PST Carbon Fiber Drive Shaft Installed

[serialk11r]

Originally Posted by msile

Yeah too bad you have to get under the car to see it.

Who makes it in aluminum?

No one that I'm aware of, but I haven't really been following the aftermarket for this car since I got a different car.

Hopefully someone makes it in aluminum sometime, as that would be a lot more affordable.

[Turdinator]

Originally Posted by serialk11r

After the differential gear ratio reduction is taken into account, the effective moment of inertia decrease is pretty small compared to wheels. Of course, wheels can only be made so light, but their effective "moment radius" is still larger.

I thought it worked the other way since the drive shaft is spinning 4.1 times faster that the wheels therefore reduction in the rotational inertia is 4.1 times more effective?

[serialk11r]

Originally Posted by Turdinator

I thought it worked the other way since the drive shaft is spinning 4.1 times faster that the wheels therefore reduction in the rotational inertia is 4.1 times more effective?

What's the diameter of the driveshaft? What's the diameter of the wheel? See what I'm getting at?

I guess I should've written "the effective moment of inertia decrease is still pretty small compared to that of a reduction of mass at the wheels"

[Turdinator]

Originally Posted by serialk11r

What's the diameter of the driveshaft? What's the diameter of the wheel? See what I'm getting at?

I guess I should've written "the effective moment of inertia decrease is still pretty small compared to that of a reduction of mass at the wheels"

Ahhh, sorry i did misunderstand you. And i absolutely agree with what you are saying. The shaft would have to be ~ 4.5" diameter to make the same difference as lighter wheels. Which is why a light weight flywheel is such a good upgrade, but that has been covered in other threads.

[serialk11r]

Originally Posted by Turdinator

Ahhh, sorry i did misunderstand you. And i absolutely agree with what you are saying. The shaft would have to be ~ 4.5" diameter to make the same difference as lighter wheels. Which is why a light weight flywheel is such a good upgrade, but that has been covered in other threads.

Well of course not all of the wheel's mass is on the outer diameter (whereas much of the driveshaft is) but yea I'd bet that the effective "average radius" is still bigger on the wheels.

[SubieNate]

Originally Posted by serialk11r

That must be pretty awesome. I personally wouldn't spend that money (aluminum makes more sense in this situation imo) but CF is always badass

I have to disagree on the aluminum. Carbon has very very good natural vibrational damping properties and is extremely resistant to fatigue. Additionally, carbon shafts do a great job of smoothing out the powertrain and making it a bit more forgiving. I'd be interested in carbon for this fact alone aside from the weight savings and aluminum will never be able to get anywhere close in that regard.

Nathan

[Spartan65]

I wish they made this for the AT guys and gals.

[ShadowSeraph]

Yes, this is needed for an AT fit.

[serialk11r]

Originally Posted by SubieNate

I have to disagree on the aluminum. Carbon has very very good natural vibrational damping properties and is extremely resistant to fatigue. Additionally, carbon shafts do a great job of smoothing out the powertrain and making it a bit more forgiving. I'd be interested in carbon for this fact alone aside from the weight savings and aluminum will never be able to get anywhere close in that regard.

Nathan

I don't think fatigue is a big issue for a driveshaft since the reverse loads are small and there's not much cycling going on, but I may be wrong. Also while carbon probably damps vibrations better than aluminum, aluminum is still an improvement over steel in that regard, I believe.

[SubieNate]

At least in the cycling world, aluminum frames are the absolute worst when it comes to vibration. Because they require thicker wall tubing and larger diameter tubing to reach the same strength (Aluminum is lower strength than steel obviously, but it is also much less dense so there's still potential weight savings over *most* steels.) they rattle you to death on rough roads.

Steel has a nice "hum" about it and a certain springyness. Carbon is like riding on a cloud, it damps everything out and also has a bit of spring.

Nathan

[F3dzo]

Hell yeah...

[zoomzoomers]

Originally Posted by serialk11r

No one that I'm aware of, but I haven't really been following the aftermarket for this car since I got a different car.

Hopefully someone makes it in aluminum sometime, as that would be a lot more affordable.

What you end up getting serial?

Originally Posted by Spartan65

I wish they made this for the AT guys and gals.

Is the shaft different for AT & MT?

[zoomzoomers]

Cool mod BTW. Maybe I'll work up to doing this, but I don't know if I can justify the cost for it TBH. :happy0180:

[Spartan65]

Originally Posted by zoomzoomers

What you end up getting serial?



Is the shaft different for AT & MT?

According to RSD yes it is, probably in length and spline configuration.