Poly or Rubber
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 751
Likes: 0
From: Lufkin Texas
Originally Posted by Restorod '79
Rubber will restore your car to it's original drive new from the factory.
Poly will give every component a stiffer feel, more suited for aggressive driving or racing. How do you plan to use your car?
Poly will give every component a stiffer feel, more suited for aggressive driving or racing. How do you plan to use your car?
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 751
Likes: 0
From: Lufkin Texas
Originally Posted by jdmick
Poly will enhance road feel but won't do much for improved handling. I've heard people complain about their rough riding poly bushings so I rebuilt mine with rubber and am glad I did.
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
I replaced mine with poly about 7 years ago. You can do them yourself without removing the original outer sleeves and you don't need a press to reinstall the new bushings, so you don't have to depend on anybody else to help with the job. There is also the potential for distortion of the control arms when pressing in new bushing sleeves-not a problem with urethane as long as you leave the existing outer sleeves in place. If you put a good smear of the (supplied) silicone grease on the new bushings per instructions, they don't make noise for thousands of miles, and when they finally do start squeaking a little shot of silicone spray quiets them right down. They're generally a little more expensive than rubber ones, but not that much, and the difference in road feel/harshness is barely noticeable, especially with modern radial tires which are immeasurably better than the old billiard-ball bias-ply tires that your C3 originally came with. Unless you've just gotta have NCRS correctness they're hard to beat IMHO.
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 751
Likes: 0
From: Lufkin Texas
Originally Posted by SIXFOOTER
For a performance feel go with Poly, along with good shocks and springs your car will turn like its on rails
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Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Either one will last a long itme, mine had rubber and was 26 yrs old, had a couple bad ones.
I did the poly conversion on my 77 when I got it, that car would do a 90* turn 45 mph and stay in the lane, passengers didn't like it much tho, LOL
I did the poly conversion on my 77 when I got it, that car would do a 90* turn 45 mph and stay in the lane, passengers didn't like it much tho, LOL
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 751
Likes: 0
From: Lufkin Texas
Originally Posted by SIXFOOTER
Either one will last a long itme, mine had rubber and was 26 yrs old, had a couple bad ones.
I did the poly conversion on my 77 when I got it, that car would do a 90* turn 45 mph and stay in the lane, passengers didn't like it much tho, LOL
I did the poly conversion on my 77 when I got it, that car would do a 90* turn 45 mph and stay in the lane, passengers didn't like it much tho, LOL
Advanced
Joined: Apr 2006
Posts: 71
Likes: 0
From: Norwalk Ohio
Rubber every time...
I vote for rubber... But what do I know, I only design suspensions and suspension bushings for a living... 
Seriously, though... We've done heads up testing of polyurethane and natural rubber bushings... Rubber always wins.
When I rebuilt the suspension on my 1980 Trans Am, i used rubber. When I rebush my 1972 Corvette, I'll use rubber.
The suspension on the C3 Corvette was designed to use rubber bushings. The company I work for designed the original bushings these cars. The suspension was tuned to use bushings with a certain spring rate, and I'll guarantee that if you replace a 65 durometer mechanically bonded bushing with a preset amount of wall compression with a 90 plus durometer chunk of polyurethane with zero wall compression, you won't get the spring rate that the suspension was tuned to use.
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Mwieczorek
Seriously, though... We've done heads up testing of polyurethane and natural rubber bushings... Rubber always wins.
When I rebuilt the suspension on my 1980 Trans Am, i used rubber. When I rebush my 1972 Corvette, I'll use rubber.
The suspension on the C3 Corvette was designed to use rubber bushings. The company I work for designed the original bushings these cars. The suspension was tuned to use bushings with a certain spring rate, and I'll guarantee that if you replace a 65 durometer mechanically bonded bushing with a preset amount of wall compression with a 90 plus durometer chunk of polyurethane with zero wall compression, you won't get the spring rate that the suspension was tuned to use.
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Mwieczorek
Thread Starter
Burning Brakes
Joined: Aug 2005
Posts: 751
Likes: 0
From: Lufkin Texas
Originally Posted by MWieczorek
I vote for rubber... But what do I know, I only design suspensions and suspension bushings for a living...
Seriously, though... We've done heads up testing of polyurethane and natural rubber bushings... Rubber always wins.
When I rebuilt the suspension on my 1980 Trans Am, i used rubber. When I rebush my 1972 Corvette, I'll use rubber.
The suspension on the C3 Corvette was designed to use rubber bushings. The company I work for designed the original bushings these cars. The suspension was tuned to use bushings with a certain spring rate, and I'll guarantee that if you replace a 65 durometer mechanically bonded bushing with a preset amount of wall compression with a 90 plus durometer chunk of polyurethane with zero wall compression, you won't get the spring rate that the suspension was tuned to use.
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Mwieczorek
Seriously, though... We've done heads up testing of polyurethane and natural rubber bushings... Rubber always wins.
When I rebuilt the suspension on my 1980 Trans Am, i used rubber. When I rebush my 1972 Corvette, I'll use rubber.
The suspension on the C3 Corvette was designed to use rubber bushings. The company I work for designed the original bushings these cars. The suspension was tuned to use bushings with a certain spring rate, and I'll guarantee that if you replace a 65 durometer mechanically bonded bushing with a preset amount of wall compression with a 90 plus durometer chunk of polyurethane with zero wall compression, you won't get the spring rate that the suspension was tuned to use.
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Mwieczorek
Race Director
Joined: Dec 2000
Posts: 10,896
Likes: 2
From: CO
Originally Posted by MWieczorek
The suspension on the C3 Corvette was designed to use rubber bushings. The company I work for designed the original bushings these cars. The suspension was tuned to use bushings with a certain spring rate, and I'll guarantee that if you replace a 65 durometer mechanically bonded bushing with a preset amount of wall compression with a 90 plus durometer chunk of polyurethane with zero wall compression, you won't get the spring rate that the suspension was tuned to use.
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Rubber is expensive, polyurethane is cheap. If poly gave satisfactory results, the OEM's (auto manufacturers) would switch to polyurethane bushings in a heartbeat. Trouble is, poly doesn't give satisfactory results, which is why they're still using rubber!
Poly lasts longer doesn't it? Also Poly kits are more expensive than rubber right? At least when I got mine they were.
If my suspension isn't stock, doesn't that change the argument? I have 550# springs and bilsteins. I always heard that poly doesn't flex as much as rubber so you get less deflection with poly. In fact my friend makes nylon bushings and swears by them.
I guess I would have to disagree. I dont really have any comparison data because my rubber bushings were totally shot. So I only know what the suspension feels like with new poly.
Last edited by flood; Oct 27, 2006 at 06:41 PM.
Le Mans Master
Joined: Jun 2002
Posts: 8,339
Likes: 24
From: I can walk to MA
Rubber rebounds, where poly deforms under extreme pressure.
I think rubber will even outlast poly bushings ....
but I choose poly for the easy of installation.
Rubber bushings must be torqued down with the full weight
on the suspension. If you have a plastic radiator shroud, you
will need to remove the radiator to do this properly (with rubber).
Since the poly bushings rotate like a hinge, they can be torqued on the
bench and installed in a heartbeat. Perfect for a one-day rebuild.
You can do rubber in a day - but it will be a long day.
I think rubber will even outlast poly bushings ....
but I choose poly for the easy of installation.
Rubber bushings must be torqued down with the full weight
on the suspension. If you have a plastic radiator shroud, you
will need to remove the radiator to do this properly (with rubber).
Since the poly bushings rotate like a hinge, they can be torqued on the
bench and installed in a heartbeat. Perfect for a one-day rebuild.
You can do rubber in a day - but it will be a long day.
Melting Slicks
Joined: Aug 2006
Posts: 3,429
Likes: 20
From: Kingston Ontario
squeaks
Remember to either get polygraphite or use a lot of the goop they give you with the kit, they will drive you crazy with squeaks if you don't. I put them on my 81 when I had it and it didn't lean one bit in the corners. Good tires would really compliment the bushings.
