New parts or Poly

[edc]

One of the chaps here in UK put the powerflex purple in the rear tuning fork and ended up snapping the arm. I myself have powerflex black ARB bushes and haven't noticed any adverse affects. Can I tell the difference to standard? No because I changed the dampers, springs and top mounts at the same time.

[Robert986]

Originally Posted by edc

One of the chaps here in UK put the powerflex purple in the rear tuning fork and ended up snapping the arm. I myself have powerflex black ARB bushes and haven't noticed any adverse affects. Can I tell the difference to standard? No because I changed the dampers, springs and top mounts at the same time.

Do you mean this one? 911uk.com - Porsche Forum : View topic - Polybushed Tuning Fork Failure

If If I understand it correctly that is a case of wrong application of the bushing, that end of the arm should be flexible to allow for the movement of the suspension. A solid spherical bearing could work, but not a stiff bushing. Or?

I can be totally wrong, if so please let me know!!!

[Robert986]

Originally Posted by Robert986

Do you mean this one? 911uk.com - Porsche Forum : View topic - Polybushed Tuning Fork Failure

If If I understand it correctly that is a case of wrong application of the bushing, that end of the arm should be flexible to allow for the movement of the suspension. A solid spherical bearing could work, but not a stiff bushing. Or?

I can be totally wrong, if so please let me know!!!

Quoting myself.. hmmm what have I become?

Anyway, what I mean is that I believe that it should be the absolute opposite of what this guy at EPS is telling.. Load the suspension.. WFT?? https://www.youtube.com/watch?v=O57sPjCW7YQ

[B6T]

Originally Posted by Robert986

https://www.youtube.com/watch?v=O57sPjCW7YQ

Holy ****************.

- The arm has no "loading capability" because it isn't supposed to. That arm is supposed to move freely in that joint. Not only will adding bushing pre-load change the effective spring rate of the suspension system as the guy mentioned in the video, making it "harder, tougher" whatever that means, the aluminum arm isn't designed to be loaded in torsion... and it also isn't designed to be loaded in bending (you can see the arm bending as he applies force to it). Since those arms are aluminum, they will fatigue and fail very quickly. Again as UK guy found out.

- Surface area limited - irrelevant since the bearing isn't loaded axially. This arm is loaded in compression under vehicle acceleration or tension under braking.

- The loaded surface is actually the width of the white plastic, not just the centre of it.

- EPS may be correct in saying that their product is longer lasting, but without testing data, they can't technically make that claim.


Every. Single. Time. You buy an aftermarket part ask yourself... how many hours did Porsche's engineers spend designing, testing, and optimizing this part? These are professional automotive/mechanical engineers whose life's work is to make those suspension arms, etc. and they put their reputation/job on the line if they send crap out the door since warranty costs can be huge. If it was that simple to improve the part, why wouldn't the engineer have sent the car from the factory like that?

Swapping parts on your car for aftermarket may not always be an improvement.