Control arm bushing options 2015

[faverymi]

Need to do control arm rubber bushings on the ice cream getter 911 87 carrera.

Car is shiny and besides spirited driving, it doesn't see any track time at all.

All I can see is URO for really cheap that I don't want to use and the Elephant that I find a little spendy for 4 pieces of rubber.

Are there any other options there? Is there a "in between" option.

Thanks in advance.

[JacobS911]

I think the ER rubber is your best bet, and would be worth the extra $$ if not going full poly-bronze route. Plus replacing almost 30 year old rubber will be a pretty dramatic difference in feel. Wait for pelican to email you a gift certificate/promo and snap em up then or I'm sure another pelican has one that they aren't going to use

[Craig_D]

Go with the ER sport rubber. This isn't an area where you want to save a few dollars, it's important to have good rubber there. With bad quality or worn rubber, people have experienced worn torsion bars which will cost you a whole lot more to replace.

You don't have to have a track car to benefit from good rubber bushings either. You'll be happy you went with ER rubber bushings. I highly recommend them for your use.

Cheers,

- Craig_D

[chris_seven]

Buy them from Porsche 914.341.422.00 - $16.00 each and are very good.

They are a SOB fit but do the job well.

[911obgyn]

I replaced mine with URO because I was on a budget 2 years ago. Now I have to do it again they are off center already.

[Craig_D]

The cheaper way isn't always the better way. Do it right, or don't do it at all.

I did a ton of research before my suspension rebuild, and went with ER rubber control arm bushings because they were the best bang for the buck (meaning best rubber bushings, and at a reasonable cost).

They may be four pieces of rubber, but they are important four pieces of rubber.

Good luck.

[monkeyodeath]

I thought that the bushings themselves were not available individually from porsche? Is that not the case?

I can attest to the ÜRO ones being ****ty. The car I bought had the CABs replaced with ÜROs a couple years back and it was already squeaking like a whorehouse mattress.

[chris_seven]

Originally Posted by monkeyodeath

I thought that the bushings themselves were not available individually from porsche? Is that not the case?

The individual bushes have been available from Porsche for at least 10 years and we have used them for the last 8 years with very good results.

They are only shown on the 1965/1969 section of the PET and they have a 914 part number.

They fit correctly with a significant amount of radial compressive stress and they stretch from 35 to 55mm long during installation.

The radial compression affects the static modulus of the rubber and improves control arm location without influencing damping. The bush has to stretch as rubber is incompressible so as it is forced over the control arm it must elongate.



The URO Parts are just a simple slip fit which means that the bush does not locate the arm very well even when new and when the rubber deteriorates slightly it doesn't work well.

[3literpwr]

These have been working good for me.

PowerflexUSA - 911 (87 - 89)

[faverymi]

Originally Posted by chris_seven

Buy them from Porsche 914.341.422.00 - $16.00 each and are very good.

They are a SOB fit but do the job well.

Thank you Chris!!

URO was never an option. Im refreshing 2 street car's suspension this coming winter so a little savings without quality compromise is a big plus

If Porsche parts lasted 30 years, can't go wrong with them.

[chrismorse]

Part of the cost is the tapered bushing that centers on the control arm. This allows the new bushing to be pressed on to the arm.
Chuck has a good video showing the installation process.

He also has another clip showing testing and deformation of "other" bushings, probably the uro items.

Also available are "sport hardness" rubber control arm bushings. I haven't seen any feedback from users or any analysis of their merit.

Chuck also offers "sport hardness" rear trailing arm and front upper strut bushings which I opted for but the car is not yet together.

chris

[chris_seven]

Originally Posted by chrismorse

Also available are "sport hardness" rubber control arm bushings. I haven't seen any feedback from users or any analysis of their merit.

chris

The ER website only offers one type of bush for the 69-89 Control Arms - 'Sport' bushes aren't offered but if they are available 'on demand' it may be interesting.

There is, of course, as with any engineered product a compromise in various aspects of a material's performance.

The hardness of an NBR rubber tends to be directly related to the amount of carbon black added to the compound.

Although the hardness of the rubber increases with carbon black its resistance to taking a 'set' tend to reduce and the material will generally become more brittle and accumulate fatigue damage more quickly.

I am sure that from an initial performance and handling point of view harder bushes are a good idea but I believe that they will deteriorate more quickly than softer bushes.

The decision about what to fit, as always, depends on the benefit you are looking to obtain.

Some modern developments in NBR are using carbon black additions produced from natural gas and these tend to offer much better and more uniform properties but at a significant price premium.

We have recently been making some Camber Plate Bushes for 1965-1970 cars using an HNBR material as this seems to have better long term durability for a given level of hardness but dis add 50% to the cost of the bush.