COTA Track Day

[e82n54]

I got to drive Circuit of the Americas so I thought I'd share my experience. It was a blast! I loved it. The track is hard on brakes so my setup was inadequate, but I still had fun. I just had to brake in stages at turn 12 to keep from overheating the brakes. The car actually warned me many times that I was braking too hard. I've never seen that before. I had no chance on the straights compared to the higher horsepower cars in the group, but I kept up well in the corners. What a fun day.

Track setup:
Vorshlag Camber Plates
TRMotorsport wheels 17x8.5J ET40
Hankook RS3 245/40/17
Stoptech Street Perfomance front brake pads
Titanium shims
Brake fluid - Castrol SRF
Brake pedal rubber pads: part #35211160422 $4.47 - stacked 2 more for track use only

[e82n54]

video should be working now... Merry Christmas everyone!!!

[Mach1er]

Awesome! I hope I can do that one day. BMW PDS comes first in the Spring...

[joeo]

Love the foot cam.
If the warning light that you're getting is a yellow brake light - that means that the 'hill-holder feature' has been disabled. It does happen when one uses the brakes hard on track, but I've just ignored it.
What pads are you using?

-Joe

[e82n54]

The warning light I got was on the iDrive. The car would make a warning gong sound and display a message over the entire screen stating something like 'brake system overload' and 'drive moderately'. It was pretty distracting at first until I realized it didn't affect the car like limp mode would so I just learned to ignore the screen after a few warnings. I just tried to use the brakes less aggressively.

Front brake pads were Stoptech Street Perfomance. They were recommended by Harold at HP Autowerks as a compromise between street and track. They have a more linear bite as brake pedal pressure increases so they're easier to modulate. A track obviously would have been better.

[3002 tii]

How much camber are you running? Do you need to run spacers for that wheel and tire combo? Fenders rolled?

Nice heel toe action btw

[joeo]

Here's my experience with brakes. I've tried DTC60s, DTC 70s, Hawk HT-10s, and PFCs. My current setup, which seems to provide the very good braking *and* longevity is with PFC pads up front and DTC60s in the back. The DTC60s in front provides the best braking IMO; but they don't last long. The PFCs last a lot longer and provide very good braking performance. I have not tried running PFCs in the back yet.

I've come up with some ducting for the front brakes that I believe helps to prolong pad life and reduce uneven wear. I was having an issue where the front pads would wear very unevenly. My thought is that there was localized boiling of the fluid behind some of the pistons, but not others; resulting in very uneven pad wear (only on the front). With the ducting in place, Motul fluid, and the PFC pads, I've had even pad wear. I don't, however, have any solution to stop the dust boots from melting away or the seals from going. I think the only answer is to rebuild the calipers every n track events, or go with different calipers.

Braking is one of those things that is a big (and fun!) challenge (at least for me) to get right. I want to use the maximum braking at the right time to optimize trail braking/turn in, and, well, get around the track as fast as possible. I kinda see the BMW as a tool to learn how to drive better and get around the track faster. Having to rebuild the calipers is just part of keeping that tool working correctly and safely.

I want a foot camera.


-Joe

[e82n54]

Originally Posted by 3002 tii

How much camber are you running? Do you need to run spacers for that wheel and tire combo? Fenders rolled?

Nice heel toe action btw

Thanks. I'm so sad the manual transmission is slowly going away. I know it's not as fast, but it's just more fun.

-2.4 degrees camber (all suspension is stock except the vorshlag camber plates)
no spacers
fenders aren't rolled
no rubbing
I use a square setup so I can rotate wheels front to back. Tire wear is even. I feel like it's a nice balance on track too.

[jsublime]

awesome vid, thanks for sharing

[e82n54]

Originally Posted by joeo

Here's my experience with brakes. I've tried DTC60s, DTC 70s, Hawk HT-10s, and PFCs. My current setup, which seems to provide the very good braking *and* longevity is with PFC pads up front and DTC60s in the back. The DTC60s in front provides the best braking IMO; but they don't last long. The PFCs last a lot longer and provide very good braking performance. I have not tried running PFCs in the back yet.

I've come up with some ducting for the front brakes that I believe helps to prolong pad life and reduce uneven wear. I was having an issue where the front pads would wear very unevenly. My thought is that there was localized boiling of the fluid behind some of the pistons, but not others; resulting in very uneven pad wear (only on the front). With the ducting in place, Motul fluid, and the PFC pads, I've had even pad wear. I don't, however, have any solution to stop the dust boots from melting away or the seals from going. I think the only answer is to rebuild the calipers every n track events, or go with different calipers.

Braking is one of those things that is a big (and fun!) challenge (at least for me) to get right. I want to use the maximum braking at the right time to optimize trail braking/turn in, and, well, get around the track as fast as possible. I kinda see the BMW as a tool to learn how to drive better and get around the track faster. Having to rebuild the calipers is just part of keeping that tool working correctly and safely.

I want a foot camera.


-Joe

Thanks for your insight. I need to replace my pads now so I'll have to look into other options. I'd like a pad that can handle more heat, but I don't want to create a dangerous situation on the street if the pad is too cold. It's a dilemma. Ducting would be cool, but I can't spend time on that now.

[hoki06]

Originally Posted by e82n54

Thanks for your insight. I need to replace my pads now so I'll have to look into other options. I'd like a pad that can handle more heat, but I don't want to create a dangerous situation on the street if the pad is too cold. It's a dilemma. Ducting would be cool, but I can't spend time on that now.

Do yourself a favor and buy track only pads/rotors. If you try to use one pad for street and track you'll make compromises in both environments. Street pads aren't designed to see track temps and track pads aren't designed to work at low street temps. While track pads can work on the street, the abrasive compounds will cause premature rotor wear and will remove the transfer layer from the rotor causing poor performance.

Swapping rotors and pads isn't that much more to add to your track prep list and it's the right thing to do. Cheap rotors from Advance Auto are perfectly fine, don't get anything fancy unless you have money to burn.

[e82n54]

Originally Posted by hoki06

Do yourself a favor and buy track only pads/rotors. If you try to use one pad for street and track you'll make compromises in both environments. Street pads aren't designed to see track temps and track pads aren't designed to work at low street temps. While track pads can work on the street, the abrasive compounds will cause premature rotor wear and will remove the transfer layer from the rotor causing poor performance.

Swapping rotors and pads isn't that much more to add to your track prep list and it's the right thing to do. Cheap rotors from Advance Auto are perfectly fine, don't get anything fancy unless you have money to burn.

I'd like to do that, but I'm so slow at doing the brake job. How long does it take you to change the pads and rotors (front only I assume)?

[hoki06]

Originally Posted by e82n54

I'd like to do that, but I'm so slow at doing the brake job. How long does it take you to change the pads and rotors (front only I assume)?

Once you do it a couple times it becomes very quick. You'll memorize the tools needed and procedure for doing the swap. When my E36 M3 was street and track, it would take less than an hour to swap front and rear rotors/pads. I even bought extra sets of the tools I needed and had a small bag with those tools specifically for pad/rotor swaps.