I'm curious too...I always thought you'd want a little toe in on the rear for stability.

 

But even the manual says +10' toe in per rear wheel and that's about 2mm per side. I'm running slightly less.

I never heard a 911 running zero toe in the rear.

My car touches in the rear on top of the tire against the "roof" of the wheel well, not on the outside where rolling is suggested by Porsche.

You seem very well guided and I cant go to Joey on the East coast..

 

BBI should be done with the car today but here are the details of the set-up...

Stiffer Swift springs front and back
-3.2 camber front and -2.7 camber rear
Slight toe in for the rear and none in the front
advised to try the sway bars both at medium to start
Front and rear was lowered by 1/2 inch (front is 27.25 inches and rear is 27.75 inches)
Added sway bar links to corner balance the car
Bremebo slotted rotors, RT10 pads, and Endless fluid
BBI side muffler delete pipes

I'll post a few pictures later on tonight.

 

Why so much camber with stiffer springs confuses me.

What tires?

Help the left coasters out buddy!

 

I need camber as I run flat out at all times. No, I spoke with the suspension guy at BBI and he says that the front doesn't have good suspension geometry. Basically the front creates positive camber when turns due to the caster limitation. One of the RSs that he set up which runs 80% of the miles on track is at -4 camber front and -3 rear. I'll see how tire wear looks and adjust from there. Car came with Cup2s which I have about 1,500 street miles on. When you coming out West again?

 

USC,

Your set up sounds just about identical to mine, which makes sense since Joey use to be co-owner of BBI. He described it as Stage I.

 

I think BBI's suspension guy and Joey are both good and have similar opinions on how these GT cars should be set up....they like them low with some camber.

 

As always it interesting to see a range of different philosophies to setting up an RS to go fast on track.

The RS has its own unique challenges. Quite a different car to set up from the 991 GT3. Obviously height and rake will make a difference to down-force an attitude, but potentially at the expensive of practicality on the street and rubbing under compression on the track.

Id really love to speak German and spend a day at a Porsche Production Car round on a German track to learn better how guys who are racing these road cars for honors are setting up their 991 GT3+RS.

My experience with my GT3 to date seems quite counter to what alot of folk are doing with their cars on track in USA. Perhaps I just wasn’t as quick a driver to start with! Certainly guys like Peter and Kobalt, Joe and many other GT3+RS owners on this board had a lot more experience with track work and GT cars going into this compared to me. Ive got pretty quick now, but I guess it’s all relative.

 

Here is a cut and paste from an email I sent to a fellow NZ 991 GT3 owner who has done a couple of track days and was asking what he do to make his car faster on the track.

In my first email to him I covered off my experiences of camber vs heat cycle (MPSC2), getting the tyre temps right etc.

Humour me for a moment. I know its a long email. I still believe (for me, on my tracks) that seat time, learning the platform and driving closer to my/cars limits has made the biggest improvements to my track times.

Personally on the 991 GT3 all I have found camber good for is tyre longevity. We run 15 min sessions 6-7 times a day over here, so my tyres have reached cycles before the front shoulders are toast with the -2.0F+R settings I currently use.

Massive -ve camber otherwise in my experience introduced benefits and compromises to a lap (even more so on the road) and doesn't result in a particularly faster time. Likewise, non OEM pads, rotors etc are all about $cost and longevity choices. The brakes work just fine stock (though SRF or similar fluid is always a wise investment).

The only non hp changes to the 991 GT3 I think one can make for ultimately faster lap times assuming tyre condition and temps are good are aero (Cup slitter, Crawford wing combined with rake settings).

All my points assume factory 20" MPSC2 tires....

My email is below. I can to the this revelation after talking with last years Le Mans winning Racer, a young Kiwi who was in NZ in January for our Festival of Speed that I was a competitor. He is a young Kiwi guy and had just been in the country last Nov running a client day for Porsche where he had piloted a stock 991 GT3 around the track in quite an eye watering time (1.5s better than my PB on the short track and over 2s quicker on the long track). His views on the car were simple. Out of the box it was a great car, you just have to learn to push it harder, it can take more than you think and that if you want to go any quicker buy the next model up! Very frank words. His advice, if you can afford the tyres and the brakes dont mess with it......

 

And the email I refer to.

This isnt intended to be anything more than another point of view. I understand the RS has different set up challenges just as the GT4 does. The GT3 to be honest is pretty well set up out of the box compared to the others and I can just get through 30 heat cycles on my tyres before the shoulder wear through the fronts using the factory -1.5F+R geometry (I run -2.00 currently for durability due to a long 4000 mile track tour earlier in the year when I last used the car):


“I agree it’s a scalpel, and indeed its relatively easy to get 85% out of the car. What the last 2+ years on track with the 991 GT3 has taught me is that getting the last 10-15% out of the car is more of a challenge. The good news is that the car performs very well “on the limit” and has a much larger margin of error than say my older track prepped car like a 994 or 964.

The best example (and reason) I can show you that illustrates the difference between driving the car at 85% and 95% is in the two youtube clips below.

In July 2014 I was at the HD track with both cars and after a bit of peer pressure took the GT3 out for a single maiden session. I had never driven the car on the track before and had only driven the car 3500km in Europe prior to it going to HD that day.

In that session the tyres/brakes etc went from stone cold to way too hot but I managed to run off a series of 14s with a best lap of 1.14.01. I was amazed at the consistency I could achieve and quite intimidated by the Vmax compared to my track 993 (it doesn’t show much in the video as I didn’t back off anywhere LOL!). You can see the driving is smooth.

Roll on 2 years and 14 track days later to my 5th outing at HD with the GT3 and we are now over 2s quicker with even tighter consistency. The car is 100% stock (including the exhaust) as it was in July 2014.

So what has changed in 2 years, 15 track days and 2s per lap variance? The driving style! As you can see from the second video the car is more on edge. I’m having to make some corrective lock at least 2-3 times a lap and, although it’s not showing well on the video (sorry about the sound quality – microphone in wrong place), Im more aggressive with turn in and accelerator input on some corners (actually in T3&5 I often get the rear to slip a little though it doesn’t show on the video). This is a relatively tidy lap, at Taupo or Ruapuna I would use up far more of the track and get the car rotating much more frequently but HD has enough compression and camber on corners to not necessitate this.

What’s left on the table? Without any changes to the car probably the last 5%, 0.6s a lap at HD (say 1.11.00 best lap maybe a fraction above). Obviously a better driver will be quicker but Im talking for me.

What is required for the last 0.6s? Total commitment and confidence that I can turn the car in earlier (T1), more aggressive throttle application T10 (sweeper) and running the car harder into controlled over-steer (using some more opposite lock to correct) using the cars slip angles to rotate it quicker without loosing control or bogging down and loosing pace.

I think someone new to track work or the car would summarize buy saying “bigger *****”, but in reality it’s about knowing how the car will operate with slip angles and how to control it when its over-steering. Also some playing with sway bars would help and as always a cool morning and fresh tyres are critical to hp and grip. I will say the risks of a mistake will become much higher in this last 5%, but if you build into this over 5-6 track says you will learn how the car handles on the limit and mitigate that somewhat.

This is why I don’t believe the 991 GT3 really needs any changes to go faster unless you are:

A). already running low/mid 1.11s (at HD by way of example) with traffic dependent consistency or
B). have already reached a point where you either not getting any quicker (natural talent bar) or are not comfortable to run the last 5%.
C). Going broke replacing MPSC2 every 4 track days!



The car is plenty good out of the box IMO. A little more negative camber helps with front tyre durability and you can play with the sway bar to dial out a bit of corner entry under-steer if you need it. Otherwise the single biggest factors to going quick in the 991 GT3 are natural talent (lucky for some), followed by seat time. Of course this assumes the track is dry, tyres are not heat cycled out and you are keeping the hot pressure in range during the sessions…"

 

The kid is wicked quick but let's not forget the hair; has to be the best the paddock has seen in decades.
.

 

Nizer. Close. Thats Brendan Hartley another young Kiwi talent who won WEC and he was there too. Lovely bloke. Just bought himself a 991 GT3 as personal car. The guy Im talking about was Bamber. He was part if the 2015 LeMans winning driver team, currently hes racing RSRs.

 

Ah yes. No shortage of talent in the Porsche factory squad...

 

What did you do for center muffler?

 

Center muffler staying on.