So, time for a complete write-up.
I have driven some some thousands of kilometers with the new front brakes and I am very content with them, let's put that up first. As I wrote previously, the hearts are still to come, but it works already pretty well with the E39 brakes. Thing that I learned is that it is tight. So tight that I would not recommend the E34 brakes, though they are just 6mm larger in diameter. I needed to replace the balancing weights in the wheel. That tight. Somewhere in the future I will test the Alpina wheels as well, but with my 15" BBS Mahle it works out.
First the balance:
I bought the callipers and Ultralight discs at DansHouseOfSpeed through eBay, so I needed to pay the Dutch import costs. Proportioning valve I bought in the Netherlands at Hendriks Motorsports and is mostly a must have for all E21's that are driven a bit more vividly since you gain 15-20% more braking power at the rear, regardless whether you have discs or drums. The brake hoses I have ordered custom made at Remkaflex.
I started this all because I did not believe that the Volvo 4-pot option was anything of an upgrade and the other described option of the Wilwood Powerlite Radial Mount actually offers a smaller pad area compared to stock E21. I did not want to pay the amount of money asked by the different shops and hoped to save some money. Did I? Yeah, but in hours researching and actually still having the heavy E39 discs... I don't know. I actually forgot it all already since it brakes wonderfully.
Some more numbers:
BMW E21 stock: 32.8cm2 pad area / 3.8kg calliper weight / 255mm max disc D
Wilwood Powerlite: 32.25cm2 pad area / 1.27kg calliper weight / 279mm max disc D
Forged Narrow Dynalite: 41cm2 pad area / 1.86kg calliper weight / 323mm max disc D
34111163128 E21 solid: 255mm D / 4.9kg
34111163125 E21 vented: 255mm / 5.1kg
34111163013 E39 vented: 296mm / 7.4kg
160-0471 Wilwood Ultralite 32 vane rotor: 298mm / 3.7kg
So I went from (4.9+3.8 ) 8.7kg to (7.4 + 1.86) 9.3kg per side. Plus bracket. Imagine that the hearts can be 1kg each, combined with the Ultralights, I could save some kg's of unsprung weight.
I chose the Forged Narrow Dynalite since I wanted a tangential mount since the brackets for these are far less complex, just 2D. I chose 296mm since I wanted the maximum diameter disc.
Wilwood Forged Narrow Dynalite 120-11575
Wilwood Forged Superlite Internal 120-11128
Wilwood Proportioning valve 260-12627
BMW E39 528i Ventilated 34111163013
Ferodo DS2500 FRP504H or FRP502H and redrill the holes like I did to match the aluminium tube
Thickness is 6.5mm.
Brake hoses are really nice ones. This is the drawing I send:
This is what I received:
Note that the Wilwoods will be delivered with some Imperial thread while BMW used M10 fine thread.
From the calipers I removed the plastic tube and replaced it with an aluminium tube. The weird bolt is replaced with M6x120:
The two mounting holes in the calliper for the bolts I drilled to 12.5 to clear an M12.
The discs come with 14.5mm holes, there I tapped M16 and fitted M16 bolts, which I glued in place with JB-Weld. Later I cut them and ground it all flat again.
And redrilled a 4x100 hole pattern:
I completely removed the dust shield:
And fitted nicely:
And some animation:
So... Where I got my pads fading with ease with the solid E21 discs at about the same points where the heavier 323i's get problems as well, I have not felt anything with this combination. At one point I have braked like a complete mental, really like I never have done. From 160km/h to standstill and over and over again. Yes, they get hot, yes there is smoke, but there is no pad fading. I feel absolute confident in entering the Alps with these. On top of that, a lot more feeling to the pedal. Where I was used to blocking brakes at high speeds, I can really control the amount of breaking and kind of feel where the tipping point is. The only downside is, which I mentioned earlier as well, is that when everything is cold, the Ferodo's don't really perform. At braking from for instance 140 back to 80, nothing happens really until there is temperature at 120 and then it starts.
When you don't think that the Dynalite is enough, you can go with the Superlite Internal as well. Outside radius of these is the same, as well as the mounting points, so you can use the same brackets. They weigh 2.4kg and have a pad area of 52.9cm2.