I’ve been using the new Black Magic “JK Front Very Large Brake Kit” for several weeks and thought I’d share my observations:
Background: My jeep is a TJ with JK Rubicon axle’s front and rear. It’s has a frame stretch, 3 link front, triangulated 4 link rear. You can read details in my profile, but the key point is its running JK axles, axle shafts, and brakes. They are turning/stopping 37” Goodyear MTR’s on Raceline beedlocks (approx. 115 lbs per corner).
First Brakes: As part of the build that included the JK axles and 37” tires, we installed the only JK brake upgrade on the market (this was early 2011), the Teraflex “JK Big Brake Kit”. The kit looked impressive: dual piston calipers, 13+” rotors, and fresh pads. We also installed a larger bore master cylinder, per Teraflex recommendation.
I was unimpressed with the braking performance. It wasn’t terrible, but was about on par with how my TJ previously had performed with 33” tires and completely stock brakes. It did stop (wasn’t a disaster waiting to happen), but didn’t provide a lot of confidence.
2’d Brakes: After about year, I tried a prototype set of brakes that used OEM calipers (single piston), a 13” rotor, and Black Magic pads (a custom bracket positioned the OEM calipers properly for the oversized rotors).
This new setup provided a clear improvement over the first kit. Once broken in (which all pads need), I did have reasonable braking in a panic situation. I now had more confidence. But they still weren’t what I’d call impressive. Blaine, the prototype designer, kept asking for feedback. All I could say was “they are better than before, now they are ok”. This combination was never marketed. By looking at the components, it’s similar to the “Road Race” kit (which I haven’t used).
3’d Brakes: Blaine called about 2 months ago and said he’d finally traced down the suppliers to assemble what he hoped would be a bolt-in JK kit that he could stand behind. He installed it and I’ve been driving now for approx. 6 weeks. This is now in limited release as the "JK Front Very Large Brake Kit” (link below).
This setup exceeds braking performance on anything I’ve previously had with any configuration of brakes and tires (i.e. stock brakes and 30” tires, EBC yellow stuff pads and 33’s, Teraflex kit and 37’s, etc.). Once broken in, I have easy stopping in normal situations and plenty of reserve stopping in panic situations.
One way to describe them is via panic stop testing. I’d get up to 50 – 55 mph and stomp on the brakes. I’d go into a full skid. This was not my intent and I’d immediately release a little pressure to make it a more controlled stop. My point is I could now control the stop to what ever rate of braking I wanted. With either of the previous brakes, a “full stomp” would result in decent braking, but not something that needed to be controlled or modulated. BTW – my TJ doesn’t have ABS. I’d imagine a JK with these brakes and ABS would be very impressive.
Bottom line – this Black Magic kit is the only JK braking solution I’ve tried that I can call impressive.