Yes to that.
We didn’t run data, but I can say that going to a slightly less aggressive pad on the Miata kept me from locking up an inside-front tire. End result: more confidence because I knew I could better trust the brakes.
Photography by Chris Tropea
One of the biggest weaknesses of our Club Spec Mustang has been the substandard braking performance.
The pads–likely from the discount rack at an auto parts store on the wrong end of town that mostly sells air fresheners that smell like the opposite of murder–along with three working calipers and one “potluck” caliper that would occasionally work to some capacity (but certainly not the desired one) combined to make for dicey laps around the Florida International Rally & Motorsport Park.
Many discoveries were made during our Mustang's baseline laps at the Florida International Rally & Motorsport Park–many of them not good.
Yes, you could occasionally coax one flyer out of the car before fade or inconsistency made things weird again, but the real truth is that we’d never really gotten a baseline time after our suspension improvements.
Why the need for a new baseline? We are going to bolt on the 14-inch front GT500 rotors with matching four-piston Brembo calipers allowed as an option under the class rules. For track work, and based on our experience with Mustang, we feel the extra thermal capacity is needed.
Before the car’s recent trip to the Tire Rack SCCA Time Trials Nationals, though, the Mustang got a brake refresh: fresh Hawk HPS 5.0 pads, fresh Hawk HP660 fluid, fresh stock rotors and four working calipers. For the big show, though, we swapped in track pads: Hawk DTC-60s.
This story isn’t really about how “Hawk brakes are better than used-car-lot terror brakes,” because that’s kind of patronizing to you, the reader, who knows that’s true already. But stabilizing those stock brakes with proper pads and working calipers truly did improve our lap times. Once we install those 14-inch brakes, we’ll have a true measure of the improvements.
Before returning to the FIRM for this latest test, we reinstalled our Hawk DTC-60 pads. The DTC-60 is one of our go-to pads for track work–and even some autocross work on heavier cars or with multiple drivers. They do need a bit of heat to work to their full potential, and low-temp street use can be hard on rotors for extended periods. As pads you’ll swap in for a track weekend, however, they’re fine to get you back and forth to the hotel or out to lunch.
[The do-it-all brake pad | Is there really such a thing?]
Not out to lunch was their performance on track, which was worlds better than the original pads. Again, no surprise here, but even the VBox data agrees with our foot and inner ear on this one.
From the very first brake initiation, we can see more rapid deceleration along with peak longitudinal g forces exceeding 1.0 g. Before, our Mustang struggled to maintain 0.8 g of braking force.
The release portion of the cycle for the FIRM’s Turn 2-3 switchback, seen around the 500-foot mark in the data, shows a nice, smooth climb on the longitudinal acceleration graph back to neutral as well.
When we look at the delta graph–which shows how much our two compared times differ–we can see the difference, and it’s not necessarily under braking but in the ensuing corners and acceleration off those linked corners.
My theory here is the more precise braking and better release characteristics made for a smoother corner entry, which made for better mid-corner performance and, ultimately, a better exit.
So yes, there’s time to be gained simply with the additional stopping force. But there’s also time to be gained by having brakes that allow you to enter corners with more precision and confidence, which will produce gains through those entire corners.
Deceleration curves and g traces are consistently better on the Hawks, particularly entering Turn 4 at 1500 feet and Turn 5 at 2200 feet.
We do see a bit of a bobble under braking at 5500 feet, entering Turn 8, however. This is due in some part to ABS intervention–morning rains left some parts of the track slightly damp, while the entire track was very green. There were still some slippery spots.
On the upside, though, now we’re at least able to brake hard enough to trigger the ABS. Most of our hard braking spots had longitudinal acceleration readings in excess of 1 g, and the bottoms of these g traces were pretty clean, showing solid threshold performance at max decel.
Ultimately, we picked up a little more than half a second with our Hawk pads and fully functional brakes–1:22.15 versus 1:22.68–with a lot of that time coming from improved cornering performance after more confidence-inspiring entries.
We don’t expect the 14-inch GT500 rotors and Brembos to improve that time by much–at least not over a single lap. What we are adding, though, is thermal capacity for longer track sessions and confidence for single laps. Still, more capacity could mean better feel and more confidence, which could easily translate into another tenth or two over a single fast lap.
Now that we have fit the base Club Spec Mustang kit, many of our future improvements will come in the name of confidence and drivability. The clock doesn’t care how you get the speed.
The Mustang’s weakest points now remain twofold: the absolutely smoked differential, which does not limit slip in any definable way, and the god-awful seats, which leave the driver expending a lot of energy and mental capacity just remaining upright and keeping a usable sight picture. Both of these shortcomings are on the docket to get remedied this winter as well.
Yes to that.
We didn’t run data, but I can say that going to a slightly less aggressive pad on the Miata kept me from locking up an inside-front tire. End result: more confidence because I knew I could better trust the brakes.
I recall the conclusion from the GRM review of the Subie BRZ tS was that the brake upgrade was a major factor in the decrease of lap time.
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