DDK - Die Deutschen Klassiker

Hi
Does anyone have any experiences/recommendations they can share in relation to suspension bushes? Specifically, I'm thinking polybushes for fast road/track day. Something that doesnt squeak and drive you nuts is preferable! Elephant does the polybronze stuff with a grease nipple- anyone used those?
Cheers
Will

Hello inch

I considered it for my suspension when doing the refurb and drove a car with harder bushes - didn't like it for a road car at all. Even a 50 / 50 road / track day car I would stick with standard myself. Different forba race car.

What is on yours now?

I used them every day on the car for about 8 years. Some people have had problems with then squeaking from the getgo but I've only found them squeaky if I don't keep them greased up - a good greasing up generally sorts them out. Most recently I've changed the fronts to those elephant racing sphericals - feel just as good as the polybronze but no greasing. When fitting you need to make sure they are pulled in tight. I've still got the polybronze on the rear

Don't think they do sphericals for the rear but if they did I'd buy them. When you're driving the car every day greasing the nipples every few months is a ball-ache

I've not found any issue at all with harshness - they only remove lateral movement and sideways 'give' - the suspension moves quite smoothly in it's desired plane. They don't remove the ability for bumps to be cushioned - that will be covered by the torsion bars, shock absorbers and tyres

I believe you can get similar results from the super pro bushes but then again differing stories on squeaking - and if they do squeak you'll need to take them apart to add some grease in.

HTH

yoda wrote:Hello inch

I considered it for my suspension when doing the refurb and drove a car with harder bushes - didn't like it for a road car at all. Even a 50 / 50 road / track day car I would stick with standard myself. Different forba race car.

What is on yours now?

aha! interesting. But then again you drive like a pensioner. A very slow pensioner at that...

whats on there now? looks like standard. Theyre giving no probs, so should probably abide by the aint broke/dont fix rule. Just tempted to try something else. I think Clemmy has poly bushes on the front but obviously the problem there is that I havent seen that car for so long that I cant remember how it drives....

sladey wrote:I used them every day on the car for about 8 years. Some people have had problems with then squeaking from the getgo but I've only found them squeaky if I don't keep them greased up - a good greasing up generally sorts them out. Most recently I've changed the fronts to those elephant racing sphericals - feel just as good as the polybronze but no greasing. When fitting you need to make sure they are pulled in tight. I've still got the polybronze on the rear

Don't think they do sphericals for the rear but if they did I'd buy them. When you're driving the car every day greasing the nipples every few months is a ball-ache

I've not found any issue at all with harshness - they only remove lateral movement and sideways 'give' - the suspension moves quite smoothly in it's desired plane. They don't remove the ability for bumps to be cushioned - that will be covered by the torsion bars, shock absorbers and tyres

I believe you can get similar results from the super pro bushes but then again differing stories on squeaking - and if they do squeak you'll need to take them apart to add some grease in.

HTH

Thanks Mark, I dont mind the greasing every so often to be honest. I have to do it on another jalopy anyway. But it does sound as if the sphericals are just as good...will have a think.
cheers
Will

I installed my sphericals myself and then went to Centre Gravity for setting it up - it was Chris there who explained I hadn't get them pushed in properly. Rebel racing do a similar product but I've always liked the quality of Chuck's stuff.

Both the sphericals and the polybronze are lovely things - feel nicely engineered

I fitted SuperPro bushes to my 2.4E but went with standard neatrix rubber on the Mongrel based on the recommendation of Gary Cook - imo the neatrix is way superior as far as feel/handling/ride is concerned and I'm switching to neatrix on the 2.4E as soon as I get the chance.

I have polybronze front and rear on my 3.3 turbo (which i drive on the street very often) as well as on my RSR rep (which I mostly drive on track and I drive it hard). No loss of comfort to speak of no squeaks and a much better working suspension (tigher, more precise, better location, less flex and play).

Take care however, when you fit the fronts. They have to be perfectly aligned in order not to bind.

Small niggle: Elephant supply conical washers that are supposed to help achieving an aligned fit. They do in theory but the material is so brittle that it breaks when torqued up (to the OEM value). I had some made in a proper material.

The sphericals help with that alignment issue at the front because they rotate in several axes

FWIW:
Had my 73T for 28 years on the road, with 14 years of them road/hillclimb.

Have had 'polybushes' in the rear plates for 26 years, no squeeks all ok. Lubricate with WD40 once a year.
Have had Superpro in the rear banana arms for 23 years, all ok, no noises, no maintenance.
Front A arms had nylon, squeeked. Superpros don't. Zero maintenance.
Had spherical top mounts for 18 years or more, replaced with Superpro and all good about 6 years ago.

Have Superpro in the front drop links and fr/rear anti roll bar mountings.

TBH I think the stock rubber bushes are quite good enough for the road as Bob Watson told me after I'd done all the above!

I know this isn't a 911, however I have strongflex all around on my e30 - fitted about 2 months ago, and they're great - about 2/3 of the price of powerflex (which I have throughout on my e36) and just as good in my opinion. infact they've got really nice texture machined into the lubricated faces to retain the grease which I think will work much better than the smooth powerflex ones - time will tell!
Not sure they do anything for the 911, but might be worth a look

Superpro all round here for nearly 7 years, never squeeked.

Cheap Casting Grade Polyurethane - all the wrong properties to do the job of a suspension bush.

Try PU bushes on a lightweight car if you want to find out how they ruin ride characteristics.

I fitted a set of Powerflex Bushes to a Lotus even a few years ago and it shook like a wet dog. kept them in place for a week and threw them away.

The real problem with PU is that the casting grades behave very much like an elastic solid and have very limited visco-elasticty at even modest frequency.

This means their damping characteristics are poor which is evident

The frequency which creates a glass transition of a typical rubber bush is around 10^6 Hz which means that an NBR bush will provide good damping across the range of frequencies normally found in suspension components.

PU will behave like an elastic solid well within the frequency range found in most suspension systems so doesn't really achieve the basic requirements of a well engineered bush.

You have to ask why the Automotive industry spend billions of Pounds every year on NVH work and sticks to materials such as NBR and HNBR for virtually all production cars.

The PU bush industry relies on cheap casting grade materials manufactured at room temperature in cheap tooling and I believe the materials used have been selected for this capability rather than the properties that are required for a suspension bush.

If you are only interested in the basic stiffness of the bush then they may do the job but then you have to muck around with grease because the sliding friction is so dreadful.

Nylon is poor because it swells up and binds when wet but there are many other engineering Polymers that have very low friction and work well

We have been using Tivar 1000 for about 10 years now and we don't have to grease bushes as the sliding friction levels are very low and they align suspension even more effectively than PU.

elephants on my 2.4s for many years ( 7 years + ? )

never squeeked. always run smooth. Greased every few 1000 miles. when all stripped apart a few years ago when getting set up by CofG , they all looked like new.

Can't stand PU bushes! Most OE rubber bushes aren't designed to slip in their housings, the movement is internal to the rubber element hence they don't squeak or wear out the surroundings.

They do perish and degrade over time but don't 'wear out' as such.