Can anybody tell me where I can get these rubbers. Porsche asks 250€ each for these, but I am hoping for other source. Parts catalogue says 901 341 421 03.
Can anybody tell me where I can get these rubbers. Porsche asks 250€ each for these, but I am hoping for other source. Parts catalogue says 901 341 421 03.
member 2971 Jacques
911 March 1965
912 April 1965
911 May 1965
964 RS clone (one of many)
964 Targa original Dutch police car (one of 45)
964 Turbo 3.6 (one of 1450)
993 S Vesuvio (one of 250)
1966 911 #304065 Irischgruen
Got it on stock at 100€ each
and guess what , they are the same as Po..... have, so a nice save :-)
drop me a mail if you are interested at early911parts@gmail.com
Marek
PS those Elephant ones also got my fingerprints on them
I noticed they cut of the logo and stamp there own logo :-)
Elephant racing also has a new spherical product - looks ot be the very best thing out there
I have been quite interested by the 'spherical' joint but can't quite work out how it functions.Originally Posted by 37yrold911
I don't understand 'Static Binding' . If its not moving why does it matter?
If the control arm mounting points are misaligned than the chassis is bent and should be straightened.
I can understand that if there is significant misalignment it will be difficult to fit the control arm if the bushes are hard and not compliant but if this is the case then remedial action should be taken to eliminate the cause and will allow the arm to bolt up correctly without being misaligned.
The Dynamic Binding is more complex.
It is true to say that if the suspension on the car flexes significantly the hard bushes may bind. The amount of movement required for these forces needed to overcome binding would be quite substantial and I would expect to see significant fatigue cracking of the body in the area where the housings mount to the body.
I must say in the last 10 years of building and repairing competition 911s fitted with hard bushes I have never seen cracking in this area of the suspension pan.
I would also believe that the control arm is much stiffer than the floor and when bolted up with a hard bush will help the floor out and reduce any movements.
If the suspension pan does 'hog' or 'sag' it will change the axial force being applied to the spherical seat and this must in the limit cause them to jam.
I am reasonably confident that when used with a 'straight' control arm and a correctly aligned suspension pan that the hard bushes of the type provided by Rebel Racing and a number of other companies work well and do the job.
I have to say that I am not convinced by these parts but would welcome a detailed discussion.
I would also admit to a vested interest as we have made hard bushes for front control arms for the last 7-8 years and we are now just starting to produce our own range of rubber bushes.
We make the hard bushes from a bearing Grade Polymer supplied by Quadrant Plastics and an Electroless Nickel Plated Sleeve which is a press fit onto the control arm. The sleeve is heat treated to improve the hardness and wear resistance of the Electroless Nickel.
Unlike Nylatron they don't change volume when wet and they maintain a high impact strength down to -100degC and are very cost effective.
We have had them in use on a number of Competition and Trackday cars and they function and wear quite well.
We make one of these bushes to use in place of the 'FanBlock' used between 1965 and 1967.
When used in conjunction with a Rubber Bush on the front of the control arm and a rubber camber plate bush there is no discernible impact on ride of vibration.
You leave the thick wall inner sleeve - which is real PITA to remove on the control arm and just replace the rubber and outer sleeve.
The 'Rubber Stop' on the other end of the control arm which is still available from Porsche (914 Part Number) also appears to be slightly incorrect.
The part supplied has an overall length of 32mm which doesn't quite fit correctly into the forged steel bracket.
The original bush is 45mm long - we have measured around 20 old parts and are confident of this measurement.
The 'short' bush will work but it isn't ideal.
We have just completed a new compression mould and bushes with the 'correct length' in an HNBR compound will be produced in about 2 weeks
We have the correct camber plate bushes and hardware in stock and these are the correct shape and design and differ from the Koni Damper bush that is often supplied as an alternative.
All I know is that Chuck says they are an upgrade over his Polybronze (which I have and like), and that the polybronze ones do not move dynamically in response to chassis flex the way Sphericals do. He told me that I would not see a dramatic difference unless the Polybronze is having alignment issues, either static or dynamic. I asked how I could determine that but did not get a reply on that point.
It might be interesting for the various engineers making aftermarket products to get together sometime and have a seminar...
I have tried to think through the entire concept of the 'spherical joint' in this location and how to model what is happening.
My first problem is to really understand static binding.
I was involved, for many years, in the design of high speed rotating machinery and test systems.
When tow machines have to be connected there will always be parallel and angular misalignment and the conventional way to deal with this is to use a flexible coupling.
If you try to rigidly connect two machines the misalignment will create a force on each of the supports.
The force generated will be proportional to the degree of misalignment, the stiffness of the supports and the stiffness of the connecting shaft.
In the static world the forces generated by a small degree of misalignment would be easy to withstand and we only have to consider the effort required to install a control arm into the car.
For this force to be significant there would need to be a great deal of misalignment.
I think to describe this as ‘binding’ is unhelpful as the forces created are simple to understand and as no relative motion takes place they can be considered as irrelevant.
Once we start to rotate a machine things do start to change and in a normal machine the dynamic rating of the bearings being used is of great significance.
The forces generally do not change but the bearings are affected by the deformation of both the roller and the track and their life will be shortened.
In the case of a control arm the ‘dynamic’ binding we are considering is due to the road load behaviour of the chassis and the influence this may have on the freedom of the wheel to produce the correct motion.
If we consider a standard control arm fitted with NBR bushes we can easily see that in order to allow wheel motion the bush will have to deform in torsion and there will be a spring rate (non-linear) associated with this bush.
It is also interesting to note that the rubber also reduces the static forces caused by misalignment as it effectively reduces the stiffness of the supports and hence reduces the loads needed to twist the bush as the wheel moves.
I have no idea of the torsional stiffness of the rubber bush but this needs to be added to the force needed to deflect the torsion bar. It may be possible to make a rough calculation using the installed hardness of a standard bush but it is a relatively significant force.
We also need to add the force generated by the damper which will differ in either the compression or rebound directions.
I would imagine binding may have less effect in the rebound direction but need to consider this statement at greater length before coming to any conclusion.
It is, however, only when the effects of binding become a significant addition to these forces that it becomes a cause for concern and I think that the degree of misalignment required would create other and more significant problems.
The spherical joint as shown in the ER sketch behaves much like a spherical seat and this type of device allows misalignment when unloaded but as the axial force increases does load up significantly and in the limit will lock until unloaded.
I am not sure about a Seminar but feel that a Symposium would be a much better bet( Symposium - from the Greek for Drinking Party)
I've been all over this topic in the last month. I've changed my mind on bushings numerous times. I'm now waiting for my 3rd order of bushings to arrive. Here's the link to my woes. (Links are not working this morning - search Front Suspension Project)
Stoddard - I tried them but they sent the wrong rubber bushings. The phone sales person was totally clueless. They've gotten as bad as Sierra Madre lately.
Automotion - They sent me the URO bushings. They shop doing the work on my car declined to install them. btw-They also have some really bad sales reps on the phone.
Rebel Racing - I'm waiting on these to arrive. I didn't even bother with them on the phone. They really need to get more sophisticated about e-commerce. They never even sent me a tracking number. That's after they charged for shipping. Actually they should probably start using eBay or Amazon.
I don't like the Elephant products because they use grease. Grease attracts dirt. Dirt and grease combine to make a wonderful grinding compound.
btw - Pay attention to Chris. He knows what he's talking about.
Richard Newton
Richard these are obviously Fan Blocks.
Is the thick wall tube that forms the inner still on the control arm?
I can post you a couple of plastic bushes that will work in their place providing this tube is still in place.
You can have them with our compliments if you can wait for normal mail delivery from the UK.
We have them fitted to around 20 SWB cars and they do work.
Just PM address details and I will post them out.
My car is a LWB. I'm going to wait for the Rebel parts to arrive. Thanks for you help and suggestions. I'm sure this is going be quite a tale before it's over.
I tend to overthink these projects. Right now I'm thinking about an increase in torsion bar size. I've been in a lot of directions with this car. Street Car to Track Car to Street Car. Right now I'm seriously considering taking a very small step back to a track car. Maybe.
Richard Newton
My 911 Saga
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