SanDiegoDavid

I noticed that as well, very familiar.
My friends think I'm crazy, they are tired of hearing about this car until they go on a ride. Went out Saturday with a buddy who has an M3 driving and he was overwhelmed by the sound of the GT3. His wife now hates me!

Macca

Yeah. Im grinning alot. Every time the car goes to 9000 I cant help but smile.

Here are some answers from another thread where A few questions popped up. A friend drove the car to the track and it wasnt entered to drive so sat cold parked up all day till I decided to take it out on teh last session before the rain came down. Afterwards I realised the trunk was full of jack, 3 piece wrench etc so it was actually just as I would drive it on teh street with no tyre pressure adjustments. Fiend with 991 GT3 there that day doing laps told me first time out keep ESC on and sport auto with firm shocks and louder exhaust on. ESC slows you down so will come off next time. Manual change will require a bit more experience to use effectively as it will be slower initially but Im sure more fun. I use manual for spirited road drives (the next day we had a road trip back rouads with tarmac rally guys very fast and the car was supurb in manual). New engine had 300 miles on it before I took it on the track for one session. Now at 700 miles. I consider after the track session its run in!

Heres from other thread:

Hi Dan. Taking the GT3 on the track was a last minute thing as I was shaking down a new gearbox/ big brake/ wheel & tire combo on my 993 track car that day. I just jumped in it and went out with tyres at street setting full tank of gas and all my road driving gear on board even down to the precision instruments torque wrench in the trunk - probably 50lb of crap in the car lol!

My comments were based on tPM readings as you can see I have on permanent display while driving. Front tyres showed 39 psi by lap 6!

I use cecomp digital tyre gauge same as NASCAR teams immediately after coming in as can be seen here taken earlier on the same day with my 993....

When I next take the GT3 to the track for a full days sessions I'll be aiming to run 30 hot front and 32 rear hot. I have altered camber to -2.00 front and rear last week before driving the new engine....

mqandil

You are very welcome Sam. Yes we do have amazing back roads and amazing scenery. Love the Northwest.

Remember I went to school to UT at Austin, so I still have a soft spot for Texas.

Mark

mqandil

Macca that was a fantastic video. Thank you....The grin you had was printed permanently on your face, and I am sure for a very good reason. As you indicated these 9K rpm shifts are to die for. Considering the tires were still cold the traction was exceptional. However I have noticed you had a small steering correction couple of times in the video and it appears you had a little bit of understeer and you just unwounded the steering a bit, but not sure if that was the case.

I have not taken the car to the track yet but have done close to 1000 spirited miles on some fantastic back roads in the Northwest and honestly I have not used the auto mode and been shifting manually which is very addictive. I was worried about using the auto mode as it up shifts when you let off the gas, but that is during normal driving and perhaps on the track it may act differently. In my 911 4S and while using sport + it does not up shift until you reach the redline or you up shift manually which I like very much, but will try the auto mode during spirited driving and see how it does.
The plan is to hit the track this coming weekend and I can't wait to have that grin tattooed on my face. Again thanks for sharing the video... Mark

mqandil

Macca that was a fantastic video. Thank you....The grin you had was printed permanently on your face, and I am sure for a very good reason. As you indicated these 9K rpm shifts are to die for. Considering the tires were still cold the traction was exceptional. However I have noticed you had a small steering correction couple of times in the video and it appears you had a little bit of understeer and you just unwounded the steering a bit, but not sure if that was the case.

I have not taken the car to the track yet but have done close to 1000 spirited miles on some fantastic back roads in the Northwest and honestly I have not used the auto mode and been shifting manually which is very addictive. I was worried about using the auto mode as it up shifts when you let off the gas, but that is during normal driving and perhaps on the track it may act differently. In my 911 4S and while using sport + it does not up shift until you reach the redline or you up shift manually which I like very much, but will try the auto mode during spirited driving and see how it does.
The plan is to hit the track this coming weekend and I can't wait to have that grin tattooed on my face. Again thanks for sharing the video... Mark

Macca

Hi Mark. I added a steering correction in the sweeper after the fast straight as I braked quite late once past the 964 Cup car in Gulf livery. I came in a bit hot and heavy (236 kmph vmax and braking well after the 100m marker), so needed a correction there to apex the corner. It wasnt understeer related.

I had the shocks on firm although Im not sure this works best as the track has huge elevations as you can see.

Actually the cold tyre thing was not an issue. I went out on dead cold tyres at factory road pressures (29/33 psi). As I hadnt been using the GT3 on track and hadnt anticipated a drive the tyres heated up very quickly and by the time the footage you see was taken they were going off (40/40 psi). This did induce a little under steer on the laps with footage - I think there is one or two additional areas where I correct due to this.

Although I have slightly more aggressive geo on the GT3 (-2.00 f+r) I have not adjusted the front and rear sway bars. I think softening the front one notch should take care of the understeer on that track and with some proper tyre management (something Im religious in wit the 993 track car) theres another 1.0s a lap there for easy grabs. I believe there is a further second but its in the driver and the lines which may take a few more days at that track to squeeze out. Ive only been to that track once before (993) and the 19th was a very short 5 session (9 laps per session) day with only the one session in the GT3.

The car is a huge amount of fun on the track. Next time out softer front sway bar with lower initial tyre pressures and no ESC.

Of interest the PDK sport will hold the gears longer once it senses the driving style and operates quite differently than on the road. That being said the other 991 GT3 driver out there that day (I think this was his 3rd full day in the GT3) has far more experience with it than I and recommended for a sescond session out to take off the ESC (as its slows progress) and manually overide the sport auto with the flappy paddles in a couple of the tighter corners to be in a lower gear for exit. All makes sense now Ive done some exploratory laps. The fact that within half a dozen sessions a good driver can be eeking out consistent times equal to a factory 997 Cup car of a few years ago is mighty testament to who things have moved on with this new GT3!

Macca

Hi Mark. I added a steering correction in the sweeper after the fast straight as I braked quite late once past the 964 Cup car in Gulf livery. I came in a bit hot and heavy (236 kmph vmax and braking well after the 100m marker), so needed a correction there to apex the corner. It wasnt understeer related.

I had the shocks on firm although Im not sure this works best as the track has huge elevations as you can see.

Actually the cold tyre thing was not an issue. I went out on dead cold tyres at factory road pressures (29/33 psi). As I hadnt been using the GT3 on track and hadnt anticipated a drive the tyres heated up very quickly and by the time the footage you see was taken they were going off (40/40 psi). This did induce a little under steer on the laps with footage - I think there is one or two additional areas where I correct due to this.

Although I have slightly more aggressive geo on the GT3 (-2.00 f+r) I have not adjusted the front and rear sway bars. I think softening the front one notch should take care of the understeer on that track and with some proper tyre management (something Im religious in wit the 993 track car) theres another 1.0s a lap there for easy grabs. I believe there is a further second but its in the driver and the lines which may take a few more days at that track to squeeze out. Ive only been to that track once before (993) and the 19th was a very short 5 session (9 laps per session) day with only the one session in the GT3.

The car is a huge amount of fun on the track. Next time out softer front sway bar with lower initial tyre pressures and no ESC.

Of interest the PDK sport will hold the gears longer once it senses the driving style and operates quite differently than on the road. That being said the other 991 GT3 driver out there that day (I think this was his 3rd full day in the GT3) has far more experience with it than I and recommended for a sescond session out to take off the ESC (as its slows progress) and manually overide the sport auto with the flappy paddles in a couple of the tighter corners to be in a lower gear for exit. All makes sense now Ive done some exploratory laps. The fact that within half a dozen sessions a good driver can be eeking out consistent times equal to a factory 997 Cup car of a few years ago is mighty testament to who things have moved on with this new GT3!

mqandil

Thanks Macca for the valuable information. I think next Sunday which will be my first track day with this car I will do a little trail and error on the tires pressures but also the shock setting. I was planning to start with 4 psi below factory street sitting for cold pressure in attempt to stay close to 36 psi hot, and will adjust the pressures after few hot laps. This is the first time I use cup tires on the track and not sure if they get too greasy once they approach 40 psi like some of other track tires I have used in the past.

Portland International Raceway has couple of bumpy turns and probably is best to leave the shocks on the softer sitting. It seems the car has enough dampening on its softest sitting.

One question, what was the stock camber on your car from the factory. I am planning to check the alignment this week and would like to hear your opinion about the sitting you recommend for a balanced handling / tire wear. You mentioned -2 deg front & back. Are you going to stick with this setting.. Thanks again bud... Mark

Macca

Hi Mark. -4.0 psi cold start should work fine for the first session assuming track has some heat. Its a good starting point. Interestingly they tyres did become a bit greasy above 40 psi but actually the chassis and electronics (RWS?) collected up any movement very well and I set my fastest lap on tyres which were technically 4-6 psi higher than they should have been! I checked my pressures cold against my cecomp digital tyre pressure gauge and the TPM isnt far off accurate either (+/- 1 psi maybe a fraction more).

Ive attached my geo sheet below. You can see before and after. We have maxed out the front geo as far as it will go using the factory shocks/top mounts without adding spacers or AM lower coffin arms with adjusters. You can go a fraction more but will upset toe.

I have no experience with the geo on this car so cannot comment on my settings other than to say the car turns in more crisply on these settings on fast road driving like I did the day after the track. The factory settings (-1.30 front and rear) are conservative as the GT3 is primarily a road car. I like the -2.0 settings as they are a good balance between track handling and wear.

If you are starting out fresh Id use sport auto, standard shocks, lower tyre pressures (not too low first session out as easier to let them down end of each session to get them right) and sports exhaust (for aural pleasure!). You can manually over ride teh auto if you wish but things will start happening quickly as you push on so I wouldnt advise full manual for a first day out. Id leave ESC+TC for the first session then take it off and just leave TC in place.

mqandil

Thanks again Macca. Great info and advise. I will follow your recommendations and will report back my impressions next week. Thanks again. Mark

Dan39

Hi Macca, thanks for the comments as always. Curious if you took tire temperature readings with a pyrometer to get a numbers-based (rather than seat of the pants) view of how balanced your tire wear is and whether the car is still tending to understeer? The reason I ask is that the few other posters on the subject who have adjusted camber have added more to the rear, same with the 997 models, about 0.5 degrees. Sam has then gone on added rear roll stiffness and softened the front to boot! Maybe you could comment on your thinking here.

Macca

Hi Dan. The session was the last of the day and an afterthought (I had only 300 miles on the new engine and was never originally intending to take it out) so after coming into the pits I simply go on with packing up both cars (a job in itself) and never thought to check the tyre temps with my pyrometer sorry.

With 964RS/993RS & 964/993 Cup cars it is common practice to add more camber to the front than the rear. The front tyres are working hardest across their entire width and benefit most from this strategy. I had no idea that strategy is upside down for 997 and 991 GT3. It doesnt make much sense to me.

I have posted my geo on this board in three threads but yet to see a single other geo sheet from other owners so cannot comment if their changes have been made at the expense of toe settings. The way I see it everyone here has guessed a setting and are still learning the chassis dynamics so i doubt any real useful data exists yet by members here.

My geo settings were a guess like others. Porsche NZ provided my geo wizard the full factory settings for the 991 GT3 and some advice from the factory on how to static set up the rear camber. I asked him to take the front out as far as it can go without the need for spacers or after-market lower arms. He did this and changed the rear to a setting he felt suitable to work with the fronts. The fronts are approx 1/4-1/3 degree more negative (18 seconds) more negative than the rears. The limitation was the fronts - the factory top mounts have little adjustment left in them as Chuck Moreland will tell you.

After a few years experience changing geometry on the 993 track car I am not of the opinion you should introduce large variances to a new and relatively unknown/informed platform all in one go. My approach would be to move the front camber out slowly, tidy the rear up then play with the sway bars. Personally I didnt experience enough understeer to warrant stiffening the rear AND softening the front sway bar (Ive experimented with these on the 993 and they can have a pronounced affect even more so when used together in this manner). That being said I havent driven Sams car to compare.

My GT3 will be used for fast tarmac and track as well as general road driving so I dont want as uncompromising set up as I have with my 993. My next outing at the track will see me playing with the tyre temps between sessions to get a 30/34 psi F/R hot pressure and I will back the front sway bar off one notch (softer). I will try that for 3-4 sessions and see how I feel whilst checking the front tyre surface temps and see if I feel the need to compromise tyre longevity on the road by pushing the front out another half a degree. I think the rears are fine where they are.

Its a very capable chassis and isnt prone to understeer - infact its the least understeer ive experienced in any factory production 911 chassis I have owned (see my past in sig below). The risk of dialing too much of it out all in one go is oversteer and I want to play with overseer progressively with ESC off not all at once by over endowing the front end for grip.

there is no right or wrong settings this early in the game but hopefully with more time and experience form others on the board we can all benefit form their findings...remember straight out of the box on factory settings many journos like Chris Harris have set some impressive times at tracks like Angelsea in the UK etc.

SamFromTX

Great input Macca, as always. I am very interested in your grip and tire wear info with your setup once you drive the car at your 10/10th so please be sure to report back on those.
In regards to manual override in certain corners, that is very true but I found out it can be minimized if one is able to maintain 50% throttle, where it will hold that gear for longer instead of prematurely upshifting. Obviously not always possible. The pattern is almost 100% predictable so you get to learn which corners will get short shifted.

Dan39

No, I didn't mean to imply anything has changed - I meant more negative camber on the front, less negative camber on the rear. Sorry for the confusion!

I think Sam reported this being balanced for him, in his experience so far, along with the rollbar adjustments:

F - 3.0
R - 2.5

Will be very interested in hearing further reports from your testing. Thx again.

YOCOHO

Awesome video's I can't wait for mine.
Question is your car all stock - tires, seats and no roll-bar?
I was told by a dealer Porsche does not recommend running slicks have you heard that? I think Hoosiers are ok what do you think?

Enjoy