New DBA rear rotors

After 8 years of hard track day driving, the rear rotors on the Z cracked at the last track day in October 2019.

I have replaced them with another pair of DBA 4000's, this time with the newer T3 slot design. 

Thank you to Michael at Autosphere for setting me up with these.

Rear DBA rotor temperatures

The DBA rotors have three coloured stripes on the edge that change colour when they reach a certain temperature.

Temperature (degrees C)/Original colour/New colour:

• 458 / Green / White
• 550 / Orange / Yellow
• 630 / Red / White

Upon inspection of the rear rotors today, I found the following:

Left hand side - only the green stripe had turned white, orange and red unchanged.

Right hand side - green stripe had turned white, orange stripe had partially turned yellow and red was unchanged.

So far these rotors have done one track day at Phillip Island and one at Sandown - both tracks are high speed and run anti-clockwise. Whether track direction causes more brake usage on one side is still a question I need to find an answer for.

Project μ SCR-Pro Front Rotors

Since my last set of DBA 4000 rotors had cracked, I decided to try something different to test their durability during track use. I compared prices for the DBA 5000 series, Project μ SCR-Pro and Endless Curving Slit - all two piece rotors. I decided upon the Project μ because they were roughly the same price (delivered) as the DBA's, and the Endless were just prohibitively (stupidly) expensive. The SCR-Pro are also marketed as now having better crack-resistance and some fancy heat treatment. So I asked a certain Mr Streeter to get the Project μ sent out to me.

Here's a weight comparison:

DBA 4000: ~8 kg
DBA 5000: ~7.5 kg
Project μ SCR-Pro: ~7 kg

And here they are fitted:

Crack Whores

So, a day after MGCC Sandown sprints, I felt this shuddering when I was braking from 60 KPH or more. I then discovered that my front rotors had cracked. The left one has two small cracks and the right rotor has one crack that is more prominent. These are almost 2 years old and have been used and abused for roughly 25,000 KM of road and track days.

Hot brakes & battle scar

The DBA rotors have three coloured stripes on the edge that change colour when they reach a certain temperature.

Temperature (degrees C)/Original colour/New colour:
* 458 / Green / White
* 550 / Orange / Yellow
* 630 / Red / White

Tonight I checked the rotors and found that the red stripe had turned white.

Left & Right:

I also found the source of the clunk sound when I slid off the right hand side of the turn 12. The concrete on the right edge of turn 12 is not level with the grass and it is probably a few centimetres higher than the grass. When the right side of my car slid off the concrete and the right wheels dropped on to the grass, the bottom edge of the part that connects to the lower control arm scraped on the concrete. Luckily it's only superficial damage.

Brake service

A brand new year and planning to jump straight back into track days. So, to prepare for Sandown next week:

1. Bled the front brake fluid and topped up RBF600.
2. Replaced the front brake pads with another set of Project Mu Type HC+.

Comparison of old pad to new. Old pad had worn down to 9.3mm (including the backing plate), which is below mininum thickness of 10mm. New pad is 15.7mm including backing plate. Therefore, the pad's life of 6.4mm was used up from daily driving and 6 track days (4 Winton, 1 Wakefield, 1 Sandown).

New pads fitted. I'll also be trying out some DBA 4000 series rotors (fitted a couple of months ago) for the first time at the track next week.