Uneven wear with AP Racing Sprint BBK

[CSG Mike]

Can you post a picture of the surface of each pad? Can you also post the inner surface of each rotor?

Easy test: Do the pistons still retract with the same amount of force and/or is there any unusual resistance when you push them in to change pads? If not, chances are youre heating the pads unevenly.

Inner pads typically wear faster than outer pads when you're overheating the system. Based on the wear, and the lack of pedal dance, I'd speculate that you may "trail brake" more into right hand corners; this causes the EBD to work the front left brake more.

I need more pictures to make any more educated guesses.

An alternative, is that perhaps you're too fast for the Sprint kit, and it just isn't enough for your needs; this is why the Endurance kit exists (and why we have it on the CSG BRZ).

[celica73]

Does the drivers side wheel bearing check out OK? I don't know how the AP kit mounts, but is it possible for the caliper to be out of parallel with the rotor (some 4 piston calipers can be shimmed to account for this)

[King Tut]

Originally Posted by gramicci101

Both pads from the driver's side are worn significantly more than both pads on the passenger side though. Would one piston of a four piston caliper cause both pads to wear down that much more?

I was referring more to the taper he was seeing on the one pad.

[ATL BRZ]

Originally Posted by CSG Mike

Can you post a picture of the surface of each pad?

Drivers side XP12 pads. Top is the inside pad, bottom is the outside.




Passengers side pads. Top is the inside pad, bottom is the outside.

Originally Posted by CSG Mike

Can you also post the inner surface of each rotor?

No time to jack the car up and take the wheels off at the moment but I glanced at them yesterday at the track when changing pads and they didn't look any better/worse than the outer surfaces.

Originally Posted by CSG Mike

Easy test: Do the pistons still retract with the same amount of force and/or is there any unusual resistance when you push them in to change pads?

Yes all the pistons go in with the same amount of force. I am using a spent pad backing plate to evenly distribute pressure on the pistons to push them back. It's a significant amount of pressure required and I use a big pair of pliers to help.

Originally Posted by CSG Mike

An alternative, is that perhaps you're too fast for the Sprint kit, and it just isn't enough for your needs; this is why the Endurance kit exists (and why we have it on the CSG BRZ).

My BRZ is NA. The Sprint kit is advertised as sufficient for much heavier, higher power cars. I do brake HARD as you can see in my videos, but I can't imagine that my 200whp 2700 lb car is exceeding the Sprint kit's capacity.

[King Tut]

I doubt you are exceeding the kit's capability. Might be time to get some temp strips and an IR temp gun and get a buddy to check some temps in the hot pits when you come off track especially to see the differences side to side.

[CSG Mike]

Originally Posted by ATL BRZ

My BRZ is NA. The Sprint kit is advertised as sufficient for much heavier, higher power cars. I do brake HARD as you can see in my videos, but I can't imagine that my 200whp 2700 lb car is exceeding the Sprint kit's capacity.

The kit is advertised for average drivers, and you're not an average level driver. I wouldn't discount the possibility.

What do you use for data acquisition? Can you post me a log of your driving?

Specifically, I need (GPS) Speed, Brake pedal pressure, Front left/right wheel speeds, steering angle, and (GPS) Yaw rate.

[ATL BRZ]

Originally Posted by CSG Mike

What do you use for data acquisition? Can you post me a log of your driving?

Specifically, I need (GPS) Speed, Brake pedal pressure, Front left/right wheel speeds, steering angle, and (GPS) Yaw rate.

Still need to nut up and buy an AIM Solo DL. All I have is my GoPro. I quit using Harry's a few events ago because my Nexus 5's GPS is too slow.

[CSG Mike]

Originally Posted by ATL BRZ

Still need to nut up and buy an AIM Solo DL. All I have is my GoPro. I quit using Harry's a few events ago because my Nexus 5's GPS is too slow.

[Sleepless]

What tires and sizes are you running? Trying to gauge the load on the brakes.

[ATL BRZ]

Originally Posted by Sleepless

What tires and sizes are you running? Trying to gauge the load on the brakes.

245/40/17 Bridgestone RE-11A

[Sleepless]

Originally Posted by ATL BRZ

245/40/17 Bridgestone RE-11A

My car is setup reasonably close to yours, on 235/40/17 RE-11As, and likely driven just about as aggressively and I get 4 days on XP12s and over 8 days on the rotors, using stock brakes.

The only significant difference is that I've got the TF brake cooling ducts and I always use the Pedal Dance. I've noticed that using the Pedal Dance significantly reduces ABS activation during trail braking which I'm assuming comes from the deactivation of the brake force distribution. This almost certainly has an effect on brake wear.

If you don't want to have to deal with the dance, there is a box coming to enable/disable it: https://www.facebook.com/86nannycontroller

[ATL BRZ]

Originally Posted by Sleepless

My car is setup reasonably close to yours, on 235/40/17 RE-11As, and likely driven just about as aggressively and I get 4 days on XP12s and over 8 days on the rotors, using stock brakes.

The only significant difference is that I've got the TF brake cooling ducts and I always use the Pedal Dance. I've noticed that using the Pedal Dance significantly reduces ABS activation during trail braking which I'm assuming comes from the deactivation of the brake force distribution. This almost certainly has an effect on brake wear.

If you don't want to have to deal with the dance, there is a box coming to enable/disable it: https://www.facebook.com/86nannycontroller

I used to have the TF brake cooling kit with stock rotors but since the backing plates aren't compatible with the AP BBK I sold it and strapped the GT3 air guides to my control arms to get some (apparently not enough) cooling.

I actually still have an original 86 Nanny in the bag, never got around to installing it. I may send it back to him and wait for the pedal dance device as that's what I really need.

[gramicci101]

Originally Posted by ATL BRZ

I used to have the TF brake cooling kit with stock rotors but since the backing plates aren't compatible with the AP BBK I sold it and strapped the GT3 air guides to my control arms to get some (apparently not enough) cooling.

I've seen cars with NACA ducts under the car to catch air for the front brakes, would it be possible to use something like that to direct air towards the GT3 guides?

Or something like the R32 GTR uses to direct air towards their brake guides?


http://forums.gtrcanada.com/general-...rake-duct.html

If there's a way to pull air from the high pressure at the front of the car and direct it towards your air guides, would that help? It doesn't necessarily need to be physically connected to the brakes by a hose to point air in the right direction.

[wparsons]

Originally Posted by Sleepless

I've noticed that using the Pedal Dance significantly reduces ABS activation during trail braking which I'm assuming comes from the deactivation of the brake force distribution. This almost certainly has an effect on brake wear.

That would be activating the rear brakes most likely though, and unless you're driving on an oval should be pretty even left to right.

Ian, I'd check all the mechanical things again. Is the left wheel harder to turn with the wheel in the air (dragging pad or mis-aligned caliper)? Is it possible the fluid passages in the caliper are partially blocked?