“As much as I’d love to tell someone there’s one brake pad that can do everything, the reality is when you’re trying to compete in multiple venues, you’re going to have to weigh compromises when it comes to brake pads.” That’s Hawk Performance’s Mitch Bloom lamenting the bane of the brake market the world over: the search for the do-it-all pad.
“There’s just so many considerations when it comes to choosing a pad, and what makes it even more complex is that the right pad for your driving style might not be the right one for my driving style,” he continues. “So even once you find your solution, that solution might not be universal.”
But that doesn’t mean all hope is lost. When we discussed with Bloom the importance of choosing the right pads, he emphasized how the search for the right pad is a process, not a product. “I can probably recommend a good starting point just based on use case and popularity, and most of the time that will probably be the right call,” he explains, “but with brake pads, you always have to be willing to experiment and rethink a bit.”
When speccing a pad, Bloom starts with the hard data, like a car’s weight and power. And remember, power is a huge part of the equation, as the kinetic energy that brakes must transform into heat energy increases with the square of the speed of the car. That means a 3000-pound car going 80 mph is carrying nearly double the kinetic energy of the same car going 60 mph, even though the speed is only 33% faster.
“Other factors are going to play a big part in the decision as well,” he continues. “For example, prototype cars on slicks–particularly very light ones–usually don’t want a very high-friction pad.” The grip delta on slicks from cold to warm to hot can be extreme, and when aero loads–which are particularly strong at higher speeds–are factored in, an overly aggressive pad can end up being difficult to drive and modulate as those tire loads vary so much because of the transfer from aero grip to mechanical grip.
“Likewise, something like a Spec Miata won’t like too aggressive of a pad,” he notes. “They’re light, have narrow tires and not a ton of grip, relatively speaking. So it’s very easy to ‘over-pad’ them and end up with a lot of lockup and modulation issues.”
Then what’s the best all-around pad? One that’s drivable on the street but also performs great on track or at an autocross? And it lasts forever and doesn’t make a lot of dust?
“It doesn’t exist,” Bloom replies. “It’s what every brake company wishes they could invent, but the physical limitations just don’t allow it to exist. So what you need to do is figure out where you’re willing to make the compromises.”
For most of Hawk’s autocross customers, Bloom recommends they start with something like a DTC 30 or an HPS 5.0 compound. “You really have to look at how the cars are being used,” he explains. “For most people, it’s going to be something they’re autocrossing, maybe even competitively, then taking to the track once in a while.
“Ideally,” he continues, “you’d want a dedicated set of pads and rotors for each venue, but for the folks that don’t want to switch pads, we make sure they know that they might be giving up some ultimate thermal capacity in a track situation. So you may get three or four laps, then start to notice some minor pad fade that you have to manage.
“The flip side there is if someone wants a pad with endless reserves on track, you’re talking about a pad that’s comfortable operating upwards of 1400° F peak temperatures lap after lap. And that’s completely available, but the tradeoff is at lower temperatures, that pad is not going to produce ideal driving characteristics or street-ability–and it’s going to eat rotors.”
The life of a brake supplier can be frustrating. Your customers tend to want all their groceries in one bag, but they don’t want that bag to be heavy.
So Bloom is constantly preaching the approach of compromise when it comes to switching back and forth between low- and high-temperature venues or, even better, multiple sets of pads/rotors.
“The best-case scenario is going to be having a set of pads/rotors for street and autocross and one for track use, unless you’re just doing single hot laps like a Time Trial or something,” he explains. “If you’re on track long enough to get real heat into the pads, your best bet is going to be having a set of pads and rotors that is comfortable at those temperatures.”
He feels that even if you’re switching pads at home and driving the track pads to the venue, that minor bit of additional rotor wear won’t be as bad as the accelerated wear and behind-the-wheel frustration of trying to keep low-temp pads alive on track for extended sessions.
We’ve said before–and will continue saying until the sun explodes–that your brakes are the most powerful speed-changing device on your car. Therefore, they should be treated as a key component to a fast lap, not an afterthought.
If you’re looking for a one-size-fits-all solution, you’re probably leaving time on the table. At best you can probably find a one-size-fits-most compromise, then be prepared to accept the areas where the pads are working out of their field.
We talked to SCCA Solo, Holley LS/Ford/Mopar Fest and time trial champ Justin Peachey about his approach to brakes as a weapon for slaying the clock, and he reiterated the importance of finding the right setup.
“People are very quick to think they need bigger brakes, when frequently choosing the right compound will make a drastic improvement,” Peachey says. “Good brakes are about so much more than just being able to brake later. The real key to using your brakes effectively is having something you can modulate effectively into a corner and during the cornering phase to balance the chassis to keep the tires on the limit of adhesion. Any time your tires aren’t operating at the limit, you’re losing time.”
And the ability to do this doesn’t always mean the same pad for everyone, even in different situations. “I’d love to be able to sell you a brake pad that does absolutely everything,” Bloom says, “but the best I can do is offer some different choices, knowing that one of them is going to be perfect for what you’re doing with it and how you’re driving it. And Myself and our Tech Team are always happy to help you figure out which one that is.”
Comments
PT_SHO
New Reader
10/6/23 1:48 p.m.
I autocross a lot and once a year one of the chapters has an "enduro", a five laps event. That is the most severe usage my brakes get. At one of those events, with a layout that had a lot of longer pulls, I ended up with some brake smoking as I pulled off, but a slow idle around the parking lot for a few minutes cooled things off nicely.
The car builder liked Hawks, think it was HP-1, or HP+, unsure? In 2006. The car is my daily, and the heavy dusting and squeaking make me rethink that choice once the rotors got too thin, after the second set of pads. I also didn't like that those Hawks really needed a little bit of heat, one or two good applications, before they really gripped. Not optimal for street use - I had a set of even more track-ish pads on another car and nearly rear ended someone when the onramp backed up, and I was STANDING on those brakes with little effect. So I went back to Carbotech 1521's "high performance street compound", used to be called their Bobcat line. No change in grip from cold to quite warm, far less dusting, pretty much no squeal, and the lower torque offers me more range of modulation. Like most makers, if you want to go to a more aggressive pad for track days, they offer higher temp pads with a compatible compound so that you supposedly do not have to grind them clean and re-bed the pads. And these have lasted in one set as long as two sets of those Hawks did, with plenty of pad still left. It's worked for me.
edmagoo
New Reader
10/6/23 6:14 p.m.
OK, I know the correct thing to do is marry a set of pads to a set of rotors but how bad is it if you keep the same rotors you drove to the track on and change just the pads for a track session?
I've been street driving my civic for almost a year with Carbotech AX6 autocross pads. They've worn down the front rotors, so I'm going to swap on some used ones tomorrow for the track sprint on Sunday.
The replacement rotors were used with some Hawk HPS pads, so I sanded to bare steel with some 150 grit.
edmagoo said:
OK, I know the correct thing to do is marry a set of pads to a set of rotors but how bad is it if you keep the same rotors you drove to the track on and change just the pads for a track session?
That depends on the pads involved, if they're both from the same manufacturer, often they'll publish which pads have compatible compounds. If you're switching between incompatible compounds you'll probably notice rapid rotor wear and/or a big reduction in braking performance when you switch.
Here's my luck with dual-duty pads so far:
EBC Yellowstuff on AE92 Corolla:
- Pros: Totally unflappable on track, not bad on the street, last a long time, affordable
- Cons: Braking power that ramps up rapidly with temperature on street or in autocross, fairly high dust, need to be mindful of rotor heat because these pads can destroy a set without making a peep.
Powerstop PST on Toyobaru:
- Pros: Great street manners even at freezing temps, affordable
- Cons: Wear quickly, very dusty, not really fit for track use - performed decently but wore away roughly all pad material and caused heavy rotor wear on the first track day, even with brake venting.
Powerstop PSA on Toyobaru:
- Pros: Great street manners even at freezing temps, affordable
- Cons: Wear quickly, threaten to blot out the sun with dust, can still get some fade on long track sessions even with venting, not easy on rotors.
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