since we produce 2 of the 3 products, i have some knowledge. we use delrin
instead of nylatron. delrin has a slightly lower CofF so is a little
slipperier than nyllatron. anyhow, delrin is a rigid material with basically
no compliance (give). we use this for race suspensions where the transient
repsonses need to be accurate and consistent - it's much nicer to have a race
car suspension that reacts the same way on a regular basis.
Urethane (color makes no difference - it's just a pigment) has some give.
depending on the hardness rating (shore is the polymer term but think of it as
durometer) you can have bushings with more or less give. Advantages are the
bushings are not affected by road film, oil and all the other things that will
degrade rubber. the bushings we produce are an 87 shore rating and have no
"filler". some urethane has filler, sort of like soy hamburgers, and will
degrade when the filler migrates out fo the urethane. since we have no filler,
our bushings are not prone to squek or degradation of the material.
rubber bushings, including v8 bushings, like urthane come in varying shore
ratings. problem is the rubber goes away because of its exposure to oil, etc.
the argument that urethance transmits noise, etc while the rubber doesn't is
actually not quite right. when any suspension bushing is put into a loaded
condition, such as cornering, the bushing will give or flex to the limit of the
material and then will basically become a solid bushing when there is no more
give. worst case is rubber bushing. it becomes solid, or set, and then is
predictable. problem is, it doesn't become solid on a consistent basis. maybe
X amount of force will set it solid one time and the same amount of force will
not produce the same result the next time. urethane will also give until it
becomes solid but is consistent in the amount of force needed to achieve this
state. therfore, the handling is much more consistent and predictable. the
delrin (or aluminum, brass, steel, etc) bushing has no give and is extremely
predictable because of this. going straight ahead with no side loads, any
bushig material will work. the "noise" people atribute to urethane comes only
from the fact that the bushings become set solid on a more consistent reponse
basis and you hear the suspension. our urthane without filler does not
squeak. urethane with filler added can squeak as the urethane is not
consistent in its shore rating.
sorry for length and let me know if we can help. thanks, ted
Barrie Robinson wrote:
> Folks,
>
> Can anyone give me an opinion on the difference between rubber,
> polyurethane and nylatron bushings for suspension based on real experience.
> I have been told that the latter two make riding harsh - but that may be
> in comparison to North American boat-ride vehicles. Nylatron was used by a
> friend of mine in a Maserati Mexico and the steering is pin-point. and the
> ride is very similar to a Maserati Mistral so one has to assume the
> nylatron did little to put arshness in the ride. But I would like to hear
> from someone who has had both - preferably in the same car. Nylatron is so
> sanquinary expensive that I do not want to get it only to find it gives a
> go-kart ride.
> Regards
> Barrie Robinson
> barrier@bconnex.net
>
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--
Ted Schumacher
tedtsimx@q1.net
http://www.tsimportedautomotive.com
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