Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB - PST vs DSS carbon driveshafts, anyone compare?

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PST vs DSS carbon driveshafts, anyone compare?

Curious as these are both out. Both have some interesting differences on how they're made and so fourth. But there is no clear winner from what I can see as just a guy researching. Having never seen or used either of their products it's bit tough to know. PST shafts are everywhere while DSS take a few weeks to make, both are within 150 bones of each other cost wise....

Anyone that has this car have chance to compare these cf shafts to each other?

Reason considering cf over aluminum is the noise reduction of CF which makes seen to me.

Thanks if you can provide info on either or have some experience with both!:w00t:

Whilst I appreciate the question being asked I doubt there will be too many people who have bought both to do a side by side comparison. I have read elsewhere of issues that have plagued the odd shaft by both PST and DSS.

Love my DSS cf. If you get me a PST I'll compare them for you.

Sincerely I figured no one has but had to ask cause well... Some people here spend a ton and would! Lol maybe just too early for the platform for such questions I suppose. :)

Quote:

Originally Posted by OICU812 (Post 1144821)

Sincerely I figured no one has but had to ask cause well... Some people here spend a ton and would! Lol maybe just too early for the platform for such questions I suppose. :)

Ask me about any of other thousands of dollars of modifications I've done!

CFDS or even an aluminum DS is on the list for "one day" though.

Quote:

Originally Posted by OrbitalEllipses (Post 1144862)

Ask me about any of other thousands of dollars of modifications I've done!

CFDS or even an aluminum DS is on the list for "one day" though.

Lol. Thanks for keeping me in check as always Orbital! :)

I want to see weights, materials and close up of flanges and brands of u joint etc before I buy

PST has better CF weaving

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Quote:

Originally Posted by RehabJeff86 (Post 1563999)

PST has better CF weaving

Why do you say that? I'm genuinely curious how you came to that conclusion. Not at all trying to debate what you say there because I have no opinion or evidence of the contrary, but I'd like to see some evidence or whatever your source of such information is because I would like to know the answer about that myself. No offense but the word of some random person on the internet isn't exactly a reliable enough source of information for me to make my decision on.

Quote:

Originally Posted by RehabJeff86 (Post 1563999)

PST has better CF weaving

Quote:

Originally Posted by RallySport Direct (Post 1418102)

Just to start off, this is NOT to start an argument and more to help people understand about carbon fiber and how it is used.

As chrisl stated carbon fiber strands are strong in tension, and weak in every other possible aspect(think of a rope). So to get the most strength from the fibers you want the fibers to be in tension. In any other direction all the loads are being taken up by the Resins that are used to hold the carbon together.

The interaction of the resin, the type of resin, and amount of resin has more to do with how a carbon fiber acts when loaded then just the carbon itself. Resin makes up between 35-50% of the material, and can have not only your basic components but also things like nano-carbon tunes and fillers to make it stronger or flexible. The better the resin for the application the more load the entire matrix(term used to describer carbon and resin sample) can hold in all directions but ultimately it will be the strongest in the direction that puts load on carbon in tension.

Carbon fiber is made in layers, a single layer is thin (1/4" thick piece of carbon fiber is anywhere between 75-150 layers) and each layer can be oriented in a different direction to give you the desired results. The worst way to use carbon fiber is to make it quasi-isotropic (making it the same in all directions), so manufactures will mix layers and put material in different directions depending on what properties they want from the material.

For this application the ideal placement of fiber direction is along the direction of load, which is around the shaft in the perpendicular direction. However due to the weak bond between the resin and fibers the shaft would simply sheer if all fibers were in that direction. Then if you put all fibers in the parallel direction there would be no sheer issues but you have load issues were the shaft is not able to take high loads with out bending. So it comes down to a fine balance of each different aspect.

Last but not least, unless you are the manufacture you do not know what the manufacture has done to the carbon, what carbon they use, what resin they use, and in which direction they have placed the carbon elements. Carbon fiber is typically 8-20 layers deep and each layer plays a critical part in how much load the matrix can take and in what direction. The automotive industry is driven by aesthetics, so everyone makes the outside of parts look shiny and pretty. But with carbon fiber its on the INSIDE that counts. And given that people buy majority of parts on how they look on the outside, many manufactures go out of their way to make outsides of parts look more impressive then 98% of the rest of the product. No carbon manufacture will simply come out and tell you what resin and carbon they use, what manufacturing technique, what carbon lay up, and the curing temperatures/pressure as that is the "secret sauce".

So the moral of the story is simple, you simply cant look at a true carbon fiber part and say if its "good" or "bad" with out running tests on it or getting the manufacture to tell you the recipe to their "sauce" on how they made it and so forth. Its like looking at a cut of raw steak and guessing the age of the cow and where the cow came from with out knowing all the details.

My bold.
.

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Originally Posted by Captain Snooze (Post 1565189)

My bold.

Yes, exactly. This is where I'm coming from too, and thus why I'd like some EMPIRICAL evidence of said claims. Without testing of some sort (tearing both apart and examining the layup of the fibers, pushing both to the point of failure, measuring twist/bend/etc under load, spinning both and checking for any funny resonances, etc) any claims of one being better than the other is based purely on the grounds of cosmetics (which I don't care about).

Quote:

Originally Posted by mitosis (Post 1565349)

Without testing of some sort (tearing both apart and examining the layup of the fibers, pushing both to the point of failure, measuring twist/bend/etc under load, spinning both and checking for any funny resonances, etc) any claims of one being better than the other is based purely on the grounds of opinion,second hand stories and/or rumour.

Fixed.

In torsion stress is actually highest in a helical pattern running 45* to the shaft if I recall correctly.

Additionally, you can't really compare just by the outer wrap. Some companies do a simple hoop (perpendicular to the shaft) layer just to protect from impacts/debris. It's the easiest and quickest way to lay down a continuous layer of fiber.

All fiber perpendicular would be bad. The shaft would have zero strength either longitudinally or honestly, even in tension. Doing that would put all of the load into the matrix, which would shear apart at a very low level of strength. Even in a situation where 90% of the load is in a certain direction, you need some fiber running at an angle to that (usually 45*) to both hold the main load bearing fibers in place and make sure the load is shared as equally as possible by all of the fiber present.

Things like fishing rods (which are likely pulltruded which is another ballgame) are one of the few applications where all or nearly all fiber is placed in one orientation. Even a driveshaft has a minimum of two (+-45*).

Cheers
Nathan

Unfortunately theres no formal testing done to back my statement, its solely my opinion when i was deciding between PST vs DSS, i went for PST cuz it has 45 degree angled CF weaving which i think its better and stronger. Does DSS hv 45 degree weaving layered under? That i dunno. Otherwise i think both DS perform equally well

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Quote:

Originally Posted by RehabJeff86 (Post 1565677)

I went for PST cuz it has 45 degree angled CF weaving which I think is better and stronger.

Cool, thanks for getting back to us :w00t:

Where did you find out about the 45 degree weave? I can't find anything on the PST website about that. I agree that such a thing sounds like a good idea.

Weave and lay up are very different
Layup matters much more in cf construction

Where are each shafts made?
By whom? By hand?

What is the qa process and qc on each product!

Where are stress test data?
I got money but need answers before I go plopping Down 1000 for a shaft

Still no clue which one is better

Quote:

Originally Posted by kiichiro (Post 1566065)

Still no clue which one is better

Perhaps,in the grand scheme of carbon fibre drive shafts, they are both equally good.

I think this shaft looks the best. That is,purely in an aesthetic non-functional way. Would be even better if the weave had custom colour options. "Yeah bro,that gold and green weaves matches my baseball cap, :party0030: "

Wasn't there a difference how each shaft is bonded to the yoke? They simply can't be constructed the same, or identical

Can each vendor chime in with cutaways or something?

That Pic looks like it's carbon bonded to aluminum is that the same on both shafts ?

I have a pst driveshaft and can confirm that the weave is not perpendicular. The outer layer is (for the final coating and protection) but the inner weave is done at approximately 45' (couldn't measure). You can subtly see the inner weaves imprint with the eye but not with a camera.

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Originally Posted by Deathreaper (Post 1566446)

Have you taken your car upwards of 140km/hr -- 85+ mph and notice any vibes or strange sounds/coustics at all??

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Originally Posted by mitosis (Post 1566018)

Cool, thanks for getting back to us :w00t:

Where did you find out about the 45 degree weave? I can't find anything on the PST website about that. I agree that such a thing sounds like a good idea.

Jason @ DSG Performance told me and here is a pic when i got it, same weaving as the HKS Kansai CF DS which will be available soon, list price is 120,000 Yen like 1200 USD

Attachment 68823

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Quote:

Originally Posted by RehabJeff86 (Post 1566542)

That looks pretty good. Any idea on how the PST shaft is balanced? I know DSS has the small weight tabs visible on outside but I've never had clarification on how pst shafts are in fact balanced...

I sent u pm btw.
:)

Quote:

Originally Posted by OICU812 (Post 1568029)

Cha Ching

Any updates with data between these two shafts?

I have a DSS shaft. No complaints.