Drilled rotors? Really? You like stress risers and cracks?
Photography by Tim Suddard
At our first track day in our Porsche 997, we began to run out of brakes. Despite Porsche’s reputation for superior stopping performance, the FIRM can be a tough opponent. Blame the mix of tight turns and relatively short straights.
[The Grassroots Motorsports ultimate guide to track car lap times]
Before going back, we’d need to replace our stock, original pads with something a bit more suited for track work.
Changing brake pads on a 997 Porsche is quite straight-forward. You pull a clip off the large pin that secures the calipers in place and then gently drive out a rod with a drift. Once you loosen up the pads by gently prying them out with a large screwdriver, the pin will come out more easily.
You will want to have a spare clip and brake pad wear sensors handy as these are service items that tend to get brittle with the heat of a braking system.
But what pads to install? Every compound presents a compromise–endurance pads for Daytona, for example, might be a little temperamental on the street–but we wanted a compound that could handle a lighter-duty track day yet remain somewhat civil on the street. These pads also needed to be friendly towards the rotors.
After consulting the spider charts and some institutional knowledge, we settled upon Hawk HP+, a compound aimed at the track and autocross market that scores high marks for bite, stopping power and modulation. We ordered part No. HB664N.634 for the fronts ($247 per axle set from Tire Rack) and part No. HB290N.583 for the rears ($139 per axle set from Tire Rack).
We also replaced the rotors with fresh, stock-type ones sourced from Spiker Motorsports–the shop also helped with the job along with the new brake pad wear sensors, this part of the bill ran another $450 or so.
Our final move was to replace the brake fluid. While our car had been well serviced in the past, we didn’t know what brake fluid had been used.
We needed something with enough temperature capacity for track day and settled on Wilwood EXP600 Plus: 626-degree dry boiling point along 417 degrees wet. A 16.9-ounce bottle retails for $24.79.
Now we could bed in our new pads. This should be done in a safe place by performing six to eight partial stops from about 60 mph down to about 10 mph. Click here for a brake engineer’s more detailed bedding-in regimen.
Now that our Porsche had fresh brakes, we could now test those new Bridgestone Potenza RE-71RS tires on Apex wheels.
Drilled rotors? Really? You like stress risers and cracks?
Welcome to the thrill of Porsche ownership! Tim's a restorer at heart, and just couldn't bring himself to put the wrong rotors on the car. It's been interesting watching him balance the desire to keep this car original and perfect with his desire to thrash it on track.
Andy Hollis said:Drilled rotors? Really? You like stress risers and cracks?
Cheap Chinese rockauto blank rotors ftw!
Andy Hollis said:Drilled rotors? Really? You like stress risers and cracks?
No worries...I expect the Hawk HP+ pads will have significant fade before reaching very high temperatures and thus not thermally crack the rotors 
fusion66 said:No worries...I expect the Hawk HP+ pads will have significant fade before reaching very high temperatures and thus not thermally crack the rotors
Yeah, I tried HP+ once and decided they were the worst of both worlds. All the noise and dust of a true race pad, but none of the high temp capacity... :)
I have pretty limited experience with these pads on track on this car, and it was under less than ideal conditions, but I can say they have really good initial bite for a pad that can also get you to and from the track. But, yeah, they're messy.
I'm actually a big fan of Hawk's Street/Race compound, which we used on the S197 Mustang project. They're also filthy, as most Hawk pads are, but they make up for it my being a pad that excels at both low and high-speed competition, so long as you aren't running tons of laps back to back.
I'm curious to see what kind of rotor wear Tim gets from the HP+. That's really the rub with any truly good pad, is how quick do they grind up the rotors. If these can sustain the rotors, while providing enough capacity for the few track laps he's even going to need them for, maybe the dirt is worth putting up with.
HP+ won't eat rotors in a few trackdays but you may find sessions at The FIRM limited by brake fade. I like HP+ as a good pad for someone who just caught the bug, bought a CAI and some pads and is going back. For serious work, Hawk DTC and Carbotech have much better temp range. HPS is a good DD pad, better modulation and bite than parts store pads for not that much more, in the grand scheme that is.
I have tried to use the Hawk HP + before as a one and done dual purpose use pads. But they are simply too noisy and way too freaking dirty for street use and not capable truly enough on the road course either. Basically had to "late brake" to make them work right and minimize the grinding noise on the street and would still got lots of disapproving looks at intersections. I would consider them as an autocross use pad. I have used the Hawk HPS pads for my toy's street driving and on most of the daily drivers. In the past I would typically switch out the toy's pads to Hawk Blue front and Hawk Black in the rear or (Carbotech XP-10 front and XP-08 rear) for road course duty. I am sure there are newer pad materials now that maybe better.
BTW, what are those crazy, what appears to be ceramic rollers for on the stock pads?!?
deaconblue said:BTW, what are those crazy, what appears to be ceramic rollers for on the stock pads?!?
Mass dampers for NVH reduction. The other downside to drilled rotors is they tend to make a lot of noise.
Agreed that HP+ are a good upgrade for a first-timer. When I was going through my 2 years of HPDE's with a nearly stock RX-8, they worked great for me. But now that I can get everything out of a car, they won't last for me. Hell, it's hard to get a stock-ish car to get tires to last, either, so it's all relative.
I LOVE Hawk's High Performance Street 5.0 pads for my road cars and I think a beginner could get by on them for their first few HPDE's, as well.
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