The original article at least gave this credit:

Resource
Energy Suspension, 1131 Via Callejon, San Clemente, CA 92673, 949/361-3935, 888/913-6374, www.energysuspension.com

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Gee- what is it that Energy Suspension sells?

 

I went poly on the suspension bushings but rubber on the body mounts. Don't want my teeth to chatter too much.

 

What are they?
I'd think that some of the bushing could benefit from the pros of poly.

 

I have poly bushings all over my car and wouldn't even consider changing back.

motor mounts,
trans mount,
rear end,
rear tie rods,
front suspension,
sway bars,
control arms,
replacing body mounts soon.

They deteriorate at a much slower rate than rubber, and are oil resistant!

But do some research of your own.

 

This is what I'm considering after reading all the posts.
I already purchased rubber body mounts, and I think the rear diff. snubber bushing should be rubber. But It also make sense that suspension parts could benefit from quality poly bushings.Then balanced with GOOD shocks and tires.
Thanks everyone.

 

Have both and I'll take Poly any day.

As as for as OEM A/C vs Vintage Air, the new technology is the way to go hands down.

 

In fact it is pretty simple.

Poly bushing work on the parts rotating. Poly is a sticky plastic, tending to stick to the sleeves and such, producing squeeking.

The shafts and A-arms are not made to exact tolerances (ask me how i know...). To make a bushing that relies solely on rotation work, the alignment of the bushings/shafts must be nearly perfect. If not the shaft will edge ride in the bushing creating excessive wear and causing squeeks.

Rubber allows for a lot more error in the alignment and thus ease in production. Plus it is cheap to produce and doesn't require much maintenance.

From a performance point of view i always though of poly's as a bad solution to the problem. Some kind of solid would be a good solution, but means you would need to get everything aligned properly, meaning a lot of work and requiring more maintenance.

I tried getting perfectly machined shafts and such, but to expensive. Going back to rubber as soon as i get my parts and forget about it.

 

My wife had a '79 C-3, bought it new and kept if for 19 years. At one point, around '90-'91, I went through it, and replaced all the bushings in the suspension, the body cushions, the ball joints shocks and springs.

I went with all poly bushings to sharpen up the handling a bit. The car had the OE sized tires on it, 225/70/15, which have a LOT of sidewall height, so I found no deteroriation in ride quality, as the tires soaked it up.

 

Belgian brought up some very valid points above that are rarely considered.

Two others:

1) many bushing locations are required to flex in all three planes simultaneously as the suspension moves through it's normal arc, the best example being front trailing arm bushings. Rubber is well adapted to this, poly is not. This introduces the possibility of binding or the need to reduce the the rigidity of the poly to compensate, which doubly backfires- see point 2

2) conventional bushing design specifically introduces torsion into the bushing material to vary compressibility/compliance as the suspension moves. This is achieved by bonding the material to the inner and outer shells, then positively locating the shells into final position when assembling the car. This is why the suspension must be at normal ride height whne torquing the assembly bolts and nuts. The effect is a calculated amount of shock absorption when the suspension is in the neutral position (reducing vibration, chatter etc.) but reduced compliance on a logarithmic scale as the suspension moves towards either limit. The compliance of the twisted rubber at it's design limit is equal to or less than poly, but without the teeth rattling while at normal ride height.

Poly bushings do not operate in the same manner at all- the material does not have the ability to be put into torsion giving it the desired variable compliance and as such is not bound to the suspension or chassis. Essentially, it's at 'full hardness' all the time. Eliminating vibration isolation opportunities by using poly body mounts, motor mounts or rear crossmember/diff mounts makes little sense to me.

What's left? Front anti roll bar link end bushings. No harm there I guess other than it introduces reaction from the bar at a faster rate than stock. No idea if anyone would notice or that the accelerated transition is a good thing.

Aside from that, sure knock yourself out. Poly wanna cracker?

 

I 100% agree poly isn't best suited to "3D" locations such as TA's and camber struts, and that poly isn't perfect. That said, complaince isn't your friend when it comes to maintaining dynamic suspension geometry*, and it depends on one's priorities as to what compromises may make sense.

Are poly bushings the best at anything? Not in particular, but they happen to fall right into the big gray area between ride quality and cornering capability (as do big bar soft spring (BBSS) setups IMCO), and swimming in that bowl of soup is just where many an owner wishes to be. Yes, rubber bushings and such may be great for their intended purposes. However, it shouldn't be assumed in the discussion that we all share those same purposes.

The point is, this isn't always a black & white issue with a one-size-fits-all answer, and I'd hesitate on taking anyone's side who believes it is.



*Yes, I've seen on rare occasion where gradual loading of anti-roll bar(s) can actually be desired, but that's not a geometry issue.

 

Sounds like I am the luckiest poly user on this forum, no squeeks, smoother ride, bolts are nice an tight, used hand tools for installation and most of the bushings were cheaper then original rubber. Also i'm running poly bushings on 2 cars, 79 and 80.

 

Yup -very true, both points of view need to be aired.

 

I know what i'm talking about and can tell you from first hand experience that the tolerances on the arms (even the VBP offset uppers) are not good to the extend that the solid bushings i tried to mount wouldn't even go on withour freezing the shaft solid. And I have the pictures to show what I'm talking about.

If you take a good look at a set of poly's the first thing you will notice how much play the bushing has in the shell and how much play there is between the sleeve and the shaft. This is all done to negate the effect of misalignment in the arms. Poly's by nature need to be considered as a solid bushing with practically no flex in them, relying soly on rotation.

BUT you can get lucky, I talked to guys that got solids on without a problem. It's one of those instances in which a poly would probably work without any squeeks or other associated problems.

To each his own but I'm tossing them out.

 

OK, I've installed 5 complete sets of poly A-Arm bushings (40 bushings), and have yet to see any of them that have any excess play ANYWHERE. To my experience, the poly bushings are a tight fit in the shells, the steel bushings are a snug fit inside the poly bushings, and the steel bushings are a reasonably snug, rotating fit on the a-arm shafts or bolts.


Just my $0.02 worth.....

 

If you take a good look at a set of poly's the first thing you will notice how much play the bushing has in the shell and how much play there is between the sleeve and the shaft. This is all done to negate the effect of misalignment in the arms. Poly's by nature need to be considered as a solid bushing with practically no flex in them, relying soly on rotation.

Maybe you had the wrong bushings? My bushings fit nice and snug, then I tapped the sleeve in with a hammer. Even used the VBP offset control arms.

 

If you look at the way the poly's are supposed to work, there is simply no way that this bushing can be a snug fit. They are supposed to rotate.
If you wiggle the diverse components in their housing and on the shaft, you will notice the movement.

 

If you like original (old school) stick with the rubber. If you want to modernize get poly. Grease them and they should never squeek.

All the talk about rotation with poly just makes me think, what the rubber must be going through with the same rotational forces. Rubber tears and rips, poly does not but can crack. Poly glides, rubber sticks and pills.

As far as engineering from 40 years being good by today's standards (using original rubber)......well, I guess I can only hope all the new Corvette guys think the same way, as I want to trade them my high performance originally engineered iron 350 and iron heads for their aluminum LS motor and aluminum heads. New times, new materials, new ideas, better outcomes=progress.

 

rubber is my opinion unless you race only

 

I also have poly bushings all over my car and wouldn't even consider changing back. That would be like going back to 15" wheels and tires.

 

By this it's obvious you don't understand how a conventional bushing operates.

Oh well, that's what the poly-pushers count on anyway.