Poly Bushes...a mechanics viewpoint!

[El Saundo]

Engineering is always done to a budget and includes safety factors, plus end products often have to suit a potentially diverse target demographic to maximise sales.

Modding is all about tailoring the car to your needs and making changes the manufacturer deemed too expensive to be worthwhile or didn't have the time/budget to develop and perhaps reducing those safety factors based on the owners desired level of risk. I find it hard to believe changing to poly bushes will have a catastrophic impact on chassis component life, I'd bank on rust killing something first. If making the ride harsher was catastrophic you probably wouldn't get 18" wheel upgrade options with runflat tyres on a car that comes on 16's and large profile as standard.

Edited July 29, 2013 by El Saundo

[CW Racing]

Fitting poly bushes isn't like putting rose joints on your wishbones. Then you would know what vibration feels like!! I think they are fine I had them on my sprint car and drive it to all the rounds and found it much sharper and nicer to drive. Personal preference though

[Dan_Q]

dave brookes? great guy, likes a beer can bl00dy pedal too i tell thee!

agree with most of the above, nice discussion containing most i've heard / read / been told etc over the years without getting heated.

zuban's point cant be ignored- in the case of the supra many of the bushes are spherical and allow movement in a particular direction, in which case a poly solid replacement would be detrimental, and in some cases wear much quicker than a stock bush. BUT- i imagine also that in most cases a set of new poly's would be both much cheaper than toyota replacements and perform much better than an old fucked bush.

yer pays yer money, yer takes yer chance

[ams]

I fitted poly bushes to my wishbones and one wishbone actually cracked - first time I've ever seen that - BUT I fitted them at 100,000 and the one cracked at 213,000 - most cars the wishbones get replaced completely before them

Sort of miles. So might not be down to the bushes.

[Zuban]

dave brookes? great guy, likes a beer can bl00dy pedal too i tell thee!

agree with most of the above, nice discussion containing most i've heard / read / been told etc over the years without getting heated.

zuban's point cant be ignored- in the case of the supra many of the bushes are spherical and allow movement in a particular direction, in which case a poly solid replacement would be detrimental, and in some cases wear much quicker than a stock bush. BUT- i imagine also that in most cases a set of new poly's would be both much cheaper than toyota replacements and perform much better than an old fucked bush.

yer pays yer money, yer takes yer chance

deffo, when you see a pro set up a track or race car like an integra, that's a prime example of it depending on purpose, they will use a mix of oem, poly and spherical bearing where appropriate, for example they retain the oem bushing for the trailing arm, as it has designed in toe control, the upper wishbones on the front will change the steering feel so they may be spherical or oem, and where the bush acts in only one axis, a poly bush is used, top mounts some prefer the hardened rubber as the steering loads don't all go through it so its less of a contributor to movement. A lot of it depends on feel as some people don't want rear steer so poly bushes will reduce that whilst some want it so stay oem. one thing is for sure if you have fecked suspension it will be better and probably help compensate for slack elsewhere.

[BrianGT]

My car is polybushed and also has rose jointed castor arms. It's quite important with polybushes to lube them at least once a year with fresh asembly grease.

The std rubber bushes on TA22 rear links are quite hard already. The rubber is bonded to the eye of the link rods and pivots around the mounting bolt but that seizes over time so really all that is happening is that the movement is limited to the amount of twist or give in the rubber.

Polybushes don't attach to the eye and so can swivel in the eye and on the bolt so providing they are kept lubricated they actually give a decent ride.

Having said that I'm putting on Group 4 Escort rose jointed links once I can afford them!