i've never ran my car at a real track/auto x event... what are the different types of brake problems can you run into?

sometimes when pushing my car hard in the street, i feel like the brakes "skip" (best way i can describe it).. is this brake fade? i have hawk hps in the front, other then that my brakes are completely stock

 

When you have brake fade, the pedal will get mushy. This is a result of exceeding the thermal range of the pad and/or boiling the fluid.

I'm having trouble envisioning what you mean by "skip".

 

it's like a pulsating feeling, sometimes when i brake real hard i can even hear a knocking noise... could it be abs?

 

That's the ABS.

 

It could be the abs but I have only had it come on at the track never on the street. The pulsating feeling could also be brake material on your rotors depending on how you bedded them in after install.

Depending on how different you tire diameters are from stockk they might be screwing up the ABS also.

 

If it's not the ABS, it could just be that your rotors are warped; go to a brake shop and have them checked out. The rotors may need to be "turned." You might as well put some good brake fluid in at the same time.

 

so question.... if I put in DOT4 and hawks brake pads all around, how many sessions am I going to last? or lets say, how many days of track will my pads survive..?

 

It depends on a lot of things.. what track, the ambient conditions, driver, session length etc. My stock brakes (enthus. model) started to fade in my first session the first time out, but never really dropped off after that, and I ran 6, 20 minute sessions during the day.

 

I had stainless lines, Porterfield R4 pads (full race compound), and ATE Superblue fluid (dot 4), and the following happened at buttonwillow.

My brakes went out while going 110+ mph on a straight. I tried to heel and toe to slow down, brakes didn't work. I hit the brake pedal only, went straight to the floor. Tried to brake again, nothing. I ended up going straight into the dirt and was slowed down by the mud.

Failure: The backing of the pad was melted to the caliper piston. The caliper piston seal was torn on the passenger side, resulting in fluid not being able to be held by that brake. The pads were MELTED-- they were literally worthless, and I had to be towed home 150 miles (thank god for triple A and 200 free miles of towage). For your first time, fluid, lines, and pads will be plenty for you. Prolly for the second track day too. If you start getting serious about it though, don't waste your time nad risk your safety (like I did)... just do it right and get some Stoptechs or some big brake kit.

I know this is an extreme case, and I'm pretty quick around the track, and i'm not trying to scare anybody-- just letting you guys know what *can* happen on stock brakes.

 

I backed off before this happened to me but I could smell the brakes even on the track at the hard breaking slow turns. Check out my sig. I went to 350zbrakes.com and now see 6 track days per set and no fade. A big brake kit all the way around is a must if you plan to do more than a couple of track days per year.

I love my track setup now with the combination of suspension by 350EVO and 350zbrakes.

 

I did the same thing. I caught it before the seal came out of the caliper though so no off roading. I think if you run a low friction compound in the back (I've been using Hawk HPS since my incident) you won't have any rear brake issues. You definently will want the front brakes upgraded though. Also, remove the dust shields from behind the rotors. That seemed to make a big difference for me.

 

I have done several track days with a myriad of brake pad compounds. I think the porterfield R4 are junk for the stock brakes. Their service was very bad as well. The pads were originally shipped with the wrong size backing plate on them. The fronts were fine but the rears were off by 3/8". They told me to just cut and file the edges until they fit. I prefer pads that are made properly, especially for the premium they wanted for them. The compound held up pretty well, but are torture on the rotors. EBC Redstuff Ceramic is a good compound to buy, they are relatively cheap, lasted three sessions, and had really good feel when heated up. They are also a lot easier on the rotors. Hawk HPS are in the same league as Axxiss Ultimates, they are great for the street, but fade too quickly at the track, they also print on the box not intended for race use. The plus is you don't need to change pads for the event and are very easy/ low dust for rotors. I recommend the EBC for a good compromise, heavier duty for the track but still useable on the street. Of course, changing pads before an event really isn't that hard and allows you to bleed the fluid out of the calipers each time as well, just an extra margin of safety worth the time I think. The fluid should be completely bled out and replaced with a good synthetic DOT 4 compound. A lot of people, myself included, go to the track with Motul RBF. It is really great, but a bit pricey for some at 14.00 a bottle. Some guys who autocross and do time trials aound here have used off the shelf Valvoline Synthetic from Pep Boys and really like it, but are dilligent in bleeding calipers before every event and the system once a year. I hope this helps you out, the stock brakes can take quite a beating with good fluid and brake pads. I have pulled in from laps with mine smoking and near glowing, but have had no problems yet. For really consistant and hard on track days and for extended lapping though, I think a BBK should be in your future. have fun.
Will

 

I have this brake problem on the track where I continuously push my braking zone farther and farther because my Stoptechs inspire such confidence, until I'm forced to take a really bad line cause I went in to the turn too fast. This happen to anybody else here? For track days I run Cobalt Spec VR pads (full race pad), Motul fluid and R compound tires.

 

Absolutely. I've shot off the track a few times testing various turn in points and practicing my trail braking. It's scary at first but once you become really familiar with the local tracks and what can bite you, your confidence comes back.
I'm running stock Brembo calipers with brake pro's slotted rotors, Carbotech XP8 mild track pad, Motul RBF600 fluids and R compound rubber. Very rotor friendly with little to no fade (although pedal feel has decreased compared to stock).

 

Basically, you can:

a) run out of pad material. This might happen if you run stock pads. But it mostly happens because most people don't know how to brake on the track! You need to get on the brakes quickly and very hard, then let up quickly. You want maximum braking for the shortest possible time. If you "drag" the brakes like most of us do on the street, you will overheat your brakes badly, transfer LOTS of pad material onto your rotors, and run out of pad material very quickly.

b) boil your fluid. Old fluid pulls water into it, which boils off under hard braking. The air bubbles make the brake pedal feel soft and your brake torque drops dramatically. The solution is to use a good, high-temp fluid like RBF600 and bleed the system constantly.

c) Overheat your brakes. Even if your car has huge Brembos or Stoptechs, brake cooling sucks on most street cars. You need air directed into the center of the rotor so it can blow out through the vanes and cool it internally. Also, some air to the calipers can keep fluid temps down. If you can't get good ducting into your brakes, then at least remove the stock backing plates and consider using high-temp pads and fluid.

There are other problems that can arise, such as cracking a rotor or "warping" it (usually a pad transfer issue and not real warpage). But the three I listed are pretty common when you run a street car on the track.

That sounds like the ABS kicking in. It's totally normal.

Emre