John's 991

I use my CS2 on the road and track, and personally think that to get the real sense of the car's capabilities, you need to drive it on the track. If I was going to use a 991 as a daily driver, I would get the base Carrera with PDK and no sport suspension.

Regarding driving the CS2 on track, as others have said it is very fast and handles very well. I have had the brakes fade at Laguna Seca, which is notoriously hard on brakes. I switched to Castrol brake fluid when I changed the pads at around 2,800 mile and that helps quite a bit. I will add stainless steel lines and try the Pagid pads when I change them next, as neither were available when I made the first change. I will also keep my eye open for additional ducting for the front brakes.

One of the things I love most about the car is the dual personality, where you can drive in comfort to the track, listening to the satelite radio, getting 27-29 miles to the gallon down the highway. Then with the push of the Sport Plus and raise the rear wing, you have an amazing track car. As a note, I get 9-10 mpg on the track.

Regarding what I don't like about the car on track is that at 100mph+ with the windows open (required at the track events here) there is a lot of buffeting, to the point it is distracting. The other thing is that the low fuel light goes on with 6 gallons left on in the tank, which is distracting. I suspect that there will be a fix for the buffeting problem at some point and the dealer confirms that the computer takes over the fuel calc at 6 gallons (the float is at the bottom of the tank at that point) and can be confused when the fuel is sloshing around.

In addition to the brakes, the tires fall into the "this is a fast street car not a race car" category. I will replace my Pirelli's with PSS after my next track event in a couple of weeks. I will also look for a set of 19" wheels with R compound tires. The Pirelli's have lost a lot of grip with the heat cycles, which is not surprising. But when they were in their prime, they had lots of stick.

In short, I recommend you take your car to the track, even if you only drive 7-8 tenths, as it is still a blast and much safer than 5-6 tenths on streets. You will have another level of appreciation of the capabilities of the car, and will likely learn some things that could help you in an emergency situation later on the street. I have seen no signs of fragility nor have I heard of any. Brakes, tires, fluids and the front splitter I consider consumables and will need replacement more often with track driving than street driving and part of the price of admission to a great activity.

STALKER99

Hopefully we can change them to the GT3 mirrors and that will help with the buffeting. Rather disappointed they did not properly address the issue during development.

jdsc

Thanks to Gary and everyone else on this post re: tracking the 991. As expected I got the detailed and full explanation as to the where and why of Porsche brakes. And it is much appreciated. This being my first Porsche I am definitely looking forward to getting on track to experience what it can do in a safe and sane environment. Having a few years of competition experience a long time ago, albeit all formula cars, I expect the adrenaline and competitive spirit will come to the surface pretty quickly and I'll be trying to find the car's and my limits sooner than I should. Nevertheless, being able to reliably push the car with confidence means having the confidence the car is going to stop at every corner, every lap, just as it did the last time around with little or no change.
So, stainless brake lines along with some decent fluid, probably Motul 660. Now I need to figure out about increasing the airflow to the brakes......
And, a +1 on the GT3 mirrors.

Manifold

Thanks all for the comments, especially Gary.

Though I haven't tracked a 991, I've driven several variants on the road many times, most recently yesterday (991S with PDK). I'll continue to say that it doesn't subjectively feel like a 911 anymore, but that's OK, it's its own thing, namely a beast. The handling is clearly a level above the 997, and the car is so fast that I really do wonder if there' any need to go beyond the S for track use; the GT3 will surely be incredible, but may also be too much, too fast (I'm an advanced DE driver and instructor, not a racer).

Regarding brake pads, I soon outgrew the stock pads in the Cayman R and had to move to track pads (PF08/06), which are far better on both track and street. IMO, track brake fluid is also a must for a car which will be tracked regularly, even for beginning DE drivers.

SB

I've been doing DEs for over a decade in various cars/brands, and for the last six years in a 997S. It is almost always the same simple formula:

1. Brake Fluid
I've always been using Motul highest temp available

2. Brake Pads
I've tried quite a few brands over the years (carboechs, porterfields, Pagids, among others), but by far my favorite is Pagid RS19 "Yellow" because of feel, durabilitiy, gentle rotor wear and kindness to your paing (some pad materials are caustic, especially when mixed with water). These pads were designed to last 24hr endurance races and will most likely outlast your rotors! And yes, if you're driving like you should on the race track, factory pads will ruin your rotors. Street pads are not designed to work at higher temps and will start to melt and will bond to the surface of the rotor, causing vibration (often wrongly called "warping"). You may not see these deposits on the rotor either.
Drilled rotors WILL develop small stress cracks over time and you will need to replace them even though the thickness is still within spec.
3. Brake ducts are a bonus and at very least add some life to pads and rotors. Pad wear is more rapid at higher temps, and the rotors will probably take longer to develop stress cracks. I've used GT3 brake ducts on my 997S. But it looks like 991S already has fairly big ducts from factory and actually look bigger than 997S gt3 ducts (if my memory serves me well).

4. Alignment. Max Castor, more camber via GT3 control arms (1.6 deg max on stock suspension components)
Again, alignment is one of those things that is a compromise. I think there are not much downside to higher castor, but camber and toe will definitely impact your tire life. You will need 2.5-3.5 deg of camber depending on a tire for optimal tire efficiency and longevity of the tire on the track, but at the expense of tire life during street driving. On my 997S, I've been running a fairly aggressive for a street car 2.6 front and 2.0 rear, and I think that tire wear on the street was not too bad.

5. Sticky tires:
I think that you definitely need a set of R compound rubber for the track. I've used Toyo R888s on street and track, rain or shine for a number of years (also used Yokes a032s and Pilot Cups before). While it is not as sticky as Michelin PS Cups, the fall off in grip is more progressive, they're decent in the wet, and they work cold or hot unlike the cups which are scary when cold.

That's it really. 997S was really well balanced out of factory, and I expect my 991S to be at least as well balanced. I think the risk of making a change for the worse with aftermarket suspension components is very high. For instance, a rennlister and a fast driver, lowered his 997S with Bilstein kit, but he felt that it made the car handle worse, so he ended up swapping it back out to stock suspension.

I also DO NOT subscribe to the theory of changing brake lines for several reasons. It is probably a good thing to do so on a vintage car, but new cars have lines that do not expand, especially on sports cars. So I think that there is simply no benefit to doing this. On the contrary, you may be introducing a risk of a brake failure. First, if for whatever reason there is a design flaw or manufacturing flaw on aftermarket brake line, you are likely to end up in big trouble. Also, there has been a case of the steel braiding puncturing the line itself.

Now, I have a dilemma with my 991S. Pagid pads are not out yet (as far as I know). GT3 control arms are not out yet. There is no optimal track tire sizes available....I know that there is an option if buying OZ Superleggeras in 19 and using Toyo R888s, but sizes are 235/295, and on top of that the overall tire diameters are about 1" shorter than stock. While this should put 4% more torque to the ground, it also will reduce ground clearance by 1/2" which is not something I can live with an already low 991S with SPASM. I think Pirelli Corsas on stock rims should work well, but I just can't bring myself up to caughing up $2300 on a set of track rubber which will only last one season. Suggestions welcome!

simsgw

And that, my grandfather used to say, is why we have horse races.

One addendum, Manifold and JDSC, besides the approach of using Motul 660: that other suggestion from the racing CDI in the adjoining region was to use enough ducting to get the operating temp down to the 500F range, then use a brake fluid rated for 525 or so that is less hygroscopic, and then alternate between the blue and gold variants at each flush to make it easier to see when you've gotten the older fill completely flushed.

I don't remember offhand the name he suggested, but someone will mention it I'm sure. Well-known and respected name.

I don't have evidence either way, SB, but my engineer's intuition is that your 997 would have had fewer problems if you reduced the stable operating temp by increased ducting. The GT3 ducts are cheaper and do improve flow so they increase the air mass over stock ducts, but GT2 ducts will provide much more flow and for a hundred apiece they're worthwhile.

No evidence, as I say, but improving the operating conditions imposed on a subsystem usually should precede beefing up the components used. I spoke of them in reverse order, but I did those mods all in the same shop visit because I felt the increased cooling was essential. I recommend it even with the 991 if you were seeing those problems with a 997.

Gary

chuckbdc

This thread is full of outstanding advice from people who have reported their experiences with considerable insight and care. It is particularly good in its focus on being able to slow and stop the car. The detail in this thread is wonderful, but let me offer some advice to new owners or first time trackers who might find it daunting sounding. DO IT!

One thing that could get lost on new 991 owners or those who have not been to the track in a 911, or are not planning to push or compete (even against themselves), but just want to experience their cars and learn about high speed driving: you can go to a PCA DE with your car just as it is, have a great time and learn way more than you thought there was to learn. Best, everything you learn about safety, awareness and the particulars of your car is applicable to the street. It is so good that if you do it in the rain, that is bonus points from a learning standpoint.

So if the advice seems extreme or the steps expensive, keep in mind that beginers are unlikely to reach the braking conditions described by some of the serious experienced drivers in this thread. In fact, experienced people can moderate their driving to avoid overheated brakes- or even to keep revs at break in levels, and still go faster and have more fun than you might imagine.

If you are naturally outstanding or naturally really bad, you may take months of normal wear out of your tires and brakes. More likely you will just wear stuff a little faster the first time. They are the inexpensive consumables of tracking.

Assuming some reasonable degree of rationality and responsibility your greatest risk is the experience of safe high speed driving in a 911. The feeling of extreme satisfaction is difficult to avoid. If it lasts more than four days, reread the thread and start assembling the components you have read about. Next time they will pay for themselves.

simsgw

Definitely. I'm sure the novice from Hell exists somewhere, but I've never seen anyone come close to the limits of their Porsche in their first year of doing Driver Education days. And we don't encourage it either. You learn techniques better when you can be sure the car is well within its capabilities.

As Chuck knows, I took my brand new 991 Cab to a track day because I had a teaching commitment, and I had a great time without ever violating the guidelines on break in.

In our region, we liken track days to a chance to drive that really fun road you know without the risk of some tourist coming around the next corner in a motorhome. That's how we teach too.

Gary

MayorAdamWest

I was out on the track this weekend, and the car was great. I've got PDK and PDCC, and the car was absolutely predictable, but never felt rear heavy. No brake fade either. The only change I made was adding Motul brake fluid.

chuck911

++1 Especially the rain part. Especially for the average new owner, best track driving experience you can get is on a wet track. Speeds are lower, which lessens all the load problems everyone's been talking about. The high speeds that can be psychologically intimidating in the dry are somewhat lower, which (if you can get over the fear of a wet track!) actually makes it easier to test your limits. Wet track experience helps in getting over the fear of driving in the rain. And because a lot of guys sit out the wet sessions (or skip likely wet days) there tends to be less traffic to contend with. So if by chance it happens to rain, get out there and count your blessings!

SB

I like the "...horse races" quote...


Still, I completely agree with you on cooling....at very least, it promotes longevity of components (pads, rotors, bearings/hubs, etc). I've seen brake pads/rotors after a track session in 1400 F range, and certainly every bit helps. Street pads just can't hold up to track/r tires type abuse, and if by some miracle they did, the wear rate will be alarmingly fast.
I actually just didn't think of GT2 brake ducts when I had my 997S, and probably would've bought those if I did. However, ground clearance would be something to consider as I've messed up even presumably smaller GT3 ducts due to clearance on driveways.

With that being said, my 997S didn't have any issues, or at least I don't consider stress cracks to be an issue but rather a "feature" of drilled rotors. I had similar experience with drilled rotors on my previous car too (E46 M3). As drilled rotors expand and contract with heat cycles, stress cracks start to appear with time, originating from drilled holes. This is not the case on non-drilled rotors though.

I would definitely be up for upgrading brake ducts on my 991, so add that to the to do list.

Manifold

If taking a stock Porsche to the track as a novice, I recommend having an experienced guy keep an eye on the brake pads, rotors, and tires to make sure nothing's wearing too rapidly, especially if there isn't a required daily tech inspection by qualified and diligent people. On some tracks, you can go through these things pretty quickly, especially with a fast car like a 991. Also keep an eye on your tire pressures - they can go up by 8 psi or more within a session and you'll likely need to drop your starting cold pressures.

Regarding tracking in the rain, IMO it's definitely worthwhile. I've never missed a session in the rain, and what you learn will help when driving on wet roads. But I recommend leaving PSM on, dialing back your speed substantially, and talking with instructors about proper techniques for driving on a wet track.

Manifold

With the Cayman R, I had a lot of cracking of the front rotors (drilled), so I eventually replaced them with Performance Friction floating rotors (no holes or slots, just dimples). The initial cost is high, but they last much longer, so I think they'll be less expensive in the long run.

simsgw

Definitely. In fact, some regions provide car control clinics where they hire a special truck to wet down part of the facility for training at slow speeds.

I just realized something else that will be misleading new owners of Porsche considering a track visit. All this dramatic talk of braking from 140 mph and boiling the brake fluid has nothing to do with your track day. I apologize for not explaining sooner how track days work.

Renting a track is relatively expensive, several thousand dollars at least. We combine our use of the facility and provide Driver Education sessions but also a Time Trial or Autocross segment. The distinction under the rules isn't important. What matters is that those drivers are competing. They gather points according to their best lap time and trophies are awarded at the end of the season. Those are the people to whom I was directing my advice about brake upgrades.

When you come for a Driver Education day as a new owner, we don't put you on the track at the same time as those drivers; we don't allow anyone to time your laps (even yourself); and you definitely won't be putting your car under any stress. Neither your car, nor yourself. The objective of a Driver Education day is to let you learn your car in a safe environment. You will go on the track with drivers likely to be driving about the same speed and we space you on the track so you're not close to other cars. When you do catch up to someone else, or someone comes up behind you, passing must be done with a "wave by" and only on specified parts of the track. Usually a long straight stretch. They pull over, slow, and let you pass.

Teaching how to do that safely, and how to enjoy a Porsche at higher speeds, is the role of an instructor who will ride along for you first half dozen days of Driver Education. Going faster is not the goal because it interferes with learning the techniques that will let you drive better. Driving better will let you go faster as well, but only if you decide you want to do that. The real purpose is to make you a better driver on the public roads as others have said.

When you feel ready, and your instructor agrees, you will be approved for driving without an instructor aboard. If you decide it would be fun to try for fast times, and even possibly compete in autocross or time trials, your instructor will add some other driving techniques to your lessons, and when you've absorbed those a Solo DE/TT permit will be issued by your Chief Driving Instructor. (It applies nationally, but the CDI for your region is responsible for approving you.)

After that, when you come to track events, you can request to run in a faster group of drivers. Most regions run four groups at each track day. The green group is for novices. The blue group is for faster drivers, but usually includes experienced novices who have done several track days and are approved to drive alone after a check-out by an instructor in the first sessions of the day. The top two groups are usually reserved for drivers with a permit, although someone who is technically a novice but has a racing background might be put in the second-fastest group to reduce the amount of passing being done.

We reserve the top group for instructors and competitors. Regions vary in their emphasis. Some have a lot of competition drivers and they will often run five groups to be able to separate even these highly experienced drivers into two groups so the 914's won't be distracted trying to stay out of the way of Turbos.

It is the responsibility of the Chief Driving Instructor in each region to ensure that drivers are paired with compatible (and congenial) instructors and that assignments to run groups achieve what I've described: safe and entertaining day for each level of experience.

I'm happy to talk to anyone privately who is considering their first track day. Driver Education days are a very entertaining experience, as well as being good for you and your family on public roads as others have said.

Gary

SB

I highly recommend leaving PSM on all the time, even if you're driving very aggressively. It will let you rotate the car without intervening, or at least it did on 997S, and will only cut in if you're doing something seriously wrong and/or going sideways at a decent angle.....and you will still have to correct with other inputs (ie steering, pedals, etc). I doubt that even a pro race car driver can go faster with PSM off.

Now that's not a blanket recommendation for all cars. In my E46 M3, for example, turning off stability control was the first order of business at the track. In a porsche, PSM works sort of like an insurance policy and never gets in a way of your driving....drifting excluded.