I've been holding off posting because I wasn't sure it would work, but wanted to throw this out there for people to consider before splashing out on other options. I'm still not sure as I didn't finish everything today, but my new flywheel and clutch are bolted up, and I should finish the last bits of the clutch and transmission replacement tomorrow and see whether it actually disengages, drives, and all that good stuff.
I emailed Matt a while back to see if he would make the few minor changes to his flywheel design to accommodate an Audi B7 RS4 clutch, I even offered to give him a new clutch sent directly to him to aid in mockup and I never heard back. In his defense he's a busy guy, and when I did ultimately decide to go it on my own with his flywheel, he messaged me after the order to offer a switch for a discounted one with a few blemishes. I appreciate that. It is disappointing though as I really do think this is the ultimate BHW clutch setup and with just a few tweaks to his CNC program would have been the definitive choice for B5 TDI swaps all for just a touch more $ than the off the shelf 228mm 1.8T kits.
Pros:
1. it's cheap. $165 at RockAuto. Even with the required modification it still came in well below the cost of any of the Clutchmaster/Spec options and if, god forbid, I ever needed to replace the clutch it'll only cost around half of even a new Stage 1 setup.
2. it's strong and streetable. VAG thought it was strong, reliable, and mild-mannered enough for a 320 ft/lbs luxury sports sedan, and it's been shown to reliably hold north of 400 ft/lbs in various modded B5 S4s.
Cons:
1. You need (or at least I used one) the 5mm block/trans spacer
2. If using the Whitbread flywheel you currently need to modify it; TTV makes a B7 RS4 flywheel that makes it completely bolt up, but it's only 16lbs in the heaviest option.
The mods are pretty straight forward (fingers-crossed it works, but it should, and if not it'll just be a matter of another little bit of machining). The obstacles to overcome are:
1. Machine pockets on the flywheel rim to provide clearance for 3 springs on the pressure plate
2. Solve the 10mm flywheel -> 6mm PP dowel compatibility issue (I chose to drill the PP)
3. Shim the PP 2mm off of the flywheel (I used 2mm precision shims from McMaster)
Overall the total cost was $40 for the pocket machining, and another $40 to rebalance the FW/PP. The B5 S4 guys have pioneered these mods and they have largely chosen to machine down/replace the stock dowels to 6mm citing concerns about introducing PP imbalance, but I chose to drill and there were no issues PP balance either individually or as a rotating unit.