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Discussion Starter · #1 ·
Hi guys, I did a few searches, but can't find a similar problem within the forums. I have a 06 Cayman S, and recently found that I have somewhat odd brake wear on my front pads. Both sides of the car have the exact same "odd" wear issues. The outer pads have substantially less pad left than the inner pads on each respective rotor. This is only the case on the front pads. It appears almost like there is a design reason for why this is the case, as both the left and right side are identical, so I don't think there is anything wrong per say.

Any ideas?

Thanks,

VadRad
 

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I have three Brembo equipped cars (an Audi Q7, an Audi TT with Boxster Brembo caliper conversion, and the Cayman S) and all three show slightly more wear on the outside pad than on the inside pad. The difference is not great however. I have nothing scientific to offer as to why it happens. It does allow me to judge remaining pad life by looking at the visible outer pad though as the inner one always has slightly more pad left.
 

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1 theory is heat. Even so it goes against common sense, ask the track guys. Their calipers look nice and bright red on the inside but are discolored to varying degrees on the outside - depending on skill and brake usage ;). Heat can and will have an effect. If you are concerned, just swap sides.

Disclaimer
When I rotate street and track pads I always mark them and then reverse location upon reinstall: i.e L inner to R outer, etc., maintains rotation direction. Haven't experienced an issue yet. Anal and OCD. ;)
 

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Theoretically the wear should be even, since both sides have pistons pushing toward the disk. Assuming the hydraulic force is equal inside/outside (i.e. no proportioning valves, etc.) the wear should be the same.

If there is uneven wear, and it is the same on both the left and right sides of the car, then I have to agree with amdeutsch, it's a heat issue. The inside gets airflow from under the car, but the outside gets heat trapped by the wheel.
 

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Just did mine fronts (2009 Base) over the weekend and saw the same thing. To add a data point or two, I have also had two other Brembo equipped cars that both exhibited the same thing (STi and C6 with Brembo GT BBK).

Cars with floating calipers dont suffer this as much. Every Fixed caliper/floating rotor car I have owned has seen uneven wear.

Porsche, for their part, puts sensors on every pad so its not really a concern. Light pops, check your pads.
 

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It is indeed due to heat but not because there's more cooling on the inside. I used to think this too but was debunked by Darrick Dong from PFC (Director of Motorsports). Under intense brake usage the fixed rotors warp outward on the outside and leads to increased brake pad wear on the outer half. Yes, brake pads wear more on the outside but it is due to rotor warping from intense heat (usually at the track). As noted above, floating rotors do not have this problem (as much).

On a similar note, each individual pad will wear unevenly (one side of pad to the other side). On the front brake pads, they will wear faster on the bottom portion. On rears, wear is faster at the top portion. Why? They wear faster at the leading edge of rotor rotation. As rotors spin (going forward) it's the bottom side of brake pad that takes more beating on the front pads and the top side on rear brakes.

As an intense trackie who changes brake pads out all the time (at least once per DE day), I flip pads around so that thicker pad goes on the outside and the thicker side of pad goes on the bottom for front and on top for rear. May sound confusing but pretty simple once you get the visualization.
 
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It is indeed due to heat but not because there's more cooling on the inside. I used to think this too but was debunked by Darrick Dong from PFC (Director of Motorsports). Under intense brake usage the fixed rotors warp outward on the outside and leads to increased brake pad wear on the outer half. Yes, brake pads wear more on the outside but it is due to rotor warping from intense heat (usually at the track). As noted above, floating rotors do not have this problem (as much).
Bingo! I saw That Performance Friction braking video too. Forgot though. Thanks for the reminder! One piece rotors are kind of bell shaped. When the outer friction disc is really hot and expands it therefore "flares" outward due to it's shape. Makes sense but I still wonder why the outer pad would wear more quickly simply because the rotor has "moved" relative to the caliper. The pads are still pressed equally hard against it by the same amount of hydraulic pressure on both sides. Angled to match the distorted rotor, yes, but that would be mirror imaged on each side. Did that make ANY sense? :)
 

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Discussion Starter · #8 ·
Hey guys, awesome feedback. Seems like normal wear from what I have read here. Good to know. Thanks again!
 
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