Okay, let's see if I can get all of this straight enough to make sense. I just got off the phone with Ron Main. He got my email a few days ago asking about the Speed Demon's rear end - but was with the car at SEMA and didn't get to call me 'til now.
The car now is set with a Ferguson-built Champ-style rear end. Billet, with a pair of front bearings, a 1.400" input shaft, and zero-degree pinion angle. These mods should, he and crew feel, get them the life they need for the rear end. The pinion angle was part of the problem, and the shaft wiggled before the new (extra) bearing set was put in.
As for the rear breaking -- they've programmed the MoTeCs to take out some timing and boost as the motor approaches shift rpm.
They also use the MoTeC to control (as you'd expect) the horsepower in each gear to help keep the drive wheels from breaking loose. He reminded me that because the car has the extra-stable design it does -- that there's no waggle when the rear breaks loose -- the driver doesn't know that he's sitting on spinning wheels and therefore doesn't know he should try to pedal it. The result -- very little wheelspin.
Oh, yeah -- the Duttweiler V-8 makes about 2200 horsepower at full boost (31#). Not 3,000 or whatever else you've heard. And in first the engine is limited to about 600, by the way, each gear getting more and more.
I expect I'll be getting some photos soon -- of the rear tires after a run where the wheelspin was NOT controlled.
So saith Ron Main.