shamby

I plan on getting a front end rebuild kit this weekend at the Corvette Expo in Knoxville. Could someone tell me why Poly bushings is much better then the rubber ones. Plus, would you use Poly or rubber for the body mounts.

ddecart

Polyurethane bushings are stiffer than rubber bushings. They will decrease compliance in your front (or rear) end. The counterpoint is that they will also increase ride harshness since they don't have as much of a cushioning effect as rubber.

Personally, ride is low on my list and I'd go with poly. Although they do have a tendency to squeak.

Dave

verskel

Yeah, the poly doesn't 'give' as much as rubber does which keeps the tires 'glued' to the pavement.
In 'road race' cars they take it one step further - brass bushings ! :D
You can ask REDVETRCR on this one - brass makes your teeth rattle... :lol:

Anyways - a lot of guys will talk about squeeks, creaks, etc. - but I have poly on mine & the only time it creaks is when I pull into a driveway.

Rubber also 'rots' and can crack when stuff (fluids) spill on it. I'd say poly is the way to go. Now are you planning on Poly-urethane or Poly-graphite ? :chevy

shamby

Now are you planning on Poly-urethane or Poly-graphite ? What? I Have know idea. I probably don't need the graphite.
Thanks for all the info

Gator81

It's hard to quantify the difference with words. I would urge you to find a car similar to yours with poly installed and drive it.

I changed mine from worn out original rubber to new poly a few months ago, and I am quite happy with it. Again, it's hard to quantify. I also did springs, shocks, steering linkage, ball joints, every suspension bushing, rear bearings (actually, complete trailing arms), switched to VB&P Smart Struts, and added a rear sway bar. So the before/after comparison cannot isolate an individual component and tell you how it feels. All I can do is describe the overall effect of all the changes together.

The car handles much, much flatter in corners, which is wonderful. It feels incredibly tight and responsive. It feels like it will go precisely where I point it at any speed I'm willing to put into it.

It is noisier. My poly bushings do not squeak. They're graphite-impregnated, and were installed with gobs of Teflon-Silicone lube. The noise is road noise, transmitted through the poly bushings to the cockpit. Even on the smoothest road, you can "feel" the texture of the road surface in the seat of your pants. You feel every expansion joint on a concrete road, you feel the texture of the gravel on an asphalt road. That's not necessarily bad or good, it's just not the same as rubber. Rubber would absorb most of that noise. There is also more of the creaking and groaning that old Corvettes do, because the suspension is so much stiffer that there is significantly more load transfer from front to rear, side to side, as you go over bumps and especially driveway dips.

As for body mounts, I haven't changed those yet. Based on my experience with the poly suspension bushings, I'd probably go with poly, but I'm not sure. Depends on how much more road noise would come through. I feel certain the poly will last longer. Some of those old rubber bushings were probably in need of replacement 10 years ago.

Good luck! :seeya

shamby

I'll go with the Poly. I plan on getting the full front end kit from VB. I also plan on getting the 360lbs fiberglass mone spring from them. Do I need to replace the busining in the backend also. Does someone offer a kit that provides all the busings needed for the front and back, including trailing arms. I am in the middles of a frame off, so I figure since it is accessable now, I should go ahead and do it.


[Modified by shamby, 11:23 AM 4/12/2002]

Flareside

Just to be different ;) I've installed poly on other cars, not my Vette, and didn't really like it. It adds a harshness to the ride that I can do without. I didn't really like the "scrunching" sounds when I went up my driveway either. I just rebuild my front suspension with all new rubber bushings.

Gator81

Sure, in a frame-off, do it all. No question.

I'm not aware of a single kit that has every piece of rubber/poly in it, but VB&P can put a few kits together that will cover it. I believe that they have every piece available. I got all of my stuff from them, except the trailing arms, which I got from Van Steel. The Van Steel trailing arms have an exclusive poly bushing which they manufacture themselves. Their competition can offer you either a stock GM rubber bushing, or a 2-piece poly bushing insert. The Van Steel poly bushing is made by taking brand new GM bushing shells and pouring molten polyurethane into them, thereby truly recreating the GM bushing in 1-piece poly instead of rubber. It's a superior system to the 2-piece bushing insert.

Just call VB&P and tell 'em what you want. You're not the first guy to call them up and say "I need it all!". Good luck! :seeya

shamby

The Rubber is much cheaper, plus this is not my everyday driving car. I am trying to justify the extra expense for the poly.
Decisions, Decisions, Decisions..

427V8

If you want to feel a dime when you run over it AND be able to tell if it's heads ot tails, go with poly, if you just want to make a nice car and want it to ride nice go with rubber.

I have Poly everything except rear camber rods, which are Hiem joints.
and body mounts, which are Aluminum ( stock equipment in '69 )

LATNC3

how about NYLON bushing???

Rod :cool:

Tom73

It depends upon how you are going to use the car. Is it a race car? Road racing or autocrossing? If so go with Poly, less deflection will give better suspension control when on the edge at the track. Street car, stay with rubber.

You will see alot of posts where someone installed polly bushings on their car and they say it did wonders for the car. But, don't forget, they are more then likely comparing the new poly bushings to old worn out rubber bushing. Sure it made a big difference. But in those cases anything would have made a big improvement.

tom...

ZD75blue

last for almost forever... good enough for me, i'll upgrade next time around :jester


[Modified by ZD75blue, 8:53 AM 4/13/2002]