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

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mitch_f1
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Has anyone gone from new rubber bushes to poly bushes (or si

Postby mitch_f1 » Mon Aug 27, 2012 6:13 pm

So my bushes are old and crap, and I am thinking of replacing them, but I am torn between new OEM rubber ones, or getting poly (or similar) bushes. I know that poly bushes are supposed to be better for handling, and you can get the offset ones, but I've heard they need to be re-greased and all that jazz, so require more maintenance than the rubber alternative. So I was wondering if it is really worth the hassel? I know that Daniel Deckers swears by new rubber ones over poly ones, and he runs a number of very successful race cars???

I know there are a million other threads on this topic, but I am asking if anyone has dríven a car with brand new rubber bushes, and then dríven a car with poly bushes? Is there much of a difference?

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PaulF
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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby PaulF » Mon Aug 27, 2012 6:28 pm

PhilM put poly bushes in his NA6 and hated them, and almost immediately pulled them out again and replaced them with OEM ones. There are people who swear by both.

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Hellmun
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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby Hellmun » Mon Aug 27, 2012 7:36 pm

The stiffer the bushes the faster you get feedback which some people enjoy (read increased NVH). The bigger advantage is you can run offset bushes and get more camber on the front which might gives you a little better use of your tyres on a street car. Full blown race-cars won't need that though, slicks need the 4+ degrees range of camber and you'll need to modify the arms for that level of adjustment making bush changes pretty irrelevant by then. I've only re-greased my bushes once in 5 years, they get squeaky when they get dry so it's not that chronic. Personally I think I got 45 minutes of additional camber which was just enough to get good even wear on my RE55's at the time.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby manga_blue » Mon Aug 27, 2012 8:18 pm

OEM ones are not the only rubber bushes on the market. There are stiffer sets made by IL Motorsports and Mazdaspeed. The IL ones are a fair bit cheaper than OEM.

http://www.good-win-racing.com/Mazda-Pe ... -1067.html
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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby koop21 » Mon Aug 27, 2012 8:58 pm

i have full poly bushes in my mx and my mate has stock bushes (not brand new) in his and we have the exact same suspension but my car feels 10x stiffer than his even though we use the same damper settings. With full poly bush it will make your overall setup alot stiffer and forces you to use stiff damper settings and harder tyres so the car feels intact, if you dont the car does feels abit sloppy.
I have not re-greased my bushes since i put them in about 6months ago, and i have read about people putting zerk fittings but i dont think thats necessary considering i got bushes with embedded with graphite which apparently helps with lubrication.

If only a few bushes are destroyed i suggest you just replace them and save yourself the trouble of rebushing your entire car.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby sailaholic » Mon Aug 27, 2012 9:00 pm

My Last car rusted away befor the poly bushes squeaked, we just de registired it last month, and the bushes went in 8 years ago (super pro). We did smother the mating faces in the provided grease though - as per the instllation insturctions)

I think the squeaking factor is pushed by the bushes detractors or made worse by cheap component or impropper install.

I've also had poly bushes put in the work commodore, 40km down, in quite a heavy car and they are still quite (super pro again). However i havn't talked to any suspension shops that recommend DIFF MOUNT BUSHES in urethane for street use. One even went as far as to say a super pro rep also didn't recommend it in a street car due to all the vibration transmission.

I'd say the IL or MS ones would probably be a good mid ground, see if you can find a hardness rating for them, that will help.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby jonosx » Tue Aug 28, 2012 1:13 pm

I just ordered a set of IL bushes from MX5 parts UK.

They were a bit cheaper than the others at $365 delivered.

Will see what they are like when they turn up and are installed.

I have had superpro before in my last car and they were ok, but i see too many poly bushes split, burst or squeak. Plus the eccentric ones are also prone to self adjusting.

Cant argue with the price of the IL kit and being OE style rubber, just a bit stiffer, they should work well.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby sailaholic » Mon Oct 01, 2012 8:36 am

I came across some information awhile ago that said rubber bushes actually harden up as they get older. Obviously their effectiveness goes down once the bushes crack and split.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby Mr Morlock » Mon Oct 01, 2012 10:43 am

on another vehicle I removed rubber bushes from shockers that were 25 years old and no sign of perishing apart from cracking around exposed areas. Rubber is a spec item an OEM is probably better than aftermarket insofar as requirements and conformance is concerned. Many people just want a good riding car and not looking for a few 10ths on a track or a road. PS of course rubber deteriorates over time- but so does everything else including all plastics. PS a rubber bush is probably more expensive to produce than a "poly' product.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby jonosx » Mon Oct 01, 2012 10:51 pm

Well i've just fitted the IL bush kit. Only dríven it around the block so no real feedback on ride, handling or nvh yet, but will let you know. Although it must be said i didnt notice any drastic changes to nvh in the short drive.

But i was impressed with MX5 parts UK service, i ordered them on a monday and they arrived thursday. I deal with some suppliers in Sydney who cant match that.

Product was also really well presented and packaged and all fitted with no dramas. So much nicer than any poly bush i've seen.

Interestingly pretty much all of my arms had "walked" on the original bushes and on two of them i actually had metal to metal contact between the arm and the chassis mount!

There was also significant evidence of fatiguing and cracking in the original bushes that was more evident after they had been removed. But i guess 200000kms will do that.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby Okibi » Mon Oct 01, 2012 11:01 pm

How did you go pressing the bushes in?
If you had access to a car like this, would you take it back right away? Neither would I.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby jonosx » Mon Oct 01, 2012 11:20 pm

Okibi wrote:How did you go pressing the bushes in?


Pretty straightfoward but a bit time consuming.

The shape of the arms / position of the bushes doesnt really make it particuarly easy to use a press to do them.

So i just used a long threaded bolt, big washer with a nut welded on it and a couple of lengths / diameters of tube and the ratchet.

Plus this lets you do the bush in the rear knuckle on the car.

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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby slug_dub » Mon Oct 01, 2012 11:24 pm

Bushes... I hate them... I hate them so much!

Used a tool like you've described last time but they were still brutal... I can't believe I'm going to do it again on the second car... why oh why??!
Those IL Motorsport ones might be the go for me this time.

Sorry for the ranting have been changing bushes on a Jag this weekend... didn't finish... took years off my life! :mrgreen:
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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby trader » Wed Oct 03, 2012 2:09 pm

I have just replaced my bushes after 110000 with OEM. I actually bought a set of flow flex bushes but went away from them after reading many posts about squeaky bushes. Rather wish I had stuck with them though as while the new OEM's are supple I think they would have been more precise as I have dríven in a car (not mx5) with poly bushes. Anyway if you're interested my kit is for sale (with zerks) for $150 plus postage (I used the front bushes though)..
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PhilM
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Re: Has anyone gone from new rubber bushes to poly bushes (o

Postby PhilM » Fri Oct 05, 2012 10:40 am

After reading plenty of posts -I went superpro and after 1 WPk track day including the 600km round trip and a weekend run to Armadale decided to replace them with OEM due to the harsh & jerky ride around bumpy roads - I did not like driving the car anymore. It did feel more direct in the steering but it did not return much better track times as the tyres did not seem to follow the road as well.
The friction on bushes alter the spring rates and when they were removed, I found the lubricant that came with the Superpro had gone waxy increasing friction. I would suggest using a different lubricant!
The OEM bushes allow the rear to change the toe in when corner loads are applied.
If I were to do it again I would use the stiffer rubber bushes in the front lower arms.
BTW even though I have a hyd press I ended up using some bits of pipe with a welded end plate and a 12mm bolt turned by a rattle gun but its still a pain in the butt and a couple of days wasted.

I know Hellmun gets great results but it would be interesting to know what the other fastest MX-5 s are using.
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