AP Racing "Sprint" BBK long term update

[CSG Mike]

We've had the BBK on for around 29k miles of mixed street and track driving. We've also gone through 2.5 sets of tires on them, but keep in mind that most of the driving on the BRZ was in spurts of 1-2 hot laps at a time for data collection rather than full sessions, and spirited canyon runs, so it's a LOT of heat cycles.

In terms of brake pad, we went through around a 1/2 set of AP Racing C300 C300 (~7mm), a full set of Carbotech XP12 (15mm), and 1/2 set of Project Mu Racing 999 (~7mm). Additionally, we went through about 1mm of street pad (Carbotech 1521). Also, we ran NO ducting, which is testement to the sheer capability of this setup.

The microfractures on the inner edges have been there a while, and we've been keeping an eye on them, but they haven't propagated past the vanes. Essentially, they LOOK bad, but have zero effect on braking or brake pedal feel for street and track driving.

FYI, the inner edges of the rotors also have J-hooks. We just wore completely THROUGH them.


We're currently running a special on this setup, please PM @CounterSpace Garage for pricing, details, wheel fitment, and application questions. If you need pad recommendations, feel free to PM either myself or @CounterSpace Garage.

Now, on to the pictures.

Inner side of the rotors; you can see the cracks, and the J-hooks are completely worn off. You can also see heat checking/microfractures if you look closely.


Compare the thicknesses of the inner and outer edges...



The front J-hooks are nearly worn down. The heat checking is much more visible on this side.



Front and back of the rotors

[Anthonytpt]

Wow such amaze! Much brake! Doge want.

[s2d4]

@CSG Mike

What would your take be on the uneven wear? as in why it happened and prevention?

[OrbitalEllipses]

Originally Posted by s2d4

@CSG Mike

What would your take be on the uneven wear? as in why it happened and prevention?

It has to do with physics.

[ZionsWrath]

Originally Posted by Anthonytpt

Wow such amaze! Much brake! Doge want.

ww

[Calum]

Originally Posted by OrbitalEllipses

It has to do with physics.

Wow, really. And here I thought it was astrology.... It's monday where you live isn't it?

My first guess is the uneven wear is caused by, IIRC, the lack of piston seals in this kit. I'm sure we'd all like to hear what Mike or David have to say about it though.

[CSG Mike]

Originally Posted by s2d4

@CSG Mike

What would your take be on the uneven wear? as in why it happened and prevention?

I'd suspect the inner side is hotter since there's less heat sinking (the hat) and less airflow than the outer edge.

Ducting will likely mitigate most, if not all of this.

We're watching @ImperiousRex's car for this, as he has the same setup, but with ducts.

We run a similar setup on our S2k, and we're keeping an eye on that as well.

[s2d4]

Originally Posted by CSG Mike

I'd suspect the inner side is hotter since there's less heat sinking (the hat) and less airflow than the outer edge.

Ducting will likely mitigate most, if not all of this.

We're watching @ImperiousRex's car for this, as he has the same setup, but with ducts.

We run a similar setup on our S2k, and we're keeping an eye on that as well.

Thanks for the reply, people have had ducting worries of uneven wear of cooling only inner side.

If this checks out, it may be that the ducting will actually reduce the uneven wear.

[OrbitalEllipses]

Originally Posted by Calum

Wow, really. And here I thought it was astrology.... It's monday where you live isn't it?

My first guess is the uneven wear is caused by, IIRC, the lack of piston seals in this kit. I'm sure we'd all like to hear what Mike or David have to say about it though.

Oh you.



trollface.jpg

[AceHeader-MT]

Originally Posted by CSG Mike

I'd suspect the inner side is hotter since there's less heat sinking (the hat) and less airflow than the outer edge.

Ducting will likely mitigate most, if not all of this.

We're watching @ImperiousRex's car for this, as he has the same setup, but with ducts.

We run a similar setup on our S2k, and we're keeping an eye on that as well.

I have the APR inner ducting with AP spring kit both order from CSG. I will see mine after long term test.

[smbstyle]

Other than stopping power, didn't someone talk about the benefits of cheaper pads/rotors and longer lasting pads/rotors before? (can't remember which thread).

Can you elaborate on this?

Currently running OEM setup with the TF Brake Cooling kit; front pads are lasting around 6 total track days ($180 a set) and OEM-based rotors are lasting around 6 days as well ($90 a set). Looks like I'll get about a years worth of events with the rear pads. I'm fine with the braking capabilities of my setup, just curious of long term costs vs. BBK initial cost and long term expense.

[solidONE]

you guys murdered those brakes... lol

[OrbitalEllipses]

Originally Posted by smbstyle

Other than stopping power, didn't someone talk about the benefits of cheaper pads/rotors and longer lasting pads/rotors before? (can't remember which thread).

Can you elaborate on this?

Currently running OEM setup with the TF Brake Cooling kit; front pads are lasting around 6 total track days ($180 a set) and OEM-based rotors are lasting around 6 days as well ($90 a set). Looks like I'll get about a years worth of events with the rear pads. I'm fine with the braking capabilities of my setup, just curious of long term costs vs. BBK initial cost and long term expense.

Two front rotors for $90? That seems unbelievably cheap, even for a basic Centric rotor. It's pretty scientific with regard to the consumables cost: the pads are thicker, so there's more to use with less often time to replace.

Have you read @JRitt's technical posts about the Essex kits?

[smbstyle]

Originally Posted by OrbitalEllipses

Two front rotors for $90? That seems unbelievably cheap, even for a basic Centric rotor. It's pretty scientific with regard to the consumables cost: the pads are thicker, so there's more to use with less often time to replace.

Have you read @JRitt's technical posts about the Essex kits?

Yep, $90 for two front Centric blanks, after two days I noticed a little bit less heat checking than I got with the OEM rotors, so I'm thinking they might last even longer than the stock ones. And in terms of actual wear (thickness), I measured 0.948" new, and after 2 days at Sebring, I measured the exact same thickness.

Nope, haven't read any of his technical posts.

I have only really looked into the Wilwood SL6 front kit, and found the replacement rotors to be about $170 each, which even if they last twice or 3 times as long, it still isn't worth it. And looking at the pads for the Wilwood SL6, they are only $40 to $50 cheaper than the OEM based pads.