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How much Torque are the OEM shafts designed for? The Lindsey Racing/Driveshaft Shop ones are rated for 3450ft lbs of torque (Aluminum), and 4500ft lbs of torque (Carbon Fiber). I doubt your engine will ever come near those capabilities...
I want you to take a look at these two videos and explain to me what's going on. It's an incredibly important engineering principle that is tough to model when you have rotating objects at high speeds, torque, and vibrations involved in one place. When you can adequately explain this this, you'll have your answer about on why a simple intended usage strength means very little here. Or in case of the bridge, static objects with long lengths and small diameters. I simply don't have it in me to explain this start to finish. My guess is that you won't adequately cover it, because that would arrive at a conclusion that refutes most of what you've said here.
Wrinkled - you're firm on the idea that the articulated shaft is there by design, to thwart resonance? The guibos and those little center support bearings taking the brunt of the force?
I don't know where I stand, but mine feels soft - and my center bearing and guibo are fine. I think I'd like the more firm-ish feeling of something solid, but not sure at direct or indirect cost.
Hope to see some reports back after a few months from testers.
I have been running the Lindsey Racing one piece aluminum shaft for six months and about 6000 miles. All is good.
Wrinkled what new wiper arms and blades?? Mine suck.
Originally Posted by seankrider
Careful, there may not be room for hard facts or empirical evidence in this thread...
I appreciate real feedback and facts here. We need actual data points and feedback to know if an upgrade is worth while.
So here is the score card so far.
We have 1 user with 6,000 miles and 6 mo of use.
Compared to the thousands of Cayenne users that have an average of 80-120K of use over -8-10 years.
Nope - I'm not firm on anything except the fact that driveshafts aren't as simple as 1-piece > 2-piece. Or that the only consideration is the torque rating. It's far more complicated than that. That's my only point.
If you have specific goals and account for all the variables, yes a 1-piece might make sense for you. But, if you're looking to fix what you think is a design flaw without understanding why it's designed that way, well you can see how this is a fools errand. Our driveline works synergistically, but according to Villian, it's very compartmentalized.
Old school motorcycles used to wheelie nearly everywhere. Modern superbikes can put the power down and translate it into forward motion, not rotation.
Totally different concept. The reason modern motorcycles don't wheelie everywhere is as simple as electronic traction control. They're making so much power now that we call wheelies with them "Power Ups" or "Pow Pow's", because all you do is twist the throttle (With traction control turned off). You used to actually have to have some skill and clutch feel to do a wheelie..in the old days (IE: Up until 2002).
Originally Posted by Cole
I don't see any TransAms wining the Trans-syberia rally either! ]
I don't see any Transsyberia's tearing up and breaking the OEM Cayenne Driveshafts either...wait...OOOPS! JK!
Compared to the thousands of Cayenne users that have an average of 80-120K of use over -8-10 years.
Really? Where'd you pull that one out of? I know many people with shafts that didn't make it past 60k miles, and plenty more who have replaced them in the Cayenne's more times than they could count. If you want to use statistics then at least use real ones..or gather them yourself. The average mileage that everyone has been getting out of the cardan's is far less than 80k on the Cayenne's. It's so commonplace I'd say 40-60k is the average.
Really? Where'd you pull that one out of? I know many people with shafts that didn't make it past 60k miles, and plenty more who have replaced them in the Cayenne's more times than they could count. If you want to use statistics then at least use real ones..or gather them yourself. The average mileage that everyone has been getting out of the cardan's is far less than 80k on the Cayenne's. It's so commonplace I'd say 40-60k is the average.
What in the fvck are you talking about? I just took 5 minutes and totaled up the cardan shaft failures from this poll. 27 data points and I used current mileage if they hadn't failed yet. Since most of the current mileage numbers were less than the average, the actual average is likely higher. If your simple mind needs to re-read that sentence to comprehend it, please do. I know math and reality aren't your strong points. 27 people with actual data that from this forum - you're welcome to check yourself. And, would you guess what the mileage is?! 90.8k miles is the average failure. And yes, I converted KM to Mi's as to not skew the data, and used 2 60k data points for mudman. I suspect if I pulled out some outliers, it would be closer to 80K miles.
So - please. Villian. Enlighten me with something you can prove online for driveshaft failures. Not your imaginary friends that have all these cayennes with cardan shafts failing at 50K. Maybe you told them to drive around with the diff locked? Look at any cardan shaft poll from rennlist or 6-speed - you'll end up with the same numbers.
What in the fvck are you talking about? I just took 5 minutes and totaled up the cardan shaft failures from this poll. 27 data points and I used current mileage if they hadn't failed yet. Since most of the current mileage numbers were less than the average, the actual average is likely higher. If your simple mind needs to re-read that sentence to comprehend it, please do. I know math and reality aren't your strong points. 27 people with actual data that from this forum - you're welcome to check yourself. And, would you guess what the mileage is?! 90.8k miles is the average failure. And yes, I converted KM to Mi's as to not skew the data, and used 2 60k data points for mudman. I suspect if I pulled out some outliers, it would be closer to 80K miles.
So - please. Villian. Enlighten me with something you can prove online for driveshaft failures. Not your imaginary friends that have all these cayennes with cardan shafts failing at 50K. Maybe you told them to drive around with the diff locked? Look at any cardan shaft poll from rennlist or 6-speed - you'll end up with the same numbers.
Surprise, surprise. You actually substantiated a post for once. I was not aware of that thread. So let's say that the average failure is indeed around 80-90k miles for the first one like you've said. Is that acceptable? Do you really think that a properly balanced, single-piece shaft that's stronger than the OEM one wouldn't last longer? Why not? I'm all ears.
I want you to take a look at these two videos and explain to me what's going on. It's an incredibly important engineering principle that is tough to model when you have rotating objects at high speeds, torque, and vibrations involved in one place. When you can adequately explain this this, you'll have your answer about on why a simple intended usage strength means very little here. Or in case of the bridge, static objects with long lengths and small diameters. I simply don't have it in me to explain this start to finish. My guess is that you won't adequately cover it, because that would arrive at a conclusion that refutes most of what you've said here.
You can also observe this effect inside your Cayenne if you playback a 33hz note at a decent volume with a woman inside (I bet you didn't know that..). So yes, I'm not a retard and I fully understand the concept of Resonance. I also fail to see how this relates to a perfectly balanced drive shaft. These 1 piece shafts are tested for any resonances between a range of 0 and 9500 RPMs. So while natural resonances can still exist in the drive shaft outside of that range, they will never exist within that range or during driving conditions in any Cayenne. That is, unless you can manage to make your drive shaft spin at a rate faster than 9500 RPM's...in which case I'd love to know how you managed that!
Resonance cannot exist without a cause. The helo and Tacoma Narrows bridge both had simple causes. A perfectly balanced drive shaft in a Cayenne has no cause to oscillate (For lack of a better term). The biggest reason I see for Porsche not producing these as original equipment is because it would add to the production cost and cut their margins. A 1 piece drive shaft demands higher quality, and with that comes added cost. That's not even counting the additional R&D, and material cost.
"really? Where'd you pull that one out of? I know many people with shafts that didn't make it past 60k miles, and plenty more who have replaced them in the Cayenne's more times than they could count. If you want to use statistics then at least use real ones..or gather them yourself. The average mileage that everyone has been getting out of the cardan's is far less than 80k on the Cayenne's. It's so commonplace I'd say 40-60k is the average."
oh no he di-ant
the % of owners who post to online forums is < 5% mostly disgruntled for one reason or another
Dealer stats do NOT support your FACT
When you buy your new one, develop a relationship with the service advisor , its amazing what FACTS you can pick up
In reality the Driveshaft (Cardan) failures, making no design arguments), are probably a factor or age, power? (S compared to Turbo S), and mileage/use. Seems like earlier higher mileage owners made it to the higher mileages before their driveshafts failed, us lower mileage (per year, no daily driving) users seemed to have failures with lower mileage but after longer life (timewise). We all know any rubber on a vehicle ages, whether due to weather, ozone, or just time (oxidation, heat cycles).
I only have 72K on my CTTS and I'm trying to decide if I'll keep it another 4 years or more. A Cardan every 65K isn't too bad but we all like to see improvements and I for one would like to keep hearing feedback on the lindsey (The Driveshaft Shop) shaft. I probably never feel the extra power of the weight savings (rotating mass weight savings), although it will be saved in both weight and diameter in a Lindsey shaft. I the feedback on the Lindsey shaft is great that may very well be my next shaft. Only time & mileage will tell but both Lindsey Racing and The Driveshaft Shop have great reputations.
12-08-2014, 08:39 PM
