Tuners thread about Carbon Fiber drive shafts: http://www.dsmtuners.com/forums/showthread.php?t=111223&highlight=aluminum+drive+shaft “The benefits are numerous. First is weight savings. I'm not sure, but I think the stock shafts with the carrier bearings and all weigh at least 80 pounds. This is rotating weight, too. Rotating weight that is robbing your expensive horsepower.
Second is strength. Tortional (twisting) strength is phenominal. And it has an almost perfect elastic memory. That means that it acts like a big shock absorber to the twisting torque and returns to its proper shape. Drag racers that have changed over to aluminum drive shafts will paint a straight line down their drive shafts when they are new so they can tell when they have twisted too much (candy caned) from stress. The carbon fiber shaft won't do this and it will weigh in at about 8-10 pounds!
So what about u-joint angles? Not a problem. Even with the model that replaces all three of the stock shafts the u-joint angle is kept well within limits.
But aren't the carbon fiber tubes fragile to a side impact? They cover the outside of the carbon fiber tube with tough fiberglass. Many Baja racers use the shafts without problems. If you drive over a rock that touches the shaft, that is a different story. While that might bend a metal shaft it will shatter the carbon fiber shaft. A bent metal shaft will rip your drivetrain apart. A shattered carbon fiber shaft will mearly “broom out” and clean your undercaraige while it disintergrates.
Aftermarket Driveshafts: