HKS Kansai carbon driveshaft coming - lighter than current carbon drive shafts

[diss7]

No pricing, still in development (I checked again this morning)

Weight is claimed to be 4.2kg, which is at least 1kg lighter than the current carbon driveshafts available.

Will post when I know more.

[bakerr6]

would love to have a ds this light, but not looking to spend 2k on this type of part atm.

Still, I'm liking where they are going. Thanks for posting this

[chiefshayan]

How do you know it'll be 2k?

[xDanger_208x]

Originally Posted by chiefshayan

How do you know it'll be 2k?

3 letters...
H
K
S

[mav1178]

Originally Posted by xDanger_208x

3 letters...
H
K
S

+ Kansai.

http://www.kansaisv.co.jp/index.html

http://www.kansaisv.co.jp/demo_car/p...odel=democar_1

Everything put on the car is $$$.

-alex

[slava]

Man thats pretty

[AJ PwR]

Carbon prop shafts for S2000 costs about 390000~450000yen so I think price should be around there.

[ciro]

Finally a company uses the correct weave.

[Captain Snooze]

Originally Posted by ciro

Finally a company uses the correct weave.

Why is this the correct weave and by inference the others incorrect weave?

[OICU812]

This is interesting. As I've tried a cf shaft let me explain what I hope this shaft has difference wise. I had a DSS shaft great piece btw. Acceleration and lack of slop was fantastic. No vibration or drive ability issues per say. Only I'm very sensitive "hearing wise" when I'd get to around 70-85mph there would be an air like noise, super hard to explain. Again no vibes etc but to me it was so different it was strange. Now I spoke in great length to some folks that had same concern again only hearing and they had their custom with microballs of styrofoam so like an acoustical filler if you will inside the shaft. I wonder if this shaft comes with any sort of coustic filler???

My other concerns is their glue and what rpm they're balanced to and how their balanced. Good find though gonna sub for updates thanks!!

[ciro]

Originally Posted by Captain Snooze

Why is this the correct weave and by inference the others incorrect weave?

I'm not going to get to much into this but it is basically the angles of the threads and how they braid the threads. The only reason I think this is done better is from reading lots about carbon fiber and how to make it stronger in different directions. Other shafts I have seen use unidirectional weave which is awesome for body panels and random parts made from carbon fiber but not in a shaft that is receiving really only torque and no other stresses.

Sent from my HTCONE using Tapatalk

[chrisl]

Originally Posted by Captain Snooze

Why is this the correct weave and by inference the others incorrect weave?

Carbon fiber is a lot like wood - it's not uniformly strong in all directions. It's much stronger along the grain/weave than it is perpendicular to it. For a shaft loaded in torsion (in other words, pretty much every driveshaft ever made), the maximum loads will be at a 45 degree angle to the shaft. So, for a carbon fiber part (or fiberglass), you want the fibers to be wound at a 45 degree angle for the best strength with the minimum amount of material. Since it can be loaded in either direction (acceleration or engine braking), you want fibers wound around it in both directions, at 45 degrees. You can see this in the shaft above.

For some reason (that I do not understand), many carbon driveshafts instead have the fibers wound very nearly circumferentially, at least at the surface of the driveshaft. This gives very little strength against a twisting load (but it would be great for a pressure vessel, like a composite scuba tank). They must have fibers in some other orientations internally as well, to give them the necessary strength, but even so, the fibers wound circumferentially at the surface are doing almost nothing aside from adding weight - for a driveshaft, you really want all of the fibers at or near 45 degrees (you could maybe make a case for varying the winding angle between perhaps 30 and 60 degrees in the various layers, but even that isn't really necessary).

This also probably explains why they can make it lighter than other CF driveshafts. They also could be using a higher grade carbon - all CF isn't created equal. A standard carbon fiber might have a modulus (stiffness) of around 230GPa and a strength of around 3.5GPa, while a high modulus carbon will have a similar strength and a modulus of around 550-600GPa (so it's 2 or 3 times stiffer, but not a lot stronger). A high strength carbon fiber on the other hand might have a modulus around 300GPa (only a bit stiffer than the basic stuff), but an ultimate strength of around 6GPa or even a bit more (so nearly twice as strong as the basic carbon fiber). Of course, the high stiffness and high strength carbon fibers are a lot more expensive than the ordinary carbon, but using them can significantly improve the strength and stiffness (or reduce the weight for the same strength and stiffness) compared to a component made with basic CF.

[RehabJeff86]

Sick looking CF DS, this will be easily $2k or higher like others said HKS Kansai


Sent from my iPhone using TapatalkfQ

[Turdinator]

Originally Posted by chrisl

Carbon fiber is a lot like wood - it's not uniformly strong in all directions. It's much stronger along the grain/weave than it is perpendicular to it. For a shaft loaded in torsion (in other words, pretty much every driveshaft ever made), the maximum loads will be at a 45 degree angle to the shaft. So, for a carbon fiber part (or fiberglass), you want the fibers to be wound at a 45 degree angle for the best strength with the minimum amount of material. Since it can be loaded in either direction (acceleration or engine braking), you want fibers wound around it in both directions, at 45 degrees. You can see this in the shaft above.

For some reason (that I do not understand), many carbon driveshafts instead have the fibers wound very nearly circumferentially, at least at the surface of the driveshaft. This gives very little strength against a twisting load (but it would be great for a pressure vessel, like a composite scuba tank). They must have fibers in some other orientations internally as well, to give them the necessary strength, but even so, the fibers wound circumferentially at the surface are doing almost nothing aside from adding weight - for a driveshaft, you really want all of the fibers at or near 45 degrees (you could maybe make a case for varying the winding angle between perhaps 30 and 60 degrees in the various layers, but even that isn't really necessary).

This also probably explains why they can make it lighter than other CF driveshafts. They also could be using a higher grade carbon - all CF isn't created equal. A standard carbon fiber might have a modulus (stiffness) of around 230GPa and a strength of around 3.5GPa, while a high modulus carbon will have a similar strength and a modulus of around 550-600GPa (so it's 2 or 3 times stiffer, but not a lot stronger). A high strength carbon fiber on the other hand might have a modulus around 300GPa (only a bit stiffer than the basic stuff), but an ultimate strength of around 6GPa or even a bit more (so nearly twice as strong as the basic carbon fiber). Of course, the high stiffness and high strength carbon fibers are a lot more expensive than the ordinary carbon, but using them can significantly improve the strength and stiffness (or reduce the weight for the same strength and stiffness) compared to a component made with basic CF.

Interesting info

Could the circumferentially wound carbon be a safty measure, to hold the shaft together better at high rpms?