stumpmj

iTrader: (1)

FYI if anyone is interested...

I just got back from the track yesterday and ran Nitto 555 R2 tires (275/40-17 all around) for the first time. I really liked them. They stuck well, gave plenty of warning before exceeding the limit, and when they did lose traction, it was very gradual without any sudden breakaway. I'm extremely pleased with the tires although thy highlighted the lack of camber and the crappy limited slip. Huge wheelspin in third gear corners (inside wheel only) and the inside 2-3 inches of the tires has yet to tough the pavement.

I wasn't as happy with the brake pads. I ran Pagid Orange pads with my Stoptech's and they were only OK. They lacked the feeldback that I got from Carbotech XP-9's and I experienced some fade after pushing very hard for several laps straight. On the bright side, they didn't leave deposits on my rotors. I think I'll be trying Cobalt Friction pads next. Any other recommendations?

350ed

iTrader: (17)

I've run Ferodo 2500's and they seem good for my level so far. You may benefit from the 3000's. I got some good pricing from Performance Nissan.

What wheels are you running for the 275 all around?

THX723

iTrader: (3)

So what's preventing you from running Carbotech XP9s again? I'm curious because I'm considering running the XP9s w. my 13" Stoptechs and if there's anything I should know about ... please do.

ALong

iTrader: (12)

The Pagids are awesome brake pads (have used them on my racecar for sometime) so I suprised at your comments. They may not have the initial "bite" that some of the metallic pads have, but you can get your mind used to that (mechanically they are bitting just as hard as your other pads, you just dont get that feedback through the pedal).

As far as brake fade goes, what are you considering fade? Is your brake pedal getting soft? or is the pedal keeping the same feel and your braking distances are getting longer?

If it is the pedal that is getting soft, then it is a brake fluid issue (ie: you are boiling the brake fluid). I would be real suprised if you got fade from the pads themselves, their maximum operating temprature is around 1100 degrees and to get fade you would have to heat them up higher than that. Real doubtfull you can accomplish this in a street driven car.

The oranges are the same compound you see on most of the ALMS, GrandAm GT, and FIA European GT cars and they dont experience fade with the pads.

stumpmj

iTrader: (1)

350ed: I'm using 17x9 MB Motorsports Comp wheels from discount tire. They're cheap and the offset is right. I didn't experience any rubbing at all.

THX723: The problem I had with XP-9's is that they left pad deposits all over my rotors. Each track day I used them the deposits got worse even using Stoptech's recommended bedding procedure. Maybe it was something else I did that caused the problem but I didn't have any deposit issues running the Pagids. Other people have experienced the same problem running XP-9's on their Z's.

ALong: I believe the fade I experienced was pad fade. At first I know that I had fluid fade due to air in the lines but after a few bleeding sessions, the pedal seemed to stay firm and I needed to increase pedal pressure to achieve the same stopping distance. I think that the fade is less of a pad issue and more of my car crying out for some brake ducting. Then again, I might have been misinterpretting feedback from through the pedal. I'll definently be doing another track day on the orange pads (they still have lots of life left) so I'll try and pay closer attention to their performance (and the air will definently be out of the system by then).

THX723

iTrader: (3)

Blahh ... I was hoping to not hear that feedback from you. Those XP9s are incredible pads. Have you try contacting Larry at Carbotech? ... it's a good thing I decided not to order the pads earlier today.

John

iTrader: (17)

I've been using Cobalt VRs for some time now, and I love them! Great operating temperature, rotor-friendly, and long lifespan. I'm personally not a big fan of the Carbotechs, but many people swear by them. BTW, mcclaskz on here has used VRs, XP8s, and XP9s on his Stoptech application, and he much prefers the VRs. I should also mention that it comes down to personal preferences for brake feel. The VRs have a linear feel, while the XP9s are more exponential. The VR compound has won lots of races, including the Rolex 24hr race. Plus Andie @ Cobalt has top-notch customer service...

ALong

iTrader: (12)

Stumpmj,
I think your are experiencing two problems, first a general lack of cooling around the brakes (more on this later) and boiling brake fluid. The problem is not with the pads.

What brake fluid are you using?

You can fix this problem by doing several things. 1) Go to a brake fluid with a higher wet boiling point. 2) Cut off the dust shields/brake disk backing plates from behind the rotors. These just act as heat sinks (keeping the heat in the brakes) and effectively reduce the cooling area of the brake disk in half. 3) Intall brake ducts, but I dont think this is needed if you follow 1&2.

In my experiece Pagid makes the best Brake pads. Pagid is a Carbon/Ceramic pad where as most of the other brands are Carbon/Metallic. Carbon/Metallic pads have a better initial "bite" feel to them, than the Carbon/Ceramic but the problem with Carbon/Metallic is that the metal compound in the pads holds heat and consequently the pads retain heat, overheat quicker, and cause the other brake components (disk/caliper) to overheat quicker as well. Carbon/Ceramic does not retail heat like Carbon?Metallic and consequently dissapates heat at a higher rate. Check out Pagidusa.com, they have some really interesting technical information on this..

Other drawbacks to Carbon/Metallic pads are shorter rotor life (they tend to heavily groove the rotors and wear them at a higher rate), and the Carbon Metal dust the pads put off. The dust comes off the pads heated at some super high temprature and the metal dust immediately clings to everything (Paint/Wheels/Suspension etc) and imbeds itself in the surface, then as soon as you get moisture on that surface the dust immediately starts to RUST. I have learned the hard way, ruined the finish on a set of $3500 race wheels and took a day at a detail shop to fix the paint on my racecar.....

stumpmj

iTrader: (1)

Along: I'm running Motul 600 fluid and the dust shields are long gone. I'm definently leaning towards brake ducts for the front at least. I'm also thinking of trying to install thermocouples in the backing plates of the brake pads to see how hot they're actually getting. I just need to borrow some stuff from work before my next event and figure out how to run the wires. I figure I'll zip tye a fluke with a peak hold on it somewhere in the car and see what the temp actually reaches on the track.

I'm actually wondering if I'm having problems with the rear brakes. I may just buy an infrared pyrometer and check rotor temps after a few hot laps. Oh well its only money.

Does anyone have any experience using Paid Black pads? Or a Carbon-Ceramic with a really high coefficient of friction?

THX723

iTrader: (3)

Give the Colbalt VRs a shot. The specs are very comparable to the Carbotech XP9s ... if not slightly higher.

I think I will be skipping the XP9s, sighting your 'smearing' issue.

Blue Liquid

I can vouch for the Cobalt Spec VR, I've used them at Pocono, Lime Rock, and Summit Point, and they've performed flawlessly. Also, do the Nitto's come in a 245/45-17? And where did you buy them from?

stumpmj

iTrader: (1)

The smallest 555R2 available is the 275/40-17. Everything else is even wider 18" sizes. I bought them from the Discount Tire for $160 ea plus $10 extra to have them heat cycled. I was browsing thorugh prices at http://www.aimtire.com/ and they seem to have great prices on RA-1's in all sizes (I don't know if they ship). Depending on how long the Nitto's last (the front outsides are disappearing rapidly due to the total lack of camber) I may try my luck with Toyos next.


Back to the topic: can someone recommend a better method to bleed brakes than the old two man pump the brakes-crack the bleeder-close the bleeder method? I want to make sure all the air is out to make sure I'm not boiling the fluid.

ALong

iTrader: (12)

Stumpmj,
Get rid of the Motul and go to the Castrol SRF, has a higher boiling point.

If you want to get brake temps, purchase some temprature strips and you can stick them right on the caliper, backing plate of the pad and on the disk hub. You can get these at any raceparts supplier. Cheaper and easier than hooking up a sensor.

daveh

iTrader: (9)

I've been using the porterfield R4 pads for years with great results. I have put 2 track days on them with my new stoptech kit as well. They're rotor friendly and I've never heard of anyone overheating them. They create a lot of brake dust but it is not corrosive (washes right off without rusting). I've also used PF-97's. They're bite characteristics are similar to the R4 if not better, and they last longer. But... they are very corrosive like someone mentioned above about metallic compounds and the hot dust will stain your wheels and paint. They emit a great spark show if you drive them at night.
Another method of bleeding brakes is using speedbleeders. Some people have found these to leak, but I just wrapped them in teflon tape before installing them and have never had any issues.