evoderby

What is there to talk about? Bill's observations are valid as far as the available choices go, and the relative merits of the three options.

What I do not agree upon is the theory of urethane bushes having reduced longevity or the tendency to squeek. A theory is only as good as the way in which it is able to reflect a broad enough set of empirical data....i.e. real life. We have a very broad set of Walrod users on here and none of them have reported any such issues....

Imo it comes down to personal preference, rubber is fine and sticks closest to the Porsche way....walrod bushes are fine as well and provide a swift engineering type of approach;-) The latter being a more cost effective solution doesn't make them an inferior product!!!

Again, the ultimate solution is down to personal preference....

IXLR8

Bill, how do they compare to the Elephant Racing "sport" hardness?

kclipse

Installed Chris Walrod's front bushing two weeks ago, and it really tightens up the steering. No increase in NVH!

Bill Verburg

Elephant sport is the same as RS

To those that think p/u won't wear or squeek do some research, I've had them on other cars and will never use p/u again.

If you want zero deflection & zero friction on your race car use mono-*****, if you have a street car use rubber.

If you know better then use p/u

evoderby

Bill what research do you suggest I do other than drive my 964 hard for the past 10K km with Walrod bushes fitted up front??? Again, still performing like the day I fitted them...add to this I'm not alone in this experience given the countless happy users on the forum

Not all pu bushes are created equal it seems....

Bill Verburg

hmmm, That's a tough one,, perhaps start w/ the Weissach engineers. Have they ever used
1) rubber
2) mono-*****
3) p/u

answer for the lazy(but do look into it anyway)
1) yes, street & race
2) yes, street & race
3) no

IXLR8

I've read that in a couple of posts here.

I hope you realize you had a shimmy because you had "worn" suspension components and that if you installed any brand bushing, the shimmy would have disappeared (provided no other suspension components are worn).

My OEM original bushings have some 40K+ miles on them. My 993 does not shimmy, but when it does, I'm sure the Elephant Racing bushing I intend to install, will cure it, just like the Walrod or PowerFlex bushings would have if I chose those.

chris walrod

Bill is a tremendous resource AND asset to this forum and indeed Bill is a great contribution through experience building an awesome 993 over the years!

With respect to the bushings I offer, there have been zero complaints of squeeking. That said, there may come a day where it will occur. Regreasing is a relatively easy and quick fix, should it ever happen.

PU bushings not lubricated with grease developed especially for this application will squeek! No doubt about it. Kits I've installed in the mid 80's in other cars did make noise as they were installed dry.

There are many choices that range from mild to wild and really there isnt a wrong option out there. Just a matter of what one intends to do with their car.

evoderby

Interesting concept, let's stick with the Weissach engineers just for the moment. Have they ever:

1) dressed in Lederhosen
2) dated German women
3) slept with Doutzen Kroes

answer:

1) yes
2) yes
3) no

Following your line of thinking this gives valid proof that wearing Lederhosen and dating German woman is the thing to do whereas sleeping with Doutzen isn't (even to the extent where it's not recommended(!)).

Let's face it that without scientific proof the above is nothing more than opinion. You're definately entitled to have yours, however please do not present it as fact.






To add some facts:

Sticking with the Weissach way of using rubbers definately is a safe bet and a good one at that, but doesn't come without some inherent compromises (just like PU). Scientific fact is that rubber starts to degrade from the moment it's vulcanised into the suspension bushing under the influence of ozone, a process which is further accelerated through exposure to water and oil amongst others. For this reason we see 10 year old rubber bushes with only as little as 15K miles that have degraded to the extent in which they get torn loose from their metal sleeves. Already when new, rubber is more pliable than PU.

Compared to a new rubber bushing the PU type gives firmer geometry control at the expense of NVH. It is totally unaffected by ozone and therefore has an unlimited static life. In it's dynamic life the bush relies on sliding action, rather than the torsion spring type action the rubber bush relies on.

It comes from the latter that PU bushes are said to suffer from accelerated wear and squeeking. In fact this might be the case with many of these bushes. Empirical data gathered from a large group of RL-ers has shown that the way in which the Walrod bushes are designed, with lube chambers containing special grease, that these do not suffer such effects for many years to come with the sort of mileage we typically put on these cars (again years don't effect them, only mileage).

This only leaves the matter of stiction: rubber bushes are said to give less resistance to suspension articulation and therfore give better performance in this area. While I'm able to clearly notice the difference between rubber and PU in geometry control, personally I haven't been able to notice any difference in stiction between the two....this could either mean the effect is insignificant, or I am too insensitive to notice any effect in this area. Which brings me down to my personal opinion:

I like the increased geometry control of PU over rubber, I can't care for the increased levels of NVH (my 964 isn't limo quiet anyway) and with 10K active km's and still going strong these bushes are giving me exactly what I have been looking for. If rubber suits your needs better, choose rubber....THE END

993Porsche

Is anyone driving their car as a DD using Walrod bushings? And approximately how many miles are on those bushings?

Thanks,

Ken

Kika

my car is a DD, well, may every other DD, but it is a street car, and does no track duty. my former SC did see some track time. I had the Walrod bushings installed about 2 months ago when I put new tires on, and had a corner balancing.

I have only put a few hundred miles on since the work was done, so it is all relatively new.

I have not heard any squeeking or additional noise, nor would I anticipate any at this time due to the newness of the install.

Overall, handling is definitely crisper, although it is difficult to say which of the three things had a greater effect, the sum of them is great however.

For my personal use, the PU bushings were what I chose due to RL use of them (large number of good success) and price. Nothing lasts forever, so when the PU bushings wear out, or need grease, I will simply have them replaced.
For a street car, monoballs did not seem like the right path, and rubber needs to be replaced at some point as well, maybe sooner, maybe later, but still replaced.

I realize Porsche has much more data and experience to rely on to build their cars than I do, however, just because the factory did or did not do something does no necessarily mean it was strictly due to performance reasons. They have to turn a profit and build the vehicles, so cost and manufacturing are also entered into the equation when it comes to decision making.

IXLR8

Just curious Kika, what bushings were installed before you replaced them and how many miles were on your car at the time?

BTW, Porsche also chose what they did for long term use so that owners can use their 993s as a daily driver.

mongrelcat

Yes. ~30k miles and 2.5 years since installation, lots of wet exposure being in the PNW and no issues at all. "Is this a great place or what?"

Kika

my car ha d 90K miles on it when the front control arm bushings were replaced. They were the original bushings.

IXLR8

Thats good news. Thanks for the feedback.

Did you replace them because they were totally gone, or you just wanted to take on a project?