btw, bigger isn't always better. PAG spent a lot of money researching and figuring out biasing for the brakes. i have a friend who runs brembo 8 piston on his GT3, the absolute worst thing i have used. sure, it brakes well. but it's like an on/off switch. i touch the pedal with my pinky and i get catapaulted toward the windshield at TH T1. i was harness in with 6 point belts, else i would be out the windshield. i take my progressing breaking on my c2 or gt3 over the giant brembo LeMans anyday.

 

Mooty,

Interesting. Thanks for the feedback. In fact, I did not bed the pads in according to Pagid's procedure....but...it is my understanding that the bedding procedure is to insure an even brake pad material distribution into the rotors. BTW....I did not replace my rotors (which Pagid says is OK). Anyways, instead of bedding them in according to their procedure, I usually take it very easy on them for 200 miles and I don't leave the pads on the rotor after a hot stop during this time to insure an even distribution of pad material. The other reason I do this is that I don't really have a good place to do the bedding procedure near my house. Can anyone tell me if I'm way off here?

As far as Buttonwillow, I've run it probably 15 times and have never had a problem with Pagid Blues in my C2. The problems started when my lap times got below 2:21. When I was slower, I never had a problem. I'm sure my Turbo is much faster on the straights than my C2. My C2 was about 600 pounds lighter than my Turbo though.

When I brake now, they are noisy and juddering like there is uneven distribution or glazing. I'm hoping the pads will wear this off the rotors.

Here's some info that I lifted from the Stoptech website on bed-in procedure:

"What is brake pad “bed-in� anyway?

Simply stated, bed-in is the process of depositing an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. That’s it. End of discussion. Ok, not really, but although bed-in is quite basic in definition, achieving this condition in practice can be quite a challenge, and the ramifications of improper or incomplete bed-in can be quite a-a-n-n-o-o-y-y-i-i-n-n-g-g.

Abrasive friction and adherent friction

There are two basic types of brake pad friction mechanisms: abrasive friction and adherent friction. In general, all pads display a bit of each, with abrasive mechanisms dominating the lower temperature ranges while adherent mechanisms come more into play as pad temperature increases. Both mechanisms allow for friction or the conversion of Kinetic energy to Thermal energy, which is the function of a brake system, by the breaking of molecular bonds in vastly different ways.

The abrasive mechanism generates friction or energy conversion by the mechanical rubbing of the brake pad material directly on the rotor disc. In a crystalline sense, the weaker of the bonds in the two different materials is broken. This obviously results in mechanical wear of both the pad and the rotor. Consequently, both pads and rotors are replaced when they are physically worn to their limit and are too thin to endure further service.

The adherent mechanism is altogether different. In an adherent system, a thin layer of brake pad material actually transfers and sticks (adheres) on to the rotor face. The layer of pad material, once evenly established on the rotor, is what actually rubs on the brake pad. The bonds that are broken, for the conversion of Kinetic to Thermal energy, are formed instantaneously before being broken again. It is this brake pad-on-transferred brake pad material interaction on a molecular level that yields the conversion process.

With the adherent mechanism there is much reduced rotor wear as compared to abrasive mechanism, but it’s not a free lunch – pads now become the primary wear element in the braking system. And even though rotors are not mechanically worn down with adherent systems, they still will need to be replaced on a regular basis due to cracking reaching a point of failure if they are exposed to intense, repetitive thermal cycling. This is why race teams throw out rotors that are actually as thick or thicker than when they were brand new. It’s due to the an adherent brake pad transfer layer!

The all-important transfer layer

As stated above, the objective of the bed-in process is to deposit an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. Note the emphasis on the word even, as uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

Let’s say that again, just so there is no misunderstanding. Uneven pad deposits on the rotor face are the number one, and almost exclusive cause of brake judder or vibration.

It only takes a small amount of thickness variation, or TV, in the transfer layer (we're only talking a few ten thousandths of an inch here) to initiate brake vibration. While the impact of an uneven transfer layer is almost imperceptible at first, as the pad starts riding the high and low spots, more and more TV will be naturally generated until the vibration is much more evident. With prolonged exposure, the high spots can become hot spots and can actually change the metallurgy of the rotor in those areas, creating “hard� spots in the rotor face that are virtually impossible to remove.

Bedding fundamentals

In general, bed-in consists of heating a brake system to its adherent temperature to allow the formation of a transfer layer. The brake system is then allowed to cool without coming to rest, resulting in an even transfer layer deposition around the rotor circumference. This procedure is typically repeated two or three times in order to ensure that the entire rotor face is evenly covered with brake pad material. Sounds easy, right? Well, it can be if you have the proper information.

Because the adherent temperature range for brake pads varies widely (typically 100°F-600°F for street pads and 600°F-1400°F for race pads), each bed-in needs to be application-specific. One could try to generate a one-size-fits-all procedure, but too little heat during bed-in keeps the material from transferring to the rotor face while overheating the system can generate uneven pad deposits due to the material breaking down and splotching (that’s a technical term) on to the rotor face.

In summary, the key to a successful bed-in is to bring the pads up to their adherent operating temperature in a controlled manner and keep them there long enough to start the pad material transfer process. Different brake system designs, pad types, and driving conditions require different procedures to successfully accomplish the bed-in. The recommended procedures below should provide you with the information you need to select the bed-in procedure appropriate for your application."

 

Ditto most everything mooty said........from here it sounds like you are investing in brake cooling when you don't need it......Sounds far more likely you had 'pad fade'........ and/or poorly beded pads.

Pagid has specific bed-in proceedure.........don't do it and you pay.
Just my opin.

 

If improper bed-in was all it was, then the fix is easy. Just bed-in properly next time.

I wonder if my pads are toast now. They are grinding and juddery and there is unven texture and color to the rotors.

 

Here's the response I got from Charlie who I believe is the Pagid rep....he's been very helpful:

"Hi Jake,

Sorry to say, but the miles on the street didn’t really help. The pads were really bedded at the track & probably not done ideally.

Not enough bite was probably fade due to over heating. By over heating the pads & never letting them cool down slowly isn’t the best for the pads or the discs. When the pad is overheated, brake pad material starts transferring to the disc & usually results in a pedal that vibrates or shudders. The white discoloration is normal (you are burning the paint).

So, you need to rebed the pads correctly (at the track) & hopefully the friction material on the disc will go away.

It is possible that you are exceeding the operating temperature of the Sport Pad & will continue to have pad transfer. Remember, the Sport Pad is for high performance street driving & mild driver education or time trialing not all out racing.

Yes, you may need to switch to the RS4-4 compound. Let’s get the pad issue solved & not mess with the discs......

Good luck,

Charlie"

 

I’m not an expert here, but we track a stock 2002 Turbo at ButtonWillow regularly and run all the sessions with two drivers. No cool down between sessions. We have never had any problems with brake fade. Could this be something else maybe?

 

Thanks for writing. Well...I think the quote says it is something else....my improper bed-in procedure.

I previously ran stock pads and totally cooked them at Button. So either, the stock pads were not bedded properly, I'm braking incorrectly, or I'm going pretty fast and braking hard.

I've had instructors in my car and I've never gotten any comments about braking incorrectly though.

 

I have been reading this thread going on it's interesting really. I think that different drivers have differing approaches to speed and will use various components of the car unique to thier own style. So, some will be harder on the brakes than others. Some will prefer more or less understeer/oversteer in a setup. So I would first of all caution there is no "one size fits all" answer to be had for brakes.

In my humble experience bedding them in correctly is very important. Second is a really good pressure bleed before every event. And from there on it all depends upon how you drive and how hard you use them. I did put the SS lines on my car and I believe the pedal is firmer because of this. I also have the GT3 front air deflectors. I also went to the Blue fluid. But that's the end of my brake mods, and to this point I'm pretty satisfied. I might someday upgrade to the aluminum hat rotors just because the idea of the lower unsprung weight appeals to me.

As a last note, I've also found that at the track is important to work the brakes up to temperature more slowly than to barge out of the pits at full press and really nail them in the first turn.

Just my 2 cents........

 

Jake,
You found your own solution. We (StopTech) never recommend the Sport Blues for track work. In fact, we ALWAYS recommend having a dedicated set of street pads, and a dedicated set of track pads. The Pagid Orange (RS 4-4) and Black (RS-14) pads are great choices for the track. I believe you were simply operating your pads above their max temp. range.

Each pad is designed to work under a certain set of parameters. Here are the basic elements that you should consider when choosing a pad:

1. COLD STOPPING PERFORMANCE. How well does the pad grip on the first stop when the system is at ambient temperature?
2. HOT STOPPING PERFORMANCE. How does the pad react at higher temperatures, such as on a road course? Rotor and pad temperatures typically exceed 1000 F on road course
3. PAD LIFE. How long will the pads last in a given driving environment?
4. ROTOR LIFE. How aggressive is the pad on the rotor, and will it groove the surface?
5. NOISE. Does the pad squeal? High performance pads will always have some noise.
6. DUST. How much dust does the pad generate, and how easy is it to clean?
7. COST. Is the pad affordable compared to how it performs?

There will always be tradeoffs with each of these items! There is no magic pad compound that can perform well in all of these categories. A pad that has a very high max temperature is designed for the track. It will make noise, make dust, eat your rotors when driven cold, not have much bite at all when cold, and generally make daily driving unpleasant. On the other end of the spectrum is the OEM pad. They are designed to be quiet, bite when cold, and have a long service life. All pads fall somewhere in the middle of the two extremes.
The Pagid Sport Blue is a pad that tries to bridge the gap between the street and track (sort of like a Hawk HP+). It works well for autoX or canyon driving, but if you thrash it on the track you will exceed its limits. The Orange is about as close to a dual-use track/street pad as you can find. You can get away with it on the street, but it will make some noise, it will be harder on your rotors, and it will not bite cold quite like a straight street pad will. It has a pretty nice temp. range, and can be used hard on the track. The RS-14 compound is pure race. It wails like a banshee cold, if there is no pad transfer layer.

As for an upgrade path, we typically recommend a stepwise approach to fulfill your individual needs. First, get some good fluid. We like Motul RBF600 in terms of bang for the buck. Next, get some good race pads for the track (either of the Pagid pads discussed, or something like a PFC 01 or PFC97). Keep your street pads for the street. Try this setup. If you are still exceeding the heat capacity of the system, you have some options. 1. Get some ducting as others have mentioned. Ducting will put more air into the rotor and help keep temps down.
If you are still fading the system, you need even more heat capacity. The next step would be a full big brake upgrade. Rotor mass and vane design is where you'll gain the most heat capacity. Our BBK for the 996 turbo steps up to a 355mmx32mm front rotor. The additional mass will store more heat...think of your rotors like big heat sinks. Also, a rotor with good internal vane design will pump more air through the rotor and help with cooling. My guess is at this point, you wouldn't need anything else. There are more options, but you'd really have to be wailing on the car to exceed the heat capacity of a system such as this.

As for Buttonwillow, it is not that easy on brakes IMO, once you get moving quickly! It is much harder on brakes than Big Willow, Streets, or Cal Speedway.

Some other helpful notes regarding rotor management...
A lot of our customers use their car as a dual street/track car. This poses the issue of swapping back and forth constantly from street to race friction. Here's what I do when I go to the track in my 350Z.
1. 2 days or so before the event, I swap in my race pads. Since I have a layer of street pad laid down on the rotors for daily driving, the goal is to get that layer off before I arrive at the track. Daily driving on race pads cold will quickly scrape off any pad material on the rotors. When you first put the race pads in, they won't make as much noise, because they will be in contact with the layer of pad on the rotors. As that layer scrapes off, they will start squealing more and more. If you visually inspect the rotors after you've done this, they should look silver and clean in the swept area (normally, they should have a greyish/blueish tint in the swept area...that's the pad material on the rotor that you've laid down). You just have to be careful when doing this though, to leave a little extra stopping distance since the pads won't bite much when cold.
2. When I get to the track, I do a bed in either on the track or on nearby roads if safe. Out in the desert at Willow Springs or Buttonwillow, there are some nice straight roads with good visibiilty. I do a bed in cycle on the race pads to get a transfer layer laid down on the rotor (follow procedure on our website). I don't recommend exceeding the speed limit, etc. (covering my azz here ) The other option is to do the bed-in during your first session on the track. Let the brakes cool after, and DO NOT COME TO A REST WITH YOUR FOOT ON THE BRAKE PEDAL EVER WHEN THE BRAKES ARE HOT!!!
3. Run your full track day...enjoy the thrill of putting your shoulder belts to the test under heavy braking.
4. After you've packed up all of your gear, etc., drive home on the race pads. You may or may not need to leave them in for another day to scrape off all of the race pad material that you had laid down at the track. They will start squealing again...visually inspect. The idea is to clean the rotors of all pad material.
5. Put your street pads back in.
6. Do a full bed-in cycle on the street pads again to lay down a transfer layer.

I've been following this procedure for 8 or 9 track weekends on my current set of rotors. I have yet to have any vibrations, etc. You just have to be aware of transfer layers and how to manage them. Some pads have funky interactions when you try to stack them on top of eachother.

I hope this helps. Please check here for the answers to all of your brake questions:

http://www.stoptech.com/technical/

http://www.stoptech.com/faq/

 

I may sound like a suck up after the fact, but...

I am an engineer, highly technical, competent, but not great driver (yet), and I am running stoptech brakes...


Happily.

Tim

 

JRitt@StopTech and everyone else....thanks so much for the great technical advice. Its awesome sharing the little technical details like this with others who care. Its these small details that can make a day at the track more fun versus a horrible experience.

I'm going to get a set of Pagid Orange (RS 4-4) pads for the track and start swapping them out according to JRitt@StopTech's advice.

 

Garey also makes a great point. Not everyone brakes the same way.
Jeff great advice, thanx.