Hot Rod Forum banner

Is Polyur. Really Better Than Rubber??

1K views 14 replies 11 participants last post by  OneMoreTime 
#1 ·
Hey everyone.
I own a mostly stock 1975 Camaro with inline 6 engine, daily driver. I am in need of overall steering/ suspension upgrades- new front end kit, new shocks (all 4), leaf springs bushings, and probably leaf springs, too.
I have been excited about getting an all new front end kit from either Moog or PST, with the polyurethane bushings that last forever and supposedly reduce roll transferrence compared with rubber. These kits are around $500 (including centerlink), but I see simple stock replacement rubber kits for under $200, like this one: http://cgi.ebay.com/ebaymotors/ws/e...736&viewitem=&sspagename=ADME:B:WNAFP:US:1123

My question is: Is there really a difference?? There probably is, but how much?? Are the tie rods and non bushing parts better as well? Just want to be sure it's worth it... thanks!! Any other comments on my suspension upgrades are welcome. Thanks again
 

Attachments

See less See more
1
#2 ·
up front

What are you going to be doing with your Camaro?
If its only a DD with that inline 6, then the stock stuff would be plenty fine. I can't see the extra cost.
If you plan to work it hard in the autocross or something (or if you just want to be able to brag about an upgrade), then spend the extra.
I think the extra moola could be better spent in a number of ways.
good luck.
 
#3 ·
If you want the car to handle better than when it was new then the polyurethane is a good move. The actual hard parts in most kits(ball joints, tie rod ends, center link) are the same, only the bushings are different. We did a '74 Z28 with poly and it drives like a slot car, very responsive and solid in a corner.

The kit you linked doesn't have the eight a-arm bushings nor the two sway bar pillowblock bushings in the kit, just the hard wear parts. No bump stops either.
 
#5 ·
reply

thanks for the responses-
I am hoping (debating with myself :evil: ) to put in a 383, a 700 r4, and a limited slip rear end; give it good power while as smooth and drivable as possible. These cars handle and brake pretty good. Has anyone tried or know about a limited slip, maybe from Eaton? Or a Flaming River close ratio steering box conversion?
 
#6 ·
I used an polyurethane kit to rebuild my front end on my 1984 Chevy C-10 pickup with only 80,000 miles and the truck steers and handles great. An big improvement over the rubber bushings. Ride is slightly stiffer. I bought my kit from an name brand componet company. I would be careful about E-Bay also on the quality, you usually get what you pay for. As far as the rear end Eaton Limited Slip is the best, E-Bay is full of G.M. Locker which I have been told are inferior, and weak for an engine that has any kind of H.P.
 
#7 ·
Many of the GM limited slip axles are the Gov-Loc, which is not a good choice for most performance cars.

The gov-loc uses an internal mechanical mechanism to sense when the rpm is about 200 rpm difference between the two wheels, and then it engages and locks. If you spin the wheels up slowly it will engage slowly and probably work fine. If you spin the wheels up quickly (like a burnout) it will engage very abruptly and may self-destruct internally from the sudden engagement.

Bruce
 
#8 ·
Go Poly

If I were you I'd go with the poly. I did my 74 firebird and it made a great difference in handling and that's what the car needs to do is handle better. Just remember that grease is a main factor when installing these. They will squeak if you don't grease them properly. Have a good one!!
 
#9 ·
Poly v Rubber

On a driver, I'd go with the stock rubber bushings.

I restore/modify Jags and if you upgrade to a full poly set, it degrades the ride and can stress other components (lower A-arms for instance) and for a street car, the handling difference is just not worth it. In addition, the harsher ride will develop lots of other squeaks and rattles in the car over time. I'd go stock.

One other alternative I've used is stock rubber except the anti-sway bar link ends and mount. That won't effect the ride to any great degree but will make the car more responsive into corners with less roll.

Just my $0.02 worth.
 
#10 ·
For a daily driver, rubber in the control arms and poly everywhere else. Replace the subframe mounts with poly also. Big difference.

The biggest bushing bang for your buck in bushings are polyurethane anti-roll bar frame and link bushings.

For your 6 cylinder car, see if you can find larger factory anti-roll bars. A V8 car will likely have a larger dia front bar, and a Z-28 will have a rear one you can add to your car. Those larger bars with the stock rate springs will help a lot. If you are upgrading the drivetrain, you may want to consider stiffer springs also.

Andy
 
#13 ·
InsideMan said:
I never heard of using rubber bushings for the control arms, and poly for the rest. Is this to decease the stress on the arms while shifting weight?
Essentially what I am talking about is using OEM rubber bushings in the inner control arms to reduce vibration to the passenger compartment. They will also provide a long service life with no maintenance. The only other bushings in the front end are on the anti-roll bar frame mounts and end links. Installing urethane bushings there will improve the performace of the anti-roll bar without transmitting much vibration. Install all new hard parts (idler arm, tie-rods and ball joints) and you are done. Then mess with the springs and shocks.

Andy
 
#14 ·
I replaced the front control arms with rubber and the rear with urethane on my 1970 Skylark. I welded and boxed the rears also. I did not want a harsh front end and I hate squeaks. The car will understeer as it was designed just not as much with big block springs and a hefty anti sway bar. As far as high speed tight cornering get a Lotus. LOL :cool:
 
#15 ·
aosborn said:
Essentially what I am talking about is using OEM rubber bushings in the inner control arms to reduce vibration to the passenger compartment. They will also provide a long service life with no maintenance. The only other bushings in the front end are on the anti-roll bar frame mounts and end links. Installing urethane bushings there will improve the performace of the anti-roll bar without transmitting much vibration. Install all new hard parts (idler arm, tie-rods and ball joints) and you are done. Then mess with the springs and shocks.

Andy
If itis mine I also fit some stouter sway bars to control body roll and install new springs and shocks on a car that is now 30 years old as the springs will wear out and sag..when done the car is just so much nicer to drive..look at shock valving as well..

Sam
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top