Chris White

I have found a new way to judge my braking points when I give newbies a ride on the track. Its usually after the screaming stops and just before the peeing begins.

Something to watch out for – as you get to drive faster and get the brakes sorted out the universal response is to brake too much. All most all intermediate to advance drivers with powerful cars over brake into corners (a lot of instructors too!) If you are braking from 150 to 75 in a short distance it is quite hard to the timing right to have the right initial braking point to allow for full use of the brakes up to turn in and still have some speed to drop off during the trail braking. This is where having a completely dependable barking system is really important!

Chipster

There was a lot of triming of involved to get the duct to fit nicely beside the oil cooler, but, as Jerome mentioned, it was an almost straight shot back to the spindle mount.

Be careful using pool hosing - or something similiar. The temps get very high - especially around the brakes. The orange tubing is specifically designed for brake applications. It's more expensive - but it won't melt.

67King

The usual complaint I read here about the pads is that they are so aggressive that they go through rotors too quickly. They are the best selling pads for SCCA racing, and they are the pads that all of the club racers I know use. If you look at their lineup, they only sell one pad that is more aggressive that is not intended for open wheel cars/cars with lots of downforce.

I think Chris nailed it. I've got no cooling, whatsoever. Not even the factory deflectors.

67King

I kid with my father-in-law about this. I did not get very far for my first event (so technically, I've had five, but I don't really count the first one). His car had mechanical issues, and I never got a full session in. I kid that he tried to kill me three times that weekend. The first was when I went out there, and the throttle stuck open (as a result of the intercooler hose clamp being clocked wrong and catching the throttle spring). Luckily, it wasn't stuck wide open, only partially, and I got it into the pits with no issues. The second was when the rears locked up on me. He had always had a problem with sticky rears, even when it was a street car, but he had dismissed it as a quirk of hte car, and learned to drive through it. I ended up losing it going into 10A and kissed the wall, ending my weekend on the first day, and without a third session.

The third time he tried to kill me was when he tried to give me a heart attack when he took me out with his run group. I told him if he wanted to get rid of me, he should have done that before he gave me permission to marry his daughter!

I have absolutely experienced this. Or I should say I am experiencing this. I used to absolutely nail 10A, but as I got faster, I had to brake earlier, but then I braked too much, and couldn't trail brake into 10A, which kept me from getting the car to rotate like it had earlier. Used to be my best corner on the track, and now I can't hit it to save my life. And as 10B leads to a steep hill, losing the momentum just destroys the entrance to 12, and subsequent front straight speed.

Fortunately for me, I had noticed some fade before I lost my brakes. As a result, I was braking earlier into corners to ensure I could slow it down enough. Had I not done that, there is no question that I would have run off of the track when the pedal went to the floor.

Tay-Tay

What Chip said.


Realy a lot of great brake info, thanks all.

Taylor

MK3DUB951

definatlly learned alot about brakes (aswell as things to do and not do when i get back and start learning on the track!) cool set up though, seems like a good thing to take care of before i start!..

Oddjob

To backup a little - another general comment for anyone having brake problems: air in the system is also a possible cause of fade. Any time you have on track braking problems, especially a soft pedal dropping to the floor, I would first ensure the system is well bled. As with warping rotors, actually boiling the brake fluid is pretty uncommon with p-cars. Its not difficult to get air into the system, and any time air is introduced, it can be surprisingly difficult to get out. Almost more so with power bleeders. On 944s, its often traped in the rear lines and calipers, so the fronts still function normally. Brakes will seem ok at first, but as the system heats up on track the air in the rear lines expands making the pedal feel worse and will eventual lead to brake failure.


Hawk 9012s are not a very aggressive pad for track cars. Again, a good DE pad and they’re a popular club pad because they are less than half the price of the race compounds. There are three current Hawk pads available that have higher heat ratings and higher torque than the Blues - DTC70s, 60s, and HT10s, all for GT Road Race applications. Pagid Orange, Blacks and Grays, PFC will have at least two compounds, and other brands will also have 1-2 compounds that are more of a race pad than the 9012s.

http://www.hawkperformance.com/motor...cations/gt.php

NOTE - some of the real aggressive pads might be too much for a car running an intermediate tire like a toyo RA1 or equivalent. Too much ability to lock them up. Hoosiers and similar sticky DOT R tires can take much more advantage of the higher torque pads. Obviously, this is also much less of a concern if the car has ABS.




My observations are based on experience from tracking 944s since '92, 11 years of club racing. So I have seen and learned a few things about driving these cars hard. I have used a lot of different pad compounds and different cooling arrangements and fought with plenty of brake problems over the years.

Jeff N.

Jim - do you like the 968 pickups? I've thought about putting them on my 86 for a bit more cooling.

While we're musing on brakes, any suggestions on mitigating rotor cracking? I'm seeing a fair amount of cracking on my front rotors. Had one set crack out, carefully watching this set.

My setup - 86 turbo some slight engine mods, stock calipers and cooling setup, running PF-97's with ATE superblue. A group speeds.

67King

That is certainly a possibility. I flushed the brakes in March with a quart of Ford Super Duty fluid (very popular in some circles due to its low cost and very high dry boiling point - but it drops off drastically when wet). I then drive it about 100 miles - first time on the street with the car since I bought it in April, 2009. After I did that, I then flushed all of that out with a liter of ATE super blue, to be good and sure that I got rid of any trace of old fluid. However, I must confess that I had not seen the internal bleed screw, so it took me a while to figure out what was wrong. I still beat like mad on the calipers when I was bleeding (with a Motive), but if I had that air trapped in there for so long, again with continued beating, I could see that I might have some trapped air. I'm just surprised it did not show up earlier.

Regardless, I'll be flushing the system out again when I replace the fronts with the S brakes.

I had read the other compounds you listed to mean they were to be used primarily wtih open wheen cars and cars with a lot of downforce. I actually wanted a street/track pad, but was advised that if I was running anything faster than about 1.50 lap times, they wouldn't last the weekend. I'd been (wristwatch) timed a tad under that, so I went with the track pad.

Thanks for all of the insight!

968 GUY

Chris, I thought the fans went at all 4 corners, and affected the handling by how much they cool the brakes at each corner of the car, for example, turn off r/f fan, brake retains more heat, and either increases or decreases braking(not sure if NASCAR pads work better hotter or cooler)

Oddjob

I do like the 968 scoops. Cleaner install and cheaper than the purchased cool brake kits. I have used these scoops on several track cars and cooling has been adequate. I do have a cool brake kit that came on a car, so I have kept it. Cant say I notice more cooling than the 968 scoops, but probably does offer a little more direct air.

What rotors are you using? Solid, drilled, slotted? Porsche OE or Zimmerman?

Solid OE last the longest. But the front rotors will eventually crack through. Solid rears are often worn down past the wear limit before they crack, but drilled rears will crack before wearing down.

Once you start tracking cars, you pretty much have to get use to the idea that rotors, along with pads, are consumable items - same as tires, gas, oil and rod bearings...

Oddjob

I have used the Ford DOT 3 brake fluid for a lot of years. Used to be called Heavy Duty and came in a 1 gallon jug, then in blue metal pint cans, now its in little white plastic cans with a red label, I think called High Performance. As you said, high dry boiling point and really cheap so no concern about wasting a bunch to ensure you get a good flush.

Anytime you change any components (lines, calipers, MC, bias valves, etc) you get a lot of air in the system. Thats when I have had the most problems with bleeding. One technique is to bleed the rears with the rear of the car higher than the front. Cant say for certain it is necessary, but I have seen it done. And the problems I have had bleeding have either been with the rears or with ABS cars and the air gets caught in the ABS pump.

Its best not to screw around with a compromise pad on the track. Brakes are the most important system on the car, and the best plan is to put in a dedicated track/race pad. If you use the car on the street, either deal with the squeaking or swap street pads back in. So the hawk blues were a good choice. I just offered the option of trying a more aggressive, higher heat pad because of your fade issues.

I used a lot of hawk pads in my old 944S, because pagid did not make a pad for the single piston N/A calipers. I used some blues in my then F class (now E) 951 and then went to pagid orange, then blacks. With my G class 951 Cup (TS/M030 calipers), I ran pagid blacks, but have now tried a couple sets of DTC70s front, 60s rear. The 70s are really grabby, some might feel too much. I dont have that refined of a touch with the brakes, pretty much just stand on them, so they are fine for me.