Hi everyone,
I know it's not a Subaru, but thought I'd share this with you all, hoping current StopTech owners and prospective buyers will be particularly interested in this one...Here is a copy of a press release from our website, and some pics. In short, our rotors went the full 25 hour race distance at Thunderhill (560 laps for this car), plus an extra 100 laps of practice and qualifying. The brake system on the Bullet prepared BMW is made from the same components that are on our street kits for the WRX (actually a 328 x 28mm rotor turned down to 322mm for World Challenge rules). I thought some of you might enjoy seeing what your kits are capable of on the track...besides in the capable hands of Gary Sheehan.

StopTech Rotors Enable a Class Win and Go the Full 25 Hours of Thunderhill

Torrance, CA… It took five drivers and only one set of StopTech AeroRotors® for Bullet Performance of Costa Mesa to win their class and place 8th overall in the ultimate endurance race - the 25-Hours of Thunderhill. Seventy-five race cars, including top teams from around the country, took on the challenge of the race dubbed the “new king of enduros.”

Bullet Performance ran StopTech’s World Challenge 322x28mm brake upgrade on their #56 1996 BMW 328is. At the 12-hour mark, the team was leading their class and 7th overall. “The StopTech brake system performed great the entire race with negligible brake fade. We were able to continuously brake deep into turns,” said Chris Welch, one of the five drivers of the Bullet team and co-owner of Bullet Performance. “It was unbelievable that not once did we have to change our rotors or pads during the 25 hours of non-stop racing, and this reliability allowed us to save time and increase our lead.” According to Mickey Miller, driver and co-owner, they completed 560 laps in the race and 100 laps of practice and qualifying on the same StopTech rotors.

After starting the race at 11:00am on Saturday, Bullet Performance took the checkered flag the next day at 12:00pm. StopTech’s front-only World Challenge brake upgrade kit includes two-piece floating directional AeroRotors® with directional AeroHatstm, ST-40 4-piston calipers with patented bolt-in bridge, and StopTech stainless steel brake lines. The team ran Hawk HT-10 track pads in the front and had a third of the pad remaining after the race. The low pad wear evident in this grueling race was a direct result of StopTech's superior AeroRotor design. The tremendous air flow through the patented internal vanes and directional hats allowed the rotors to stay cool enough to keep pad wear to a minimum.

The World Challenge brake upgrade is designed for 55 minute sprint races and the rotor is smaller than the standard StopTech 332x32mm BMW E36/E46 3-Series brake upgrade. Despite the use of the smaller components, the brakes performed flawlessly during the much longer 25-hour enduro event. According to Steve Ruiz, StopTech engineering manager, “this successful result once again shows the benefits of the StopTech AeroRotor® and AeroHat™ design in racing applications.”





Matt Weiss
StopTech

 

Just curious why slotted rotors were chosen instead of regular plain rotors?

 

Slotted rotors are used to increase pad bite and keep the pad surface from "glazing". In the upper ends of pro racing, a different slot pattern may be used for an endurance race as opposed to a sprint race as more slots can also increase pad wear. An endurance rotor may have a few smaller slot patterns spaced further out over the rotor while a sprint rotor may have up to 12 slots running the full width of the rotor face. We use 6 slots as a nice compromise between performance and pad life.

Slots have also shown to be an escape path for gases that can burn out of the pad when it's really heated up. In some cases, the gases can burn off at such a rate they can actually form a boundry between the pad and rotor face, diminishing performance. Most modern pad formulations do not exhibit this "outgassing" to the degree earlier pad types did, and it is really not much of an issue.

I hope that answers your question.

Matt Weiss
StopTech

 

The initial moment of contact of a wet pad onto a wet rotor will usually have a slight delay in the brakes actually reacting. I don't believe releasing and re-applying the brakes would have any better effect than just leaving your foot on the pedal, it just needs a moment to get the water off. Drilled or slotted rotors do give the water a better escape path, providing a quicker response and making for better performance if it really coming down and the brakes are all but immersed. Bottom line is, in adverse conditions; leave yourself extra room for the un-expected no matter what brakes you are running. Even if the brakes do their job, the contact patch between the tire and the asphalt is having the same issues with getting water out of the way. I guess you could think of the slots as having the same effect on the pad as more aggressive grooves on a tire have on the road.

Hope that helps clarify it a bit.

Matt Weiss

As for the STi rotors; we are looking into it, but do not have any delivery date at this time.