Polygraphite or OEM Rubber?

[David Wagle]

I plan on having the front end rebuilt in my Duster. Do any of you have experience with the Polygraphite front end kits and if so, what are your opinions? Good, bad, or indifferent? Thanks.

[ehostler]

Definately go polygraphite. It is much better than rubber.

The two best places are JustSuspension and PST.

[mOlson]

Is there a defference between polyurathane and polygraphite??

Ed, do you have any experience with switching from fresh rubber bushings to polyurathane on the same car? Just wondering how much of a difference in added vibration/harshness there is. I understand the benefits of additional longeveity of polyurathane and less bushing deflection but do you think the difference in ride is an acceptable trade-off? I have no experience riding in a car with polyurathane bushings myself.

My experience: the bushings in my Charger are ~10yrs old and all of them show signs of either splitting or dry rot. I am planning on using rubber replacements simply from my impression from other people of poly having a harsher ride.

Without a doubt, new rubber bushings absolutely transforms the car; definitely worth the effort. Although I do feel confident in guessing that fresh polyurathane bushings must feel better than clapped out rubber bushes any day.

Any other's have opinions one way or the other??

[ehostler]

My bad, only PST has Polygraphite bushings.

Polygraphite is a graphite-impregnated polyurethane. It gives all of the advantages of polyurethane while maintaing the flexability of rubber.

From the PST website:

Stock Rubber Bushings "deflect" under load, affecting suspension geometry and handling characteristics.

Years ago performance driving enthusiasts and racers replaced the factory rubber front suspension bushings with solid aluminum or steel bushings. This produced "flatter" cornering in competition but, the metal bushings soon proved to be too stiff, causing premature suspension failure or excessive wear. Then came polyurethane. It was much firmer than stock rubber bushings yet flexible enough to reduce severe pavement to chassis shock. A definite improvement, polyurethane soon began appearing on street driven vehicles. However, since polyurethane must rotate with suspension travel (unlike twisting, elastic action of rubber) new friction points were created which again caused premature wear along with annoying squeaks.

After years of development, PST introduced POLYGRAPHITE®, a graphite-impregnated high performance bushing designed for street, strip or track driven cars. Now all cars can have the road handling characteristics of polyurethane bushings with virtually no deflection and the self-lubricating qualities of graphite.

Our exclusive High Performance POLYGRAPHITE® Front End Kits are designed for enthusiasts who demand more handling performance from their cars than mere transportation. For people who appreciate responsive handling, increased control and the road holding characteristics of true performance automobiles there is only one choice- POLYGRAPHITE® a PST exclusi

[ehostler]

As far as how firm the ride is, I myself would rather have a firm ride, than the boat ride that rubber offers.

When I go to rebuild the suspension on my cars, they will get the Polygraphite bushing, HD sway bars, and HD torsion bars. The ride may be a little firm, but my boat of a B-body will at least be able to corner like never before, instead of giving a hard lean with tire squel.

[mOlson]

Thanks for clearing that up; the polygraphite sounds like a really good compromise.

As far as the floating boat feel, I am sure you know that is mostly shock absorber related. My Charger with a small block, rubber bushings, replacement R/T front and rear springs, KYB dampers and 235/70 14 tires handles much to my liking. Very smooth ride and solid, consistant handling. The bushings really start to make a difference under higher suspension loading (eg from stickier tires) and corners with less than smooth road surfaces.

My daily driver is a suby wagon with Japan spec sport suspension and 45 series tires. The car holds a turn like you would not beleive but any mid-corner bumps throws off the suspension geometry like mad and the car skips off line. I am fairly certain this is from the stock rubber strut tops not being designed to take that sort of loading. My point is when you make a change from stock, consider what other components are affected and may need upgrading as well. Like the trashed front wheel bearings on my suby....

I hope this is helpful for you Dave. I just may be going polygraphite when I put my order in this fall.

[David Wagle]

All the input is great, I sure appreciate it. I ordered my leaf springs from Year One and my Torsion Bars from Mopar Performance today. I am going to order my front end kit from PST but I need to contact the guy I got the car from. They ask me if it has dual or single piston calipers. I know the brakes are all new but I'm not sure about the calipers. Also, what do you guys think of swaybars? It doesn't have one now and it will be mainly a work car and weekend cruiser.

[mOlson]

I assume you mean it does not have a rear swaybar correct? Driving without a front swaybar is....um....

Swaybars are used to change the balance of the car and do this mainly by reducing traction at that end. Find a big parking lot and unhook your front bar. Trail the brakes into a fast sweeping corner and you will quickly find yourself going forwards backwards. The front tires will have all kinds of added traction and the unweighted rears (from braking) will slide out on you. Most cars just have a front bar from the factory which biases the car towards understeer (front end plow) which is safer for the average driver.

I really do not see a reason to add a rear bar for the use you mention. Stock Mopar suspension designs are simply top notch. Just add some good shocks and have a competent tech align the car and you are good to go.

[David Wagle]

I don't want to sound like an idiot here, but I obviously don't know where to look for th front sway bar. The guy I talked to at PST said it should go from wheel to wheel and run underneath the radiator. The only thick bar I see is the one that runs underneath the oil pan. Your help is appreciated.

[ehostler]

It connect from the endlink assembley (which is connected to the lower A-arm), then runs across the front of the K-member (attached by two brackets with bushings), and connects to the opposing side endlink.

Here is what it looks like:

[David Wagle]

Just wanted to keep you guys that have helped me updated. I took my car to the shop today and it doesn't have a sway bar in the front or rear. It's not an original 340 car so I don't think it came with one. I was under the impression swaybars came standard on the high performance models.

[Marc]

Just a thought....
We put a PST polygraphite front end kit in a local guy's Charger.
He came back two weeks later, asking how much it would cost to replace the new stuff with rubber.
The ride was a LITTLE harsh, but it was the SQUEAKING that was his concern. He tried polygraphite lubricants, racer's tricks, etc... but still wasn't happy.

I'm not saying some people haven't been completely happy with polygraphite, but it is one instance I KNOW that it's disappointed.

Just thought I'd let you know....????

[David Wagle]

Thanks Marc. Those stories are helpful in making my decision. It's good to hear from people who have firsthand knowledge in some of this stuff. This whole thread has been really informative and the experiences and input from everybody is great! I'll be sure and let everybody know how it goes. I am going to try and have the work done around the middle of October. My wife and I plan on taking the kids to Disneyland, I won't be using the car then anyway.

[George G. Leverette]

Poly this Poly..... this is a good advertising gimmick promising improved ride and handling, which are not mutually compatiable.
A good OEM replacement will give about 90% of drivers satisfaction in ride handling and longevity, I have seen 30 year old Mopars in the yards with what appears to be detorirating rubber and the interiors of the bushings are still good. MOOG Improved is a little firmer than OEM and should be considered. I have the Urethane stuff on all of my cars front and rear, along with the .92 torsion bars, frame connectors, KYB shocks, sway bar and 11\16 tie rods with 15x7" wheels and 60 series tires. firm feel steering and 11.87 disc up front and 10x 2 1\2" drums out back. Like the engine every thing works together to get the desired results. Urethane bushings that are black in color made by Energy Suspension are impregnated with graphite and sold through most vendors including Mopar Performance. Get the components that fit your driving style and frequency of use, remember the magazines get advertising dollars to sell the vendors products, never seen an article that stated something was bad or substandard .

[David Wagle]

Just wanted to keep you guys in the loop on what I'm doing. I ordered an OEM front end kit from PST today along with a swaybar. As I said before all the opinions, experiences etc were very helpful in making my decision. My springs won't be here until late Oct which works out good since that is when I plan on having the work done. My Torsion bars should be in around tuesday I think. I can't wait to get the work done and see what a difference it will make. I will definitely post and let you guys know how it goes. I will more than likely be posting alot of questions etc. It's been years since I've had an old Mopar. I had a 74 Duster back in 89-90. It was alot of fun but I had it about a year then got "new car fever". I also had a 76 Volare for about a year, that car was a story by itself. Suffice it to say I will never buy another car from a pawn shop again. Live and learn I guess.

[George G. Leverette]

Sorry to hear that you ordered from PST the torsion bars are available from Mopar for less than half the price and you can determine the spring rate, the aftermarket bars could have the same rate you are using now. Do you still have an auto hobby shop where you can buy at discount from local vendors? Also look on the net for a Mopar car club in your area, they usually buy from the dealers at cost +10%.

[David Wagle]

The only things I ordered from PST are the front end kit and swaybar. The Torsion bars I did order from Mopar Performance and the leaf springs thru Year One which in turn orders them from the Eaton Company in Detroit. We do have an Auto Hobby shop here that I plan on using. I am looking for a local Car club or Mopar specific club. If anybody knows about either one let me know.