I haven't installed my OBX yet. Got it ripped apart and am going to wire wheel the ends of the helix gears and splines to de-burr them a bit (tho honestly the quality of mine is much much higher than many pics I've seen online).
I bought one of those Belleville washer + new bolt kits ... but the OE Bellevilles were installed correctly, the bolts were all torqued properly, and none of the threads were damaged. Appears they are stepping things up.
I had (dad drives it now) a Quaife brand helical in my Saturn SL2 for 70,000 miles (in addition to running an open diff for 25k miles and a Phantom Grip for 25k miles). The helical was downright magical. You absolutely never noticed it was there. With the one wheel on ice one wheel on pavement scenario, it would spin the wheel on ice, but you would still accelerate. The transition of torque from one wheel to the other was very smooth resulting in no jerkiness or torque steer whatsoever. After a while I just got used to having really really good traction in a FWD car and actually started believing that was a decent drivetrain again. Then I'd drive a rental car or a friend's car and wonder how on earth anyone could get anywhere in such a rig (with an open diff). I had to replace the input shaft seal 65,000 miles into the life of the Quaife, so I got a chance to see how it was holding up. Zero wear, no metal in the trans fluid (or on the magnet). Lot of those miles were with a high comp 11.5:1 CR quad throttle body engine that was making 155 HP to the wheels and spinning to 7500 RPM putting power through a 4 puck ceramic solid hub clutch.
It would be a perfect match to a high HP engine in a light car (even with 4wd/awd). In a PT4wd trans, it'd be even better as you could pop the thing into 2wd for mileage and have enough traction to leave it there in light snow/dirt roads. I'd also wager that increased front axle traction would significantly reduce stress on the rear driveline ... to say nothing of embarrassing cars like WRXs with their visco rear, visco center, and open front.
Edited by Tycho, 05 January 2011 - 03:40 PM.