Uneven Pad Wear

[No Crust Racing]

Hey guys, attached are some pics of my front driver side pads that came out of an S13 Silvia (CA18). I’ll detail the setup and my questions below.

PADS are QFM A1RM

Car has only 165rwkw and runs around 1:43 around Winton.

Runs Federal 595 RS-R Rubber (235 R17s)

Runs TRW Lucas 600 Fluid

Runs RDA Slotted/Ventilated Rotors up front, solid slotted rears

Runs S15 calipers up front, standard rear

Runs R32 GT-R Master Cylinder

Standard brake lines

Pads have done about 5 track days, 1 drift day, and 2 DECA days and very minimal street driving. All up under 2500ks total.

Why would only the inner driver side pad wear like this? The passenger side pads show wear similar to the outer pad from the driver side and appear to have some meat left. Rear pads are fine.

There’s clearly something amiss here to have that much difference in pad wear from the inner to outer pad, as well as such different pad wear side to side as the passenger side shows even wear inner to outer pad.

Thoughts?

[djr81]

The trailing edge of the inside pad is where they get the hottest - and heat means wear. So that explains why the inner pads wear faster than the outer pads. Why you have a side to side difference is anyones guess.

[Marlin]

Firstly, you got MAX life out of them, they're rooted! lol

How are your wheel bearings? The hub moving under load in turn causes one pad to contact, causing wear.

Also, your calipers probably need a clean up and some new seals thrown through them, you could well have one piston thats a bit stickier than the other.

[No Crust Racing]

I'm chatting with Greg from QFM about thisalso, he also asked about the wheel bearings. Can I test them easily?

I might look into a seal kit, they were second hand when I got them and have been abused since.

[Marlin]

Bolt a wheel on it, and with it jacked up hold the tyre top and bottom (try and wobble it), feeling for play. If you feel any, she's cactus.

[No Crust Racing]

Ahh yes that's right, it's been 3000k's of track time since I did that last and she's an old bus so worth me doing it again.

[badhairdave]

Heat.

Turbo silvias have a big vent for the intercooler on the front left and no vent on the right so your right inner pad is probably getting hotter than the inner left.

The pad is still wearing fairly evenly though it's a bit hard to say for certain when they are that low because they tend to fall apart...

[No Crust Racing]

I've cut slots into the inner guard on the right side as well as I noticed that difference.

However the right side has my oil cooler so hot air could be flowing through. Might be worth making up some basic deflectors for the LCAs

[scooby36]

noticed those QFMS fell apart pretty badly when they got below 4mm for me

[No Crust Racing]

Further to this, pulled the rotors to have them machined. Noticed that the side that had worse pad wear also has noticable more rotor wear, to the point where the slots on the inner side of the rotor looked fairly wiped and may not come good with a machine.

Still sound like a heat issue? I couldn't detect any deflection in the wheel bearing but I note the tie rod ends dust boots are split.