seeking input, Pagid RS19 vs. RS29

[Randy Blaylock]

Anybody have any experience and/or objective testing data with these Pagid compounds?

[Bill Verburg]

I use the 19s, they are very good for track w/ ocasional street use.

they squeel a bit when cold and/or lightly applied

The 29 is a spomewhat higer friction version w/ limited availability

14 is probably best for track only race pad

[Randy Blaylock]

Thanks Bill,

*full disclosure* the application is non-porsche...

It's a 3385 lb. World Challenge Spec Viper w/505rwhp, on 315/335-18 R6 tires, the calipers are the real brembo racing gold anodized monoblock type, over 355 x 32 and 328 x 28 floating brembo rotors. Lots of ducting, multiple 3 inch hoses. The tracks here in the pacific northwest are varied, but generally aren't terribly hard/high frequency use on brakes. Typical max velocity is 170ish to a tick over 180 at Spokane Raceway Park.

I got the car with 30+ boxes of PFC brake pads in various compounds and have tried several. The performance of the brakes is fine. The principle issue has been rotor cracking, such that the rotor service life has been <10 hours. Given the spares package I have in inventory of extra calipers and rotors, it's not financially feasible to try a larger rotor package at this time so I'm left with trying to manage the issue with pad selection. The common opinion is that the PFC pads are the major contributing factor, and I'm going to try some Pagid pads since I have had good results in my Porsche applications.

I agree the RS14 compound would probably be best from a pure performance perspective, but my priorities are focused a little more on service life now, assuming sufficient performance.

19 and 29. The size is available, #1896/1607.

So at this point I'm mainly curious if there is a major distinction between the RS19 and RS29.

[Bill Verburg]

The 29 has a higher m and will put more heat into the rotors more quickly and will exacerbate the cracking issue. It sounds like everything that can be done to cool them has been done(except maybe blowers?)

the calipers you are using are the Brembo 07.5169 front and 07.5139 rear.

[DW SD]

which colors refer to which Pagid Pad numbers?

I just installed Pagid Oranges on Turbo calipers and rotors all around. Even after break-in, they squeel like a stuck pig, especially under light braking and very slow speeds. It drives my wife crazy.

Their dynamic friction definitely goes up as they warm up. After 5 to 6 70 to 10 mph stops, they are more confidence inspiring than cold. Of course, that is expected with track pads.

I'm sure some guys can offer much more relevant objective data.

Doug

[Randy Blaylock]

My info shows the calipers as X9 and X2 something, not that it matters that much. An easier reference would be to say that the PFC pad shape is 7770 and 7700. Bill, do you have any experience with PFC compounds, for instance can you draw a comparison between the common PFC compound numbers and Pagid's compounds? For instance, PFC 83, 93, 99, 01, 03? FWIW, one other change I was able to make that may help is to try a brembo rotor with 72 vanes. It will be very interesting to see how the Pagids behave from a performance standpoint relative to the collateral issues.

[hobieboy]

Randy,
Just found this thread to continue my response...
My buddy was using Coleman rotors on his car & the PFC will simply eat thru them in a day or 2 while his Pagid (RS19 I think) won't. He was told that the Coleman were simply too soft for the PFC and he should switch to Brembo. He did, and that fixes the cracking/eating rotor problem.

So, maybe you are in same boat?

[Randy Blaylock]

It's possible. I have used Coleman rotors in the past in other applications with reasonable success, but this car is in a different league with the weight and speed potential.

I did contact Coleman about a custom rotor that was a 380mm O.D., but still 32mm wide and the same bolt circle as my 355mm rotors, so I could use it with my current hats and brake cooling backing plates. I would have needed to space the caliper out radially, and the annulus of the rotor would have been much wider, but there is a 7772 pad shape that would fit in the caliper that would have swept much of that.

It was a possible way to increase the torque, to minimize the bias needed in theory, but they could only do 32 vanes, and the air gap was quite wide so the cheeks were thinner than the Brembos. Not to mention they wanted almost as much @ $350ish as Brembos, so there wasn't much inducement to experiment.

Not to mention the thermal issues would likely have been accentuated, so I am going to try the 72 vane Brembo rotors with slightly thicker cheeks, and one of the Pagid compounds.

[BertBeagle]

From your description, your problem might be too much cooling on the rotors. Although if you are running the car hard and are getting 10 hours life while getting familiar with the car and lots of heat cycles on the rotors – that just might be normal life.

If you feel you should be getting more life then I would use some of the temp paint on the rotors to show what the operating temperature on the track is. Using the 3 color paint kit (green, orange and red) in a racing condition you want to burn off the green and most or all of the orange while getting into the red on the edge of the rotor.

If you are not burning off the green and most of the orange your brakes are not to operating temperature. If you get them to those temperatures, using the paint as a guide, you will experience better braking and longer life. You can get there by taping off some of the duct opening or, if they are really cool, by putting a band on the id of the rotor to block the air.

When you start using racing pad compounds as many or more problems result from to little heat in the brakes as from to much. The Pagid pads will not be as hard on the rotors as the PFC but you still need to get them to operating temperature.

If, in the end, you decide you need blowers for the ducting – I have the best available today. Designed by aero dynamists Yoshi Suzuka, they are used extensively in racing on hard braking tracks.

Here is information on the blowers http://www.suzukaracing.com/

Good luck

Ashley Page

[BertBeagle]

Originally posted by Randy Blaylock
I am going to try the 72 vane Brembo rotors with slightly thicker cheeks, and one of the Pagid compounds.

The 72 vane will run cooler but it would be worth knowing what temp you are at with your current set up.

Running a rotor too hot will not crack it - it will show radial grooving with most racing pads. Thermal cycling is what cracks them. The 72 vane Brembo rotor, while an excellent rotor for the right application, might also give you higher thermal cycling. From your description of the tracks you run that is not the rotor you need. The 48 vane Brembo you have should be more than adequate – both front and rear. The current Brembo racing rotors are the best money can buy. BTW is this a competition coupe?

[Randy Blaylock]

Thank you Ashley,

It's a GTS street chassis that was built from a bare frame by a team back east for the then Speedvision World Challenge. The layout is virtually identical, and the other pertinent specs are quite similar as well, so any experience with CCs may be helpful.

Great advice on the data collection re the temp paint. I hadn't had the opportunity to conduct that last year as there were simply too many other issues to deal with in the few events I was able to do. I do have some tempilaq paints to use once I get up and running again this year to check on those very issues. FWIW, there was some leftover paint on the rotors, and I didn't pay too close attention to what the original color was, or even if there was any unmelted color left, but there's not much left (melted) of whatever was painted on to begin with, which suggests to me the peak temps are pretty smokin.

The car did originally have a water spray system with two small fuel cell containers as reservoirs, electric pumps, and some sort of microswitching, all feeding a nozzle in each cooling backing plate, that had been used in the past but was not in place when I took possession that all came along in the package of spares. Jeez, I wonder if they had thermal issues :-)? The openings in the fascia were quite small, something on the order of 6 square inches or less with a fabricated scoop feeding a single 3 inch hose.

The first event I did using this arrangement used 70% of a set of new bedded front PFC 93 pads, and cracked the formerly bedded only rotors radially through both the inner and outer edges. I did run the bias a little heavy to the front, more than I typically like simply because it was my first race in the car, and I wanted to reduce the likelihood of any trail braking spins.

I then probably tripled the fascia opening and added a ram air type twin duct with complementary hoses, and the pad life was doubled at least, and the second set of front rotors lasted at least 8 hours before similar cracking. Meantime, the rear rotors had now shown similar cracking after dialing the bias more to the rear. I typically like to run a differential around 80 psi F/R.

I'm hoping that the 72 vane rotor will have a tendency to be slower to cycle due to it's increased mass, but I can't say for sure given that I don't know what efficiency increase the greater number of vanes will have on pumping air. Once again, it's down to the paint and testing.

One common sentiment I did get from the consultations I have gotten so far, is that the PFC metallic compounds tend to be excessively hard on discs, and that a ceramic type pad will be an easy thing to change and try at least for what that's worth.

Anyway, thanks for your input, I appreciate whatever you have to add.

[Craig 930 RS]

(Also posted on the 930 forum)
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Since I sell both...

Actual-use reports back to me are the RS19 and RS29 are fairly similar, with the RS29 having more initial bite - ie it has been reported back that they are 'grabby' and not in favor vs. the RS19. They are the same price.

I probably sell the RS19 in a ratio of about 30:1 over the RS29 -- and the guys who have bought the RS29 usually don't re-purchase the 29s, instead choosing the RS19s. YMMV.

PFC pads are generally thought to be excellent pads, with Pagids frankly residing on the top of the heap. For pure track use, the yellows last a long time and take a real beating - AND tend to be quite kind to rotors. And usually howl like a banshee on the street. The (RS14) blacks are great track pads, but tend to munch on rotors at a higher rate than one may like...

Cooling is of primo importance with any high friction pad, the yellows really require superior cooling. I'd highly recommend a fan setup.

Something to consider is the possibility that the thermal capacity of the discs may have been exceeded -

[Randy Blaylock]

It's looking like I'll probably try the RS19 first.

On a side note, I had a conversation with Stoptech, and they're developing a ceramic rotor with continuous fiber throughout, that's said to be superior to PCCB. The first deliveries aren't slated to come to market for some time, and the first products will likely be in kit form packaged with their calipers. They do have direct replacement rotors as an objective though.