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Came across this online. Looks like some companies in Thailand are retrofitting electronic parking calipers to aftermarket BBKs. These are not solutions provided by Endless or Brembo. Does anyone recognize these electronic calipers?
All you have to do is make a caliper mount that spaces it properly. Nobody makes a kit anymore because the actual demand is really low, and every rear brake upgrade option would need its own adaptor.
Better to just get the Sakebomb rear kit that re-uses the OEM caliper
For what it's worth, the rear caliper on the bigger RS / RZ / Spirit R variants in Japan with the 314mm rotors is basically unchanged from the 294mm rotor versions. Only the bracket differs to space the caliper out to suit the bigger diameter rotor. The piston and pad size is also unchanged going all the way back to the series 3 RX-7 (84-85 GSL-SE brakes).
With the weight distribution of an RX-7 not much rear braking is required. Since the very first disc brake rx7s, Mazda's engineers have generally taken the view of adopting the same size rotor front and rear. Increasing the rear rotor size to match the front and spacing out the caliper seems the way to go. The rear rotor is still the same relatively thin 20mm thickness all the way from 1984 to 2002 - only the diameter increases - even when the big brake late models adopted a 314mm x 32mm front rotor they kept the rear to 314x20.
If you have aftermarket calipers with bigger pistons at the front than the factory 4 piston calipers, you will increase front braking torque again, which may throw out front:rear bias, but this can be somewhat mitigated with an adjustable proportioning valve. If you try to upsize the rear calipers, you run a risk of locking up the rears too early and that is a much bigger (and more dangerous) problem than being too biased to the front.
Yup, even the RS/RZ caliper is the same caliper with a longer bracket.
Thing is with the stocks, they limit what you can do up front without throwing the bias far forward, and the pads themselves are TINY (which exacerbates the balance) and not available in a lot of good compounds anymore. And the calipers are old, and tough to get rebuilt well, and prone to failure on track. I personally roll to the track with a spare set every time. And on top of it, you can't go thicker on the rotor ring and they look shitty to boot.
I'm dying for an upgrade rear that also uses a fixes caliper you can just easily slide the pads in and out of, and not have to finagle all the shims, springs, and slide plates that all fall out in a pile when you pull them out. But, somebody needs to make parking brake option that isn't a million dollars. Track guys would buy em, I know everyone who tracks knows what I'm talking about.
I run stock brakes, since none of my tracks are particularly fast, but I would have a much harder time working on the car by myself without parking brakes.
You can't jack a lowered FD up on all four wheels without ramps, and you need the handbrake to stop the car when you roll it off the ramps.
.Thing is with the stocks, they limit what you can do up front without throwing the bias far forward, and the pads themselves are TINY (which exacerbates the balance) and not available in a lot of good compounds anymore. the calipers are old, and tough to get rebuilt well, and prone to failure on track. I personally roll to the track with a spare set every time. And on top of it, you can't go thicker on the rotor ring and they look shitty to boot.
Pad size does not affect brake bias. Brake piston size, effective diameter, pressure, and pad Mu (coefficient of friction) does.
I don't know about all that. Most of the brake bias calculators I've seen factor the pad area, and logic would back that up. I understand the technical/definitional distinction, but in practice a brake pad the size of a pencil eraser isn't going to work the same as one the size of a kitchen sponge.
I don't know about all that. Most of the brake bias calculators I've seen factor the pad area, and logic would back that up. I understand the technical/definitional distinction, but in practice a brake pad the size of a pencil eraser isn't going to work the same as one the size of a kitchen sponge.
I do know about all of that Brake bias calculators don't care about the "pad area" (surface area or volume) of a pad. The only thing that matters is the height of the pad, which determines the effective radius of the brake system.
If you have a 2" tall pad on a 13" rotor, the effective radius of the force of the caliper pistons is 12". If you now install a 3" tall pad on the same 13" rotor (assuming the annulus of the rotor could fit it), the effective radius has been reduced by 0.5" and is now 11.5" -which changes and reduces the brake bias on that end of the car. Even though the caliper pistons didn't move and the same rotor is used, the bias has now changed.
I understand your eraser vs sponge analogy, but that would be explained by the eraser being smaller than the piston acting on it. The brake pad must be at a minimum, the size of the piston acting on it. Any additional volume and surface area of the brake pad increases longevity and thermal capacity, which has no effect on the total braking force of the system (unless the height is changed as mentioned above).
0.02
Last edited by Billj747; Oct 11, 2024 at 11:22 AM.
I think it's best to give up on that kit and never use it. A convoluted design with multiple (unnecessary) potential failure points that I wouldn't use anywhere on the car, let alone the most critical component (e-brake caliper).
I took it as a sign from the rotary gods, be ashamed after owning an fd for 18 years and went out for this.
honestly just wanted it for crazy hills in SF.
I didn’t see it mentioned but my company is a vendor for Ceika and they make bbk kits that utalize factory style E brake options (ie cable on caliper) pricing is very competitive, they are fully customizable, and good quality.
I didn’t see it mentioned but my company is a vendor for Ceika and they make bbk kits that utalize factory style E brake options (ie cable on caliper) pricing is very competitive, they are fully customizable, and good quality.
Just about 2k for the rear only. But I guess you are getting a custom kit to work with your car.. sucks for those who need all 4 🤷
I didn’t see it mentioned but my company is a vendor for Ceika and they make bbk kits that utalize factory style E brake options (ie cable on caliper) pricing is very competitive, they are fully customizable, and good quality.
Brake bias calculators don't care about the "pad area" (surface area or volume) of a pad. The only thing that matters is the height of the pad, which determines the effective radius of the brake system.
