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View Full Version : Urethane or Rubber?



Duane
11-26-00, 02:11 PM
New to the list and new to Vettes. I'm restoring a '73 convertible and need to replace the suspension (among other things) and would like to get some opinions on the bushings.

I am primarily looking for a comfortable street ride, and would appreciate any other suspension advice or tips that anyone may have. Such as shocks, springs, and leaf spring (steel or fiberglass composite). Any leads on package deals would also be greatly appreciated.

This is my daily driver and keeping her 100% original is not a priority.

Thanks

Yoda
11-26-00, 02:40 PM
Duane,
First off Welcome to CorvetteNH :D

If you are serious about keeping your car original then the answer is rubber. I replaced all the rubber on my '81 with rubber. The new rubber made a big difference in the handling and ride. NeoPlastic bushings have come a long way since the '80's and don't squeek as bad is in the old days, and now you can get them in black. I prefer the rubber, keeps it stock and if you ever want to run an autocross it keeps you in the stock class.

Shocks: I recommend Gas shocks. I put Delco gas on mine, there are a myrid of mfr. to select from. I would suggest gas filled shocks, the adjustable ride type, Not the Old "air shocks", but the gas filled.

Rear Spring: You probably have a 7 leaf spring, unless there is something wrong with it I would not replace it, new rubber does wonders, but there are many vendors that sell rear springs, steel and the new carbon plastic composite type. I prefer the steel.

You need to get on a couple of mailing lists for parts and assy: I do not endorse any of these vendors, they are just a list for you to check out www.corvettecentral.com (http://www.corvettecentral.com) www.zip-corvette.com (http://www.zip-corvette.com) www.madirect.com (http://www.madirect.com) www.ecklers.com (http://www.ecklers.com) www.vettebrakes.com (http://www.vettebrakes.com)
There are lots more, these are just the books I have next to the computer.

We have years of experience and knowledge here in CorvetteNH, keep coming back, keep asking questions. ;)

Enjoy the experience and the ride, STW

BudD
http://www.corvetteforum.net/c3/budd/wavey.gif

Another good source for parts/vendors is the drop down menu at the top of the page. The INORMATION has vendors and phone numbers; the SHOPPING CENTER has useful information too. What The Heck, just spend a little time and Look around CorvetteNH there is LOTS of information that you will find useful.

[This message has been edited by Rare81 (edited 11-26-2000).]

[Edited by Rare81 on 01-28-2001 at 01:53 PM]

robert kirk
11-30-00, 05:40 PM
just put new urethane bushings on my 71. car handles great. for me this was the best choice. i dont race the car just drive and enjoy. staying stock or ori was not important to me so this seemed the best choice. made a world of diff. would do it again. no expert but hope this helps.71 454 4sp conv.

Yoda
01-28-01, 01:54 PM
Manny,

Here is the post I mentioned in the Saloon this morning ;)

BudD
:w

ssvett
01-28-01, 02:36 PM
I know this is an old post and BMT(Before my time) but I would like to add my 2 cents worth. I have installed urethane bushing on 2 cars. 1 a 70 convertable(CPE) Customer provided equipment. The bolts on the A frames came loose and one fell out. The 2nd one was a 72 convt again CPE, they caused the car to drive like a lumber wagon, and they too have worked loose. We will be changeing them back to rubber very soon. The rubber bushings in most cases has lasted 20 to 30 years. That's pretty good for $6.00 parts. And imagine what the first 20 or 30 years were like, espescially when you consider the next 20 or 30 years. These cars are now garaged and pampered, not in there first life, they were driven and abused. Now, if you were doing some serious road racing, then that would be a differant story.........Steve

Ms Kiss
01-28-01, 03:29 PM
Hello Duane,
I did the suspension upgrade on my 79. Polyurethane bushings. Unbelievable difference! Especially in rally racing. I changed to a composite rear spring, should of stayed with original steel......and the HD sway bars tightened everything up. I got a kit through Mid-America. Shocks are always a personal preference. I guess it depends on how sensitive your buns are.
Old threads are cool, shows members care.

[Edited by Ms Kiss on 01-28-2001 at 03:45 PM]

starz
02-02-01, 04:16 PM
hi:
starting in feb 1985 corvette fever ran a
many mounths long series. called the "vet
improvement program" it was written by john
greenwood and covered many things in the
first one feb 1985 he talked of bushings

he said
" page 34 i've experimented with solid versus
rubber a arm bushings in race competition and
the changes were so subtle that few professional
drivers could tell the difference."

he went on to mention things he knew to be
week points ..
idler arm
"if you gymkhana your vet may lose controling
ability quickly..... for street replace with
heavy duty... if race nouthing short of bearing
idler arm will suffice.

strut rods
he mentioned to check them
check the bushings i am replacing mine now.
(i have the strut rods with thouse ends
in them that look like a ball bearing with
a hole drilled in them. i am changing to the
ones with the plastic inserts as i have about
8 or 10 thou play in mine.

i find what he said of springs interesting
sep 1985
page 33
" the frount sticks better than the rear.
the balance you are looking for is a rear spring
rate 20-30% lighter than frount."

for shocks he said koni gas shocks.

it was a very interesting series of issue's as
readers signed up and each mounth you could read
there feed back on these changes and there
experience of making them.

hope this helps.

ksems
02-02-01, 04:28 PM
Okay , I have 2 cents worth as well:)

I replaced my rear spring bushings with polyurethane...
and although they work fine , they do squeak now and then when going over a bump.
It annoys me because at work I park in a parking garage with several speed bumps....every bump....squeek...no matter how slow I go.

I think when I refresh the whole suspension , I will be going with rubber.:D

Good Luck,
Kevin

GS796
02-02-01, 04:48 PM
Ok people, let me put this myth to rest. Polyurethane does not cause a rougher ride. Now lets think about this for a second.. when most people install new control arm bushings they typically install at the same time new shocks and or coil springs. Maybe, jusy maybe do you think that they could be relating the new found stiffness to the new shocks or coils ?? Now there are different grades of urethane also that can cause some harshness, that are typically installed in autocross or track cars, but these type of bushings are not typically available to the general public unless you know where to buy them. This all comes from years of manufacturing and selling this type of bushing as well as the "standard" poly bushing. The best way to describe the differance between rubber and poly is, take a pencil and hold it with your finget tips at one end, and then use your other hand's finger tips and hold the oppisite end of the pencil, then wiggle the the pencil using either hand. This would be what rubber bushings do. Now move one of your hands closer to the other hand say 3/4 of the length of the pencil, and then wiggle it again. Notice how it's now a bit more difficult to move the pencil ? this would be how poly reacts. With rubber bushings installed the car will more of a tendancy to "roll over" when cornering, poly reduces that deflection and makes the car a little more stable. If poly is installed correctly with the correct greese it will provide a squeekless ride for many years, I'm going on 10+
personally, and it will seldomly need replacing. Among the vendors that sell "poly" and I use this term loosly, because I can give you 10 differant names that all mean the same i.e. prothane, delalum, poly graphite etc.. we use and endorse Energy® brand bushings, for street and light autocross applications. We do offer a race quality hard poly for strict autocross and also metal for race only applications, but that a whole differant world. So dont be afraid of using poly, just be critcal of how or who is installing it, rubber is fine if thats your preferance.
We now return you to your normally sheduled channel :)

Dave
Guldstrand Motorsports
http://www.guldstrand.com