringing out thier true potential. When set up like this, I find it difficult to choose the better car. Possibly the 997 as it has the 6RS underpinnings and a stronger engine - although I still prefer the 3.6 over the 3.8 so for me id prefer a Gen 1 car.

They really do represent a peak moment in time if you are looking for an involving and rewarding driving tool. Of all the racing drivers that I most respect, almost all without exception will put the 996/7 GT3 in the catagory of the very best driver's cars ever built.

Hopefully, prices will soon fall to a level where they are once again seen out in great numbers being used as Porsche intended. These cars are not about stiching, contrasting leather or other irrelivant options, they are simply about delivering a pure driving experience. Amen to that
Hi Steve

Just wondered what the tell tale signs of the diff being worn on a 997.1 GT3

Digga

40,206 posts

282 months

Friday 25th January 2019
quotequote all
D.no said:
I think the 997 GT3 is one of the best looking cars ever made. It's not too lardy, and it's size and proportions work well on our roads, as does it's performance, meaning there are more opportunities to exercise it's potential than there would be in wider, faster machinery.
This is very personal and subjective, but I think the 997 GT is the pinnacle. The 996 GT3 is very, very pretty and dynamically, but to me it lacks a little of the visual drama of the 997 GT3.

D.no said:
I'm not hugely enamoured by leaving shards of front splitter all over Warwickshire...
I've got Staffordshire covered for you, as well as bits of North Wales. Still, new splitters are only £120.

D.no said:
I can't wait to grow old(er) with my GT3. After all, the older a 911 gets, the more stories it becomes part of, the more memories it will evoke, and the cooler it will get,

Just like us.
Totally and absolutely this. I did consider selling at one point, but it would have been a mistake and the plate I have is there to remind me this is a keeper:



For me too, it's too early to profess any real knowledge of the limit. I did a couple of trackdays last year at Oulton and the Nurburging, but did not get the car fully set up until the end of the year. I had PCCBs on and although they were superb, I was paranoid about wrecking them - they're now safely stashed and I have Alcons & Pagid pads to trash.

Cunno

511 posts

156 months

Friday 25th January 2019
quotequote all
evodarren said:
Hi Steve

Just wondered what the tell tale signs of the diff being worn on a 997.1 GT3
It’s a 997 GT3 is the biggest sign. The standard diff plates are useless if it’s not been upgrade it will be fubar.
Other signs are instability while braking hard and struggling to put power down coming out of sharp bends

Dr S

4,995 posts

225 months

Friday 25th January 2019
quotequote all
Steve Rance said:
They really do represent a peak moment in time if you are looking for an involving and rewarding driving tool. Of all the racing drivers that I most respect, almost all without exception will put the 996/7 GT3 in the catagory of the very best driver's cars ever built.

Hopefully, prices will soon fall to a level where they are once again seen out in great numbers being used as Porsche intended. These cars are not about stiching, contrasting leather or other irrelivant options, they are simply about delivering a pure driving experience. Amen to that
Definitively Amen to this! We need more such threads

Porsche911R

21,146 posts

264 months

Friday 25th January 2019
quotequote all
Steve Rance said:
Nice thread. Not that you were asking for a highlight of the differences dynamically but the two cars are mainly separated by the PASM of the 997 and the diff set up of the 997. Essentially the 996 has both passive diff and damper set up which - when the diff has not worn heavily - makes the 996 more predictable nearer the limit. The diff set up of the 997 has an electrical over ride system which cuts in via the rear brakes after the plates wear out - which they tend to do quite quickly. From that point on the diff is pretty much managed by the rear brakes. The PASM set up tends to increase resistance to a loaded damper so if you are trying to drop the nose down on a trail, the car is trying to counter this by increasing the damper resistance. This makes things a little tricky at the limit, as there are fundamental variables effecting the car's behavior that are beyond the driver's control. This also applies to the rear brakes playing a part in rotation at apex and stabilisation under braking. Basically you need to be on your game to thread a 997 through a lap at 10/10ths compared to the more predicable and benign (relatively) 996. In the 1000's of laps that ive driven in 996's I cannot remember ever having a spin in one that wasnt caused by a puncture or mechanical issue (2). To counter that, I've had several very close calls in 997's that had me thinking 'what the hell happened there?'. it took a while to work out what was causing it and even then, it was difficult to manage

And have I not been saying for 10 years that the 996 GT3 is easier to drive due to IT BEING MORE PREDICTABLE :-)

In fact I have lost count how many times I have said it :-) and lost every post I have ever said this. lol

o well people catch up, or I have to wait for you to confirm it lol then every one believes me, I just have to wait 10 years for my posts to become relevant.

Digga

40,206 posts

282 months

Friday 25th January 2019
quotequote all
Cunno said:
evodarren said:
Hi Steve

Just wondered what the tell tale signs of the diff being worn on a 997.1 GT3
It’s a 997 GT3 is the biggest sign. The standard diff plates are useless if it’s not been upgrade it will be fubar.
Other signs are instability while braking hard and struggling to put power down coming out of sharp bends
Sadly, Porsche have, apparently, now stopped making the Cup diff plates for the 997 GT3...

I am considering my options, but basically, what Steve Rance and Cunno say is also echoed by Mike at Sports & Classic who looks after my car.

evodarren

428 posts

133 months

Friday 25th January 2019
quotequote all
Ive had mine over 6 years now. Tried many different cars to compare if I replace it. None come anywhere near it. I know they are faster handle better, buy boy when you get it right in the bends it rewards like no other car. I went ou with a friend who owns a 488 spyder , 812 superfast and a McLaren 675lt . He was in his Mac on Cup2,s and mine is running normal pilot sport 2,s I know on a track the Mac is fabulous , but we went for a spin on some great B roads. It was very damp and cold the Mac couldn't get grip and was sliding under acceleration and braking. My GT3 just left him and was pulling a nice healthy gap over a 3-4 mile section. Dry road, I know it would have been different,. But the 997 GT3 has just enough power and dimension to use well on a country lane.

braddo

Original Poster:

10,399 posts

187 months

Friday 25th January 2019
quotequote all
D.no said:
How do you have the rear ARB set up?
Tyres?
Geo?
When I bought the car the ARBs were both on full stiff. The one change has been to soften the front bar to half-way (there are 5 holes I think). It really made a difference to how the front keys into the road, say on just a trailing throttle into a medium speed corner, whereas on full stiff it felt like you'd always need to be on the brakes a bit to get the nose to grip.

Tyres were originally road P-zero pirellis - they really don't have much grip but not sure it's in a nice way. Have been on Cup 2s for a while.

Geo is due a look - just factory settings I think. So much of my car's mileage is on motorway that I don't want to go aggressive, i.e. driving out of London to and from country roads, track days, family day trips etc... Plus a couple of continental trips).

One handling trait I have found intriguing - discovered at Coppice corner at Donington - being a long corner it felt like you're stuck with some understeer for a while on steady throttle, until you can get to the corner exit phase. I started getting braver and eventually found that full throttle could be applied way earlier and instead of increasing understeer, it killed the understeer! But only on full throttle.

It doesn't feel like a drift or a transition to oversteer, but it seemed to pivot the car slightly inwards enough that it puts the car on the line you want. It's how I imagine rear wheel steer might feel. It made me wonder if there is an element of passive RWS in the suspension. Or that my suspension is fked. laugh Whatever it is I like it!


Digga

40,206 posts

282 months

Friday 25th January 2019
quotequote all
braddo said:
One handling trait I have found intriguing - discovered at Coppice corner at Donington - being a long corner it felt like you're stuck with some understeer for a while on steady throttle, until you can get to the corner exit phase. I started getting braver and eventually found that full throttle could be applied way earlier and instead of increasing understeer, it killed the understeer! But only on full throttle.

It doesn't feel like a drift or a transition to oversteer, but it seemed to pivot the car slightly inwards enough that it puts the car on the line you want. It's how I imagine rear wheel steer might feel. It made me wonder if there is an element of passive RWS in the suspension. Or that my suspension is fked. laugh Whatever it is I like it!
Mine (prior to geo work - I've not been on track since) does feel similar. I think it's as if the car either want you to be trail-braking or accelerating, fairly positively, in order for the front to load or unload. In the wet, there is a limit to this, but it's relatively benign.

Cunno

511 posts

156 months

Friday 25th January 2019
quotequote all
evodarren said:
Hi Steve

Just wondered what the tell tale signs of the diff being worn on a 997.1 GT3
It’s a 997 GT3 is the biggest sign. The standard diff plates are useless if it’s not been upgrade it will be fubar.
Other signs are instability while braking hard and struggling to put power down coming out of sharp bends

Digga

40,206 posts

282 months

Friday 25th January 2019
quotequote all
Subjectively, I just don't like the interior of the 997; it somehow looks like a Honda to me. The 996 is ageing better in that regard.

Also, throw a 996 on BBS split rims into the discussion, and the exterior preference for the later car crumbles.



At which point, you have to acknowledge La Source has it right; you want both, although his garage is deficient because he doesn't have a Gen 1 997, just a Gen 2. First world problems. hehe