SB

If you track your 991S, please post your track experience with OEM brake pads, and more specifically whether they can stand up to aggressive track driving. Personally, I have a very hard time believing that they can, but I really want to So all you late brakers (naturally), speak up please!

Ideally, please list your setup (tires, brake fluid, etc), driving style/aggressiveness on the scale of 10, track experience level, durability of brake pads (or expectations thereof based on wear), brake feel, any fade/sponginess by the end of the session, etc.

MayorAdamWest

I think you might want to read through: https://rennlist.com/forums/991/7399...the-991-a.html

The short answer is, it depends on your experience level, how you drive, and where you're driving. I was at the track last weekend on a totally stock setup (except for Motul) and everything was great. No brake fade. But, I think that other thread is what you're looking for, with really great answers from a lot of people. I actually wish it were a sticky.

SB

Thanks for the feedback. I know about that thread and it has a lot of good info, but it's a hodge podge. I want to stay on topic of stock pads, and it would just get buried in that thread.
After all, it would be very cool if stock pads could put up with track abuse. Although I absolutely loved my Pagid RS19s, at low speeds they squeal like a bus most of the time.

hlee1169

Please see my thread. I think they are pretty good for beginners in the first DE season. You probably need more aggressive pads after you are really getting hard on your brakes.

simsgw

Wow. Talk about a perennial question. This one fuels more hangar debates than anything but tire pressures. You'll notice in that other thread that two very experienced drivers plumped down on opposite sides of the question.

I don't 'campaign' a car because I'm no longer interested in collecting trophies. I can say that I change other things to let my car deal with my driving style that inherits from racing experience, But I don't change the OEM pads. For others, it is one of the first changes. Some even change their pads at the track so they have OEM type pads for daily driving and Pagids or equal for track days.

Basically, only four factors occur to me in making this decision:

1. Ability to generate the friction levels required at maximum torque;
2. Linearity of that response with respect to brake pedal pressure;
3. Abrasion on the disk for a given duty cycle;
4. Consistency across the temperature range from road driving to maximum effort braking several times per lap.

Clearly, the OEM pads satisfy the first three for enthusiast driving on public roads or track work. The debates start about number three in serious track work and number four at all.

Granted, I've never treated this as more than a hobby question that was delaying my getting on track (). If I gave it professional attention I might think of something else to consider and I'm open to suggestions. But for now, I'd say that our opinions among serious track drivers diverge on those two points. My own approach is to increase the airflow to the brakes to hold down the operating temperature in sustained maximum effort. Having done that, I've found no problem with stock pads meeting all those criteria, including wear of themselves or the disk.

Obviously, track work creates wear faster than public road driving. Pads and disks are consumables like oil and gas, just with longer duration between replacement. But with that said, my results have still been in the nominal range for brake wear on sports cars. I'd say twenty to thirty thousand miles for a set of pads and at least fifty thousand for disks. If I were doing a dozen events a season, let alone twenty or thirty that some manage, then I'd expect to change the pads within ten thousand miles and the disks within twenty. Adjust that for your own driving style because I've had sixty years experience getting performance out of components with the least extraneous wear effects. I usually get ninety thousand out of a clutch. If I were racing again, it has to be said that pads and disks become a regular replacement item between events. I never asked my mechanic how often, but every hundred laps wouldn't surprise me. Racing is different than track days. It just is.

Except for the concern about response to high temp operation, I've never been sure what the opposite viewpoint finds as motive to use non-OEM pads. I don't disagree with their motives, I just literally don't know what they are. I suppose that aside from answering the question about what I do personally, I have tuned out and I'm thinking about my line through turn nine when this question is being discussed. I am with child to hear those reasons and may well change my own approach.

Your specifics:

• Michelin Pilot Super Sports with my 997 and with my 991 once I wear out these original Pirellis, which look fine at 6,000 miles;
• Motul 660 in SS-braided lines with my 997. The same with my 991 if I decide to drive that aggressively after conquering a current health problem, if I do conquer that health problem ;
• My driving style is mild and conservative, although my advanced students have been known to complain of shakes afterward. One describes it as not braking until you see God, but your own religious experience may vary. I prefer to think of it as analytical;
• Brake feel remains easily modulated, as is essential to effective trail braking;
• Durability: see discussion.
• No fade tolerated. Indicates need for more cooling. But when driving in race mode with a completely stock set-up the brakes "go away" after three to five laps. First time I did that in the 997, I had to drive it like an old sports car with drum brakes for the rest of the day. Students found it entertaining (with forewarning) because the style is completely different from modern lines.

I suppose that comment about driving style needs elaboration. All drivers interested in setting good times learn to brake late. They also learn to blend braking with cornering smoothly so the car's balance is not upset and the tire's potential performance is utilized to the greatest extent. That means not braking until the point where waiting longer would cause a loss of control, and "trail braking" for the transition.

Racing drivers at mid-pack and forward have learned to do more. I decline to teach driving on-line, let alone racing, but in technical language without discussing specific techniques, we learn to delay more of the energy dissipation into the trail braking phase. That means we start braking later than even a person who thinks they "late brake". If we did not, the car would be sl*wed [hate that word], more than necessary. Aside from balance braking, used to help a car handle transitions, and the mild slowing required for certain ingenious corner designs, we use staged braking that reaches the maximum the tires can support at every occasion. Every occasion. That's what I mean by 'analytical' though it startles the driver new to the visual effect.

It also must be said that I do not drive this way with a novice student in my car, and I discourage instructors from taking their novice students along at all in their own session. You cannot drive as slo*wly and smoothly as you should in a session intended for instructors and competition practice, so instructors agreeing to a "ride along" request go out in the advanced novice session.

Being in the car when we drive aggressively impedes learning technique for several reasons, so I really am "mild and conservative" with a novice in my car. I'm sure the other instructors in our company will agree with that policy.

Gary

chuckbdc

Amen.

John's 991

I have used stock pads regularly on the track and while the car stops well, they do fade with repeated heavy braking. Better brake fluid helps a lot; I am currently using Castrol. It is easy to adjust braking points and entry speeds to avoid brake fade which does not materially impact the fun or learning experience, as long as you are not going for lap times.

The pads needed changing the first time at 2,800 miles and will need to be changed again around 4,500 I think (currently at 3,600 miles), which equates to 4-5 track days per set. I will probably try the Pagid pads next time around, as well as installing stainless steel brake lines, neither of which were available when I changed the pads and fluid the first time.

The good news is that it is really easy to change the pads with only a few tools. I will probably put something up on the 991 DYI next time I change them.

shizzle

Your pad wear rate sounds exactly the same as mine. 4-5 days and that's about it. I find that after a 25 minute session the brakes will fade slightly, but they rebound pretty quickly. I've been using stock fluid (changed it twice), but this year, I'll be using Castrol SRF from the get go. Hopefully Pagid will release some RS/19/29 pads for the 991 soon!

ny991

Swizzle, thanks. I have my first track days coming in May and have been concerned about the brakes. I will try totally stock for these two days and adjust my plan after that.

SB

Pagid USA says rs29 will be avail in march

SB

Pagid rs29 is endurance pad designed to last at least 24h on a race car. Most top teams are using pagids for endurance races. While these probably won't last as long on a heavier street car, but figure at least 15h of track should be no problem.