One of the most disappointing things about the MK2 TTRS is the brakes. Despite the RS being equipped with upgraded four piston Brembo calipers and fancy looking rotors from the factory, they overheat fairly easily when pushed to the limit at the track as I found out on my first track day with the car. The good news is everything is super easy to fix, and much cheaper than needing to buy a Big Brake Kit (BBK) like you might need on other cars that are less performance oriented. The Brembo calipers themselves are great (and a common upgrade to many other Audi/VW cars), but the rest of the system has four key weak points:
- The OEM rotors lack sufficient cooling due to the small vents that face the wrong direction on one side
- Lack of adequate cooling (air flow) to the rotors in the first place
- OEM brake fluid is not high enough for track temps, resulting in boiling brake fluid
- Rubber brake lines that lose pedal feel, especially with boiling hot fluid mentioned above
To fix this, I embarked on buying new rotors, stainless steel lines, higher temp fluid, and better air ducts. I’ve yet to test at the track, but based on thorough reading I’m confident this setup will suit my needs. I’ll start this series reviewing the rotors, because they are both the most expensive and perhaps the most impressive mod of the group.
Girodisc Two Piece Rotors
The two main advantages of the Girodisc rotors over stock are that they’re much lighter, and have better cooling. Weight savings is approximately 8lbs less per side in the front, and another 5 lbs or so in the rear. This is unsprung weight, so it has a much more dramatic impact than the mass alone implies. You’re looking at a net decrease of almost thirty pounds of unsprung weight, which is dramatic – far more weight savings that forged wheels will provide, for instance. This weight savings is achieved by using a two piece design, and having the central hat made of aircraft grade aluminum rather than cast iron like the OEM design. When the outer “rings” that are cast iron wear out, you can reuse the central hats and just buy new outer rings, making it a little cheaper to maintain.
Equally important, the cooling is much improved. The face of the rotor has directional slots on the face of the rotor, but more importantly the vents inside of the rotor are bigger and facing the correct direction. These vents between the two faces of the rotor work to pump more air through the side of the rotor and cool both the front and back surfaces more adequately. The OEM rotors have directional cooling vents, but Audi in their infinite wisdom only made them for one side, so on the passenger side the cooling vents are actually facing the wrong way – ouch. Girodisc fixes this issue by making different rotors for Left and Right side of the car, so the cooling vents work on both sides, not just one!
A third, but rather insignificant upgrade are the looks. The rotors do look cooler, and I love the subtle hint of blue on the hubs that give them a little extra pop. The two piece design also has a hint of aftermarket, while not looking too extreme either.
The biggest downside is of course, price. Front rotors are approximately $1,000 a set ($800 to replace the rings when needed), and rears are $850 for the stock size and $900 for the upgraded 330mm size (note: you’ll need the 034 kit to use that). By comparison, new OEM front rotors will set you back around $600-700, so it’s even more expensive than the already expensive OEM options…but for the small upgrade fee, still well worth it as it will prevent cooling, warping, and overheating issues if you track or drive heavy at all.
In hindsight I wish I had spent the extra money to get the larger rear rotors, if anything just to fill out the rear wheels a little better…but overall, I’m very pleased with this upgrade and would definitely recommend to others. It’s expensive, but much cheaper than a BBK and makes a world of a difference.