I'd be curious what people think about carbon fiber drive shafts. I've read some posts here, and materials and posts out on the wider internet, and I know there's a variety of opinions on them from wild enthusiasm to meh. I understand the basics:
Lower Weight--about 30 lbs less, in the middle of the car, translating to effectively about 1.9hp equivalent (For an AllTrac: 3200lbs @ 200hp = 16lbs/hp 3170lbs @200hp = 15.85lbs/hp 3200/15.85 = 201.89 or for a GT-Four: 3200lbs @222hp = 14.41lbs/hp and 3170lbs @222hp = 14.28 lbs/hp 3200/14.28 = 224hp). $1400 for a 1.9 or 2 hp gain is not anything to write home about.
Lower Rotational Mass, resulting in (very slightly) more power translated to the wheels. This is not a huge factor as the driveshaft is a small portion of the vehicle's total rotational mass. Plus the drive shaft is a small radius. It seems like lighter tires and wheels would be a better way to get at this--I have a tire/wheel setup that I think is 32.5 lbs each, which is pretty good based on what I've seen.
Better Harmonics, resulting in less noise, vibration, and harshness, and less felt engine shock. This might be the best actual benefit.
Here's a discussion about how not to get too terribly excited about rotational mass and the benefits of a carbon fiber driveshaft:
https://www.w8ji.com/rotating_mass_acceleration.htm
I know there was a group buy organized with ACPT, a long time ago. I'm curious what folks who have a carbon fiber driveshaft think about them.
Lower Weight--about 30 lbs less, in the middle of the car, translating to effectively about 1.9hp equivalent (For an AllTrac: 3200lbs @ 200hp = 16lbs/hp 3170lbs @200hp = 15.85lbs/hp 3200/15.85 = 201.89 or for a GT-Four: 3200lbs @222hp = 14.41lbs/hp and 3170lbs @222hp = 14.28 lbs/hp 3200/14.28 = 224hp). $1400 for a 1.9 or 2 hp gain is not anything to write home about.
Lower Rotational Mass, resulting in (very slightly) more power translated to the wheels. This is not a huge factor as the driveshaft is a small portion of the vehicle's total rotational mass. Plus the drive shaft is a small radius. It seems like lighter tires and wheels would be a better way to get at this--I have a tire/wheel setup that I think is 32.5 lbs each, which is pretty good based on what I've seen.
Better Harmonics, resulting in less noise, vibration, and harshness, and less felt engine shock. This might be the best actual benefit.
Here's a discussion about how not to get too terribly excited about rotational mass and the benefits of a carbon fiber driveshaft:
https://www.w8ji.com/rotating_mass_acceleration.htm
I know there was a group buy organized with ACPT, a long time ago. I'm curious what folks who have a carbon fiber driveshaft think about them.