So here's the story behind my question and this thread.
I think my problem was mostly bad luck, won't start to blame particular parts
But nevertheless... I was always running alu shoes (stock 1.71g Xray or other similar shoes) without problems. Then during the most important race of the year (our national championship race) the clutch just melted up while I was running the first place (new shoes, new springs, new bearings - 45min on them). I still don't know the reason, but all the 3 pins from Xray flywheel came out, bearings were into bits and pieces etc. I might have had the faulty old Xray flywheel, but I had many races on it prior to the race. I decided not to have this problem ever again with a clutch, but the worst thing is that I'm still not sure what the exact reason was...
Then I decided to try the UltimateRacing carbon clutch that most of guys are using here. I was told it doesn't handle wet conditions. Dirt just eats up the carbon shoes. But it was just crazy, worse than I could imagine. The track was watered between two heats and there were some puddles with very little water when my heat started. I got to run few minutes after which the clutch was gone. I know few other guys ran the same clutch. Maybe just a bad luck... again? I could just pulle the clutch bell away from the engine - bearings into pieces, thick shim that holds the bell in the place was gone and there were only 3 springs inside the bell. No traces of the carbon shoes whatsoever
The whole clutch had about 12 minutes on it before dieing, luckily in the last qualy heat. I did put in new set of shoes and springs and raced the final without any problems on dry track, but it was still very annoying thing to experience. Clutch failing the second race in a row. Both times brand new shoes and springs. On my XB8 the same clutch (stock Xray 1.71g alu) has survived 4-5 races without problems.
I'm sure the 28XZ stresses the clutch a lot on a truggy, it has something like 3+hp
I haven't yet had any clutch spring breakage as I tend to service things a lot and used two sets of springs during one alu clutch set lifetime - just in case! It really pisses off if a serviced or brand new part fails on you...
I think I have to go back to proven alu shoes with non-defective flywheel or get some other carbon/teflon/whatever clutch - which.
