Is polybronze the way to go?

[Thrlls]

I think there's too much thought being put into this.

If you're keeping your car on the street, get rubber!
If you're tracking your car, get PB!
If you want a nice smooth quiet ride, get a Lexus and sell your SPORTS CAR!

Remember, the 911 is a Sports car with emphasis on SPORT!
Which will equate to expected NVH.

[jonbot]

Originally Posted by Thrlls

I think there's too much thought being put into this.

If you're keeping your car on the street, get rubber!
If you're tracking your car, get PB!
If you want a nice smooth quiet ride, get a Lexus and sell your SPORTS CAR!

Remember, the 911 is a Sports car with emphasis on SPORT!
Which will equate to expected NVH.

Woody, I considered writing you this in a PM, but since you've publicly voiced your opinion, I don't see why I shouldn't either.

Frankly, I questioned the tone behind a couple of your posts in my thread. It's obvious you think my concern about the ride quality, or the maintenance schedule, is humorous. That's fine you think that, but other posts on here have revealed that I'm not alone in my concern. Overall, this may not be as important of a decision to you as it is to me, but you should still respect my attempt at doing research before spending money.

I'm not angry with you or anything, and I enjoyed meeting you at the Bruce Anderson maintenance class, my first impression was that you are a nice guy. Therefore, I'm trying to take your input as you only meaning well, but it's hard to when I feel that my attempt at doing research has become your joke.



Jon

[87 clubsport]

Hi gentleman, just want to tell you about pb bushing, it is very smooth ride in street, if you want rubber one you have to go for OE porsche pls note that porsche only supply it with whole a arm and whole spring plate, or you can buy after market this means you may have harsh ride, so damper and sway bars actually affect more harsh ride not pb bushing, thanks

[island911]

Originally Posted by dd74

.. and yes, I see no reason why they shouldn't last longer than OE rubber. Why wouldn't a metal last longer than a rubber ...

LOL, 30 years, and a Billion or so cycles to the rubber solution

vs ....

Originally Posted by RWebb

"global warming; consensus, based on skewed data"

- Indeed, this sort of sub-scientific gibberish simply diminishes any persuasive ability Island might have had otherwise. Even with hundreds of the top planetary scientists ...... anyway, welcome to the Flat-Earth Society, Island. Your opinions not only lack expertise; they lack even common-sense.

http://epw.senate.gov/public/index.cfm?FuseAction=Minority.Blogs&ContentRecord_id=f80a6386-802a-23ad-40c8-3c63dc2d02cb (U.S. Senate Report: Over 400 Prominent Scientists Disputed Man-Made Global Warming Claims in 2007
)

try to keep up Randy. Even Chuck is suspect of that Global BS.

[RWebb]

I don't get my science from the Republican blogs. More garbage, Island.

How deep are you gong to dig yourself in?

BTW, can you produce any peer-reviewed scientific papers indicating that global warming is not happening??

[dd74]

Originally Posted by island911

LOL, 30 years, and a Billion or so cycles to the rubber solution

vs ....

OK, Island - you have my attention. Explain "where," "how," "what," and "why." Plus why rubber would be better in this instance, even as it deteriorates. I promise to read devoid of bias. Oh, and please explain in layman's terms.

[Gordo2]

Sounds like a technical advertisement for Trojan...

Originally Posted by island911

FWIW, oiled rubber bushings are used in various applications. (where the interface between the rubber bush and the center pivot is lubed.) It has good effect/action, but Porsche landed on a solution where most of the deflections (small ones)are simply taken up by the rubber flexing in shear. This works out well as the flexible material can accommodate most all the needed swing. For large deflections the OE bushings are designed to slide. They then slide without the extra smoothness of a greased rubber bushing, but is still plenty smart; as for the really big deflections you don't care if a small bit of energy is taken to drag the bushing. And you also needn't worry about a failure mode of torn rubber.

Oh, be for warned, Chuck has claimed, for years, that the OE bushings are built/designed in a way that does not allow them to slip. Tho' since he is now replacing them, I guess that he must have finally listened to SOMETHING I've said. ...or maybe he's gluing them in place, just to be "right'.

[dd74]

Originally Posted by dd74

OK, Island - you have my attention. Explain "where," "how," "what," and "why." Plus why rubber would be better in this instance, even as it deteriorates. I promise to read devoid of bias. Oh, and please explain in layman's terms.

And the crickets say, "Chirp-chirp-chirp..."

[911nut]

I re-did my SC with PB all around. Couldn't detect any increase in harshness.

IMO, if someone's not a DYI guy or into maintaining their 911 to a high standard they shouldn't go for PB. Actually, they probably shouldn't own a 20-25 year old 911, for that matter.

Island, you doth protest too much.

Maybe you secretly admire Chuck. After all, we've all been witnesss to Chuck's establishment of a sucessful business post-retirement which provides him with an income that allows him to build the cars of his dreams. Who wouldn't want to "be like Chuck"?

[burgermeister]

Originally Posted by dd74

Plus why rubber would be better in this instance, even as it deteriorates. I promise to read devoid of bias. Oh, and please explain in layman's terms.

If you park the car, the metal will outlast the rubber. The rubber will deteriorate from age.

If you drive it on real roads with real grit, the metal will wear (sliding interfaces) while the rubber will not (no sliding interfaces). If you grease it often, it might take quite a while to wear, but it will wear. Even balljoints don't last forever, and they are sealed quite well and use very similar technology as PB bushings (greased sliding interfaces). My old Firebird was on its original 1971 rubber bushings, working quite well BTW, but 2 of the balljoints had gone south and gotten quite sloppy.

Once again, I have no gripes or negative things to say about PB's. I have little interest in an electronic pissing match ...

But Global Warming??? It's a religion, with heresy as its capital sin. I know little of climate modeling (though I know enough about other modeling to know humans have no clue about modeling climate on earth), but anytime some system of beliefs reacts so violently against naysayers, I get very, very suspicious.

The only real solution is 4 billion fewer people, or significantly reduced standard of living for 911 drivers and others in the developed world. I'm not willing to kill anyone, and I don't want to live in a small tenement & walk to work either, so I guess I'll let time figure it out for me. Any oil I don't burn, some guy in India or China willbe happy to...

[Thrlls]

Originally Posted by jonbot

Woody, I considered writing you this in a PM, but since you've publicly voiced your opinion, I don't see why I shouldn't either.

Frankly, I questioned the tone behind a couple of your posts in my thread. It's obvious you think my concern about the ride quality, or the maintenance schedule, is humorous. That's fine you think that, but other posts on here have revealed that I'm not alone in my concern. Overall, this may not be as important of a decision to you as it is to me, but you should still respect my attempt at doing research before spending money.

I'm not angry with you or anything, and I enjoyed meeting you at the Bruce Anderson maintenance class, my first impression was that you are a nice guy. Therefore, I'm trying to take your input as you only meaning well, but it's hard to when I feel that my attempt at doing research has become your joke.



Jon

Jon -
No offense intended to you or others.
I'm sorry that you feel that way.
Keep in mind this is a public forum for opinions regardless who starts a thread.

It just seems there's a pissing match as to who knows more about what.
We're talking about a sports car and there is bound to be some NVH no matter which way you go.

I think it's great that you want to investigate before purchasing, and I'm sure that's one of the reasons you went to BA's class, to learn more.
However, if you look at this thread it's like beating a dead horse and it basically comes down to what YOU really want from your car.

My tone is no different from when you met me, and I'm not making a joke of you or your investigation...it's just my opinion, nothing else.

So please don't take what I say so personally...although I'm flattered that you do, I'm really not that important.

[jonbot]

Originally Posted by Thrlls

So please don't take what I say so personally...although I'm flattered that you do, I'm really not that important.

Woody, I did take what you said personally, but belittling comments don't help my research.

Jon

[ianc]

Jon,

This thread is kind of no-win situation, because no one else is you, or can tell you what you can or cannot tolerate for noise in a street-driven car.

I did PB's in mine, but my bushings were original, and I also went with stiffer torsion bars at the same time, so it is difficult to isolate exactly what changes were due to what components. The ride is stiffer and less isolated than it was, but I don't have a problem with that.

As chuck said, each product has its strengths\weaknesses. It seems hard for me to believe that PB wouldn't create a little more noise in the car since it doesn't isolate as well. However, it also seems hard for me to believe that it won't produce a better-handling, more controllable car, as there is less movement and flex in the suspension pickup points.

Only you will know what is an acceptable to you, and only you will find that out by getting a test ride in a car equipped with PB's. I would volunteer to give you a ride if you're ever out San Rafael way. Good luck with your decision.

ianc

P.S. Go easy on Woody. I don't think he means any harm and he has given you a graceful apology. When you ask for free help or opinions here, you take what you get in return, within reason of course. Regards.

[RWebb]

Ian's makes a very valid point about the different factors that need to be partitioned to really answer this question. Otherwise, they can confound analysis.

Here is another:
"I re-did my SC with PB all around. Couldn't detect any increase in harshness."
- But the SC probably did not have new rubber on it at the time. Instead, it most likely had old rubber that was time-hardened and perhaps worn, and/or cold-flowed.

I have the PB bushings but have not yet installed them on my car - waiting for some warmer days. I do not expect to be able to tell the difference from new rubber as my car doesn't have it. It has Neatrix or similar from one of the 6 PO's. I've lubed that but expect the PB will ride better. I intend to go down 1 mm in the torsion bars too (22 to 21 hollow Elephant ones) and that is a confounding factor.

I think the best way to assess the issue for most will be to see if anyone reports unhappiness with a PB install. I don't recall ever having seen that. And, if you try them and don't like them, they should be easy to sell with pics of the surfaces.

[KFC911]

Without opinions, this place would be boring, and we like to beat dead horses too . I think I'll go start a chip thread and see what Loren's up to.

[911nut]

Ever notice when certain people express opinions here everyone goes "ohh" and "ahh". Everyone else gets told their a dumbass.
Bottom line - my car rode like a high performance sports car before and after the bushing replacement. No detectable difference. This ain't rocket science - it's grown men playing with cars.
Take that with a grain of salt or believe it to be gospel.

[livi]

Originally Posted by KC911

I think I'll go start a chip thread and see what Loren's up to.

Those were always great threads. I miss that spicy language of Loren!

[Dennis Kalma]

Just to add one more voice to the story.....I upgraded to polybronze a year or so ago from stock rubber that was in quite good condtion. If anything the NVH was a bit lower afterwards.

The largest increase in NVH came a few years before when I went to Bilstiens, stiffer torsion bars (21/26) and stiffer sway bars front and rear. The car went from fairly compliant and nice to much harsher over small road imperfections and a lot more "N". From what I can see/hear, the heim joints in the sway bars are the biggest offenders with the stiffer torsion bars coming in second.

Now on the good side, at high speed (200kmh+) or even at highway speeds, the car is much more controllable and stable, takes the road imperfections with aplomb and is basically a much nicer car to drive at speed...but at slow speed in the city it is a pain on both ends of the spinal cord.

If you read Frere, Porsche tried a fluid filled block (Fluidbloc's) and found that the fluid squeezed out over time and load, resulting in a rock solid suspension. They then changed to the more traditional Flanbloc rubber bushing which worked better over time. The advantage that Frere stated was that the Fluidbloc's contribution to spring rates was very low...similar to PB's....whereas the Flanbloc had to be figured into suspension rates and deteriorated/changed with time.

While I can see risk with PB's with regard to potential for wear and grit causing problems, in my mind those are minor. In terms of increased NVH, yes, theoretically I can see it, but in my experience it was negligible, perhaps only as it is being overshadowed by my heim joints and stiffer suspension. I mean, when you look at the rubber that is used in the stock suspension, it by no means is soft, it is pretty hard and stiff.....

Dennis

[Bobboloo]

My car is a street car. I went with PB up front and Wevo rear spring plates. I much prefer the ride over the stock rubber bushings. Even going to larger torsion bars didn't make that much difference. What did seem to make the ride more harsh was when I went to Bilstein Sport shocks and bigger anti-roll bars.

[burgermeister]

And any way you slice it, I think Chuck Moreland is a great guy. Anyone who makes parts to keep these clunkers rolling is a great guy in my book, and Chuck gives you the option of staying stock or changing to a stiffer setup, whatever your preference be, and either option at less than 1/2 the cost of factory parts - what more can anyone ask for???