Not a huge amount extra to report. I've done 7000 miles on them and they are still performing as they were when I first fitted them. They have similar stopping power to stock but with better feel. I know that feel is subjective but, in simple terms, they are less "on/off" than the stock brakes and offer more front axle stability when you are repeatedly braking hard. I have no doubt that this is because they maintain the overall geometry of disc vs pad vs carrier better when stressed, which is exactly what you'd hope for when upgrading from floating calipers.
I would normally have done a couple of big road trips in two years, but it was just the one trip to LM24 2017 in this car, and then I had the pleasure of sharing an M2 and a Cayman GTS (981) for a week in the Pyrenees and Vercors last year - a useful opportunity for comparison! My car has a similar brake feel to the M2 - a bit overservoed but ultimately a big step up from something like a normal 3 series or non-M E85/E86. Apart from the usual rumble of the drilled rotors, there hasn't been a time (in either the Z4M or the M2) I can remember when the brake feel/performance reduced significantly; even when barreling into successive downhill switchbacks.
The Cayman is ahead in almost every way - you can hit the brakes harder and later and the car just gets up on its front paws and then dances out of the corner (even if you get on the power way too early!). It's not just the lightness and balance of the thing either - the brakes are more progressive at the top and more firm at the end of their travel than the BMW brakes (with stock pads and fluids). It's hard to describe, but it almost feels like you're putting a foot out onto the road to stop the car. Loads of feedback and every mm of pedal travel seems to make a difference. I can totally understand why good examples of the GTS are still £60k - a really special car.
Anyways... back to the Zed and the VBTs! They clean up really easily if you have a wheel off. Just a quick wipe all over and they're back to glorious red. Mechanically they are sound - the bolt torque is holding and the HEL lines are like new still. They get a fair amount of comments - from garages and at meets - but not excessively so. I think a lot of people, even those in the know, don't realise that they are aftermarket. They are a bit like CSLs, in that respect.
Minor gripes?
- They are big calipers that require at least a 10mm spacer to clear CSLs. They would be easier to accommodate behind other alloys, e.g. Apex EC-7s, in a way that wouldn't make tyre fitment so critical
- The pads are big and expensive
- Emergency brake assist is still intrusive and a BBK can't really help with that
- The Brembo calipers aren't as common on the secondhand market as much as those from the Cayman/996, although they are slightly more common than the BMW Performance calipers (in my experience - YMMV)
- Very little additional stopping power vs the stock brakes (I'm sure we're massively tyre limited; even with >225mm fronts on)
- Still unproven on track, but I suspect they will be superb with the right pads/fluids
- The bolts are mild steel so the heads rust a little
- They are a bit fiddly to bleed if you are used to single pot calipers
- No matching rear. A Brembo 31/33 is the hypothetical 4-pot that will match our master cylinder perfectly
A repost of some of the pics that got dropped off the thread:
R60BBA - cheers for asking. I've got a South Wales weekender coming up so I might have some more to report back on after that.
