Velox Motorsports Carbon Driveshaft Thread

[churchx]

Meanwhile i hope Eric doesn't take those joint existence mentions as possible extra crash safety point as any bashing of product. Even if it is so, he has no financial/technical means to do crash testing himself, and his CF shaft product is no less safer then that of other one-piece alternatives on market. If many buyers of those decide for themselves that "it's safe enough for them"/"not a serious issue to care about", things are at very least not worse in any way with his product. So if anyone wishes to start witchhunt on of single-peace shafts unsafety, it would be very wrong to single out just one most recently made alternative on market and bash it. Personally i won't buy it, but not because of some safety concerns, but rather due high price, having other mods of higher priority in purchase & install queue prior that, but see it as good product for those that want to do complete as possible car lightening or for those that want more reliable shaft that is stronger for transfering more torque (eg. for forced-induction-ed twins). After all, if people start looking for stronger gearboxes, upgraded gear sets .. shaft might be failure point too.

[new2subaru]

Some info

5.5 SAFETY
-
Safety is greatly enhanced with composite
shafts. Composites absorb energy upon impact. They can be
designed to, and will normally, break apart during an accident
rather than entering the passenger compartment catapulting the
vehicle, or whipping a broken end through a tank or valuable cargo.


2 shows a broken composite driveshaft. Note
the broken pieces rather than the bent and twisted club that is
usually left with metal. Impact with hard objects like frame
rails will cause a composite shaft to disintegrate and quickly
dissipate energy. A failure in a bond joint would simply result
in a loss of power. The shaft would probably stay in place
with the loose end spinning inside of it.


Above 128 mph the driveshaft gets into a bending
and vibration frequency that would eventually tear it apart.”
They continue that,to eliminate this problem most high
speed European cars usually have a two piece shaft connected through a center bearing.” Carbon fiber driveshafts can alleviate this problem


http://www.acpt.com/resources/documents/sae_1966.pdf

[churchx]

Thanks. That is fine piece of info, that fends off crash-safety concerns, at least for me. So if someone ever wants to think that uni-piece aftermarket shafts are less crash-safe, that should be attributed only to metallic (IIRC aluminium) ones at most.

[new2subaru]

Originally Posted by churchx

Thanks. That is fine piece of info, that fends off crash-safety concerns, at least for me. So if someone ever wants to think that uni-piece aftermarket shafts are less crash-safe, that should be attributed only to metallic (IIRC aluminium) ones at most.

You're welcome, Church. Science & Engineering...

[wparsons]

Originally Posted by JDM4E

Like this:




In longitudinal direction, in case of o tube or similar - now allow me to simplify - almost everything is relatively strong. Even a piece of paper rolled into a tube is quite strong like that.

That drawing assumes that the joint attachment to the body is the weakest link. The joint isn't floating or free to bend without the bearing block separating from the body.

As for the tube, that assumes the material is strong in that direction. Carbon driveshafts have the fibers oriented to be strong with rotational forces at the sacrifice of longitudinal forces since they'll never see any force like that in a useful scenario.

[Falcon]

To which RPM will you test/balance your CF-Driveshaft?

If i do not have miscalculated, it will spin with nearly 9250RPM when i would be going 155mph.

Vibrations are a real concern for me.

[Tokay444]

Originally Posted by Falcon

To which RPM will you test/balance your CF-Driveshaft?

If i do not have miscalculated, it will spin with nearly 9250RPM when i would be going 155mph.

Vibrations are a real concern for me.

Touched on in the OP.

For Velox, are there any distinct advantages of this carbon shaft over the existing solutions on the market, aside from your published testing info that is?

[VerusEric]

Originally Posted by Falcon

To which RPM will you test/balance your CF-Driveshaft?

If i do not have miscalculated, it will spin with nearly 9250RPM when i would be going 155mph.

Vibrations are a real concern for me.

From the manufacturer, they are guaranteed to 9,000 RPM. However, they say users should have no issues up to 11,000 RPM, but they can't guarantee it.

Originally Posted by Tokay444

Touched on in the OP.

For Velox, are there any distinct advantages of this carbon shaft over the existing solutions on the market, aside from your published testing info that is?

The major takeaways:

-Doesn't interfere with short shifters
-Extremely high-end materials and manufacturing techniques
-Frequency balanced, which results in a superior balanced shaft
-I believe these may be the lightest on the market
-7075 cold forged ends vs 6061-T6 which is more standard

Thanks,
Eric

[Falcon]

Thank you very much for the Information.

[cammyT]

So the cf ds is 55% lighter than OEM but what is the diameter compared to OEM? Seems higher wich may in fact negate the weight savings.

Sent from my SM-G920P using Tapatalk

[will300]

On the whole crash safety issue, this video show's you what happens with the stock driveshaft during a head on collision, watch from 6:52.

[ame="https://www.youtube.com/watch?v=6LQKqs_IvgQ"]2014 Scion FR-S / Subaru BRZ / Toyota GT86 | Frontal Crash Test | CrashNet1 - YouTube[/ame]

[FirstWinter]

Any feedback on fitment with shifters like the CAE Ultra shifter or the IRP shifter? If fitment is okay with short shifters like the Kartboy it should be okay with these shifters as well right?

[VerusEric]

Originally Posted by cammyT

So the cf ds is 55% lighter than OEM but what is the diameter compared to OEM? Seems higher wich may in fact negate the weight savings.

Sent from my SM-G920P using Tapatalk

I did the estimated moment of inertia for both stock and the carbon fiber one earlier on in the testing. I estimated that the carbon fiber driveshaft was slightly less than OEM. I can try to dig this up again if you'd like. Realistically, I think the reduced MOI is one of the lesser qualities of this driveshaft, but that is my opinion.

Originally Posted by FirstWinter

Any feedback on fitment with shifters like the CAE Ultra shifter or the IRP shifter? If fitment is okay with short shifters like the Kartboy it should be okay with these shifters as well right?

Post #5 has the answer: http://www.ft86club.com/forums/showp...42&postcount=5

Thanks,
Eric

[twag4]

Ill be ordering soon!