Has anyone gone from new rubber bushes to poly bushes (or si

[jonosx]

After a few days of driving around on the IL bushes i'm happy i went with them.

NVH increase is pretty small in my opinion.

But there has been a big improvement in all other areas over the 200000km old OE bushes.

[StanTheMan]

Patchy has the Poly urathane ones. They are far too stiff for a road car. I also have the offset ones. don't bother. Certainly not on a road car.
Although I really CBF these days. If I had to change it again, Id go OEM.

Its al very subjective. When I changed them Patchy had done just over 200 k km. It went from sooper loose to sooper stiff. If you want a good handling car on the road. I'd steer away from them.

[sailaholic]

Which ones brand wise?

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[StanTheMan]

Which ones brand wise?

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mine?

Mine are Super Pro at the time of installation (2007) they were the ducks guts..
LOL there was a group-buy here on the forum. I cant recall who originally organized it but it did go through MX5 mania. I think they did 25 sets.

[sailaholic]

Bummer, hope my email experience is better with them then.

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[PhilM]

EDIT on my previous post - the Poly bushes I tried and found too hard were Energy Suspension not Superpro - apologies

[sailaholic]

Good to hear, energy suspension are known to be much stiffer.

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[wozzah1975]

The biggest problem any suspension bush is the relationship between the rigidity/design of the bush and where people use it in a particular suspension set up.

A great deal of thought needs to go into how the particular bush you are replacing needs to function and move.

For example, a traditional 4 link set up with a lateral link.
http://nolathane.com.au/susp_ident_images/10.jpg
On a set up like this the bushes in the upper and lower trailing arms need to
-control the differential castor angle and twist under load
-be able to twist to allow the body to "roll" left to right

Fitting hard bushes in these set ups whilst excellent for controlling the castor angle completely ruins the twist required for the rolling motion, as the bush binds under this load and doesn't allow the suspension to act the way it was designed to. It turns a neutrally balanced car into an oversteering pig.
The flip side is the rubber style bushes with a moulded in centre pin are also not ideal. When the suspension travels up and down the rubber bush binds between the moulded pin and outer shell, however the rubber compound is generally more flexible for the body roll motion. What is required is a well designed bush that has a pivoting centre pin, rigid castor control, but flexible twisting control, so a great deal of thought needs to go into what you fit.
On the lateral control (the watts link in the example above) however we need the bush to only pivot up and down with no twisting required, and the items also need to keep the differential as central as possible, so a hard bush with good pivoting properties would be required there.

The bottom line is when you buy bushes look at your suspension set up, and how the item you are replacing needs to move and pick a bush design and material to suit.

IMO.
Hard urathane style bushes are excellent when used for
-Sway bar "D" bushes
-Areas where pivoting only is required (providing the centre pin rotates nicely and not to firmly)
eg:
http://nolathane.com.au/susp_ident_images/22.jpg

Softer style urathane and rubber style bushes are better for
-areas of the suspension that need to retain twisting forces (the 4 link listed above is a good example)
-areas where bush movement and flexability is required

Something to also take into consideration is road noise, as firm bushes will amplify road noise and harshness through the car.

Cheers
Woz

[PhilM]

The rear lower wishbones on the NA & NB( not sure about the NC) front and rear bushes have separate part numbers because the rubber has different hardness - front one softer. This is designed to give a steering effect to the suspension when a side force is applied. That's why they hang on in a corner better than you expect compared to other cars you have dríven and puts the smile on your face!
The OEM bushes are designed with a "crush" centre bush and the OD is extremely a tight deflection fit in the wish bone. This gives the bush torsional resistance - they have to be tightened when the load is on the wheels. The bush is part of the designed spring rate.

[Pamex]

I went to poly (Energy Suspension) a while back. They're ok, no noticeable difference though. I just needed to replace some bushes so went with them.

Currently, I'm doing a full strip-down rebuild of my MX5, and as I have everything out (crossmember etc.) I'll be going back to rubber bushes. The thought of re-greasing them in a few years isn't attractive. I don't want to have to take the car apart again anytime soon. Everything is apart, so I might as well do it all now.

Wozzah is correct though, you have to use poly for the correct application and you need to install them correctly.

[chefie]

well the jury is out on poly V Rubber and it is a tuff decision to choose what is the correct bush for this type of car that has many applications. My NB8A had 200K Klm and is not a DD and mainly Track in qld and on its old frozen rubbers and needed a change ( rear drivers side was frozen 40mm lower than passengers)

after a bit off budget consideration, i have purchased and just installed a set of black prothane Poly bushes, i used a synthetic grease from castrol and coated the external of the bush in the sticky stuff and coaled the inner bushes with lots of LCL castrol grease,

The job took two days including painting the wishbones. I didnt quite get the wheel alignment i wanted caster max at 4.5 and camber a -1, it may take some time to settle in Toe in was Ok

Immediate feel is better response and lighter steering, NVH is significant and it feels like the teins are actually now.

i struggled with deciding to install Zerk fiitings as per FM recommendations and decided not too as if im not happy ill go back to rubber

Ill update after next lakeside in July as per the feel and results