Bushings: poly-carbonate vs. poly-graphite

cowtown · 06-29-2004, 08:11 AM

I'm thinking about replacing the (probably original) suspension bushings on my '75 911S.

I've settled on using OEM rubber or monoball for the rear trailing arms, but I'm up in the air about which material to use for:

-Rear springplates (Neatrix rubber, poly-carbonate, or poly-graphite)

-A-arms (poly-carbonate or poly-graphite).

What exactly is the difference between poly-carbonate and poly-graphite?

Thanks,
Colin

widebody911 · widebody911's Garage

I have the Neatrix spring plate bushings, and I'm not that happy with them. This winter I'm going to upgrade, most likely to the Poly-bronze elephant bushings.

I have the Weltmeister 'race' bushings in the front, and I like them, but I'll probably upgrade them as well.

RoninLB · 06-29-2004, 08:30 AM

some guys don't like transmitted street harmonics.. some guys don't mind. Calif roads are relatively smooth.

KobaltBlau · 06-29-2004, 08:38 AM

Colin, are PolyBronze out of the budget?

cowtown · 06-29-2004, 08:41 AM

Thanks for the replies,

I just can't justify the price of the polybronze on this car. I know they're the best, but that's the bottom line.

I'm trying to figure out what's the next-best - polygraphite, polycarbonate, or neatrix?

BGCarrera32 · 06-29-2004, 08:50 AM

I did soft poly, which a year ago anyway was available from Pelican. Its somewhere between the factory rubber and all out rigid. The fit was obnoxiously tight and I had to bore the i.d. out on the lathe before the bushing would slip on. I also cut in a grease channel and added a zerk for lubrication. There is an article in this months (I think it was this months) copy of Excellence where they did something similar with the hard poly bushings on a 911. All in all they have worked well, but for the farting around and labor hours you're probably money ahead with the Elephant poly bronze setup.

KobaltBlau · 06-29-2004, 08:50 AM

OK. That's completely fair. I'm not sure what the next best is.

RoninLB · 06-29-2004, 09:15 AM

Quote:

Originally posted by KobaltBlau
OK. That's completely fair. I'm not sure what the next best is.

yep.. Elephant Man's bushing are a class act. I've had the Welt bushings on a street 911 since before Elephant Racing was born.

cowtown · 06-29-2004, 01:13 PM

Bump - already off the front page

Anyone know the difference between polygraphite and polycarbonate bushings? Wear? Noise? Durability?

KobaltBlau · 06-29-2004, 01:21 PM

I probably just don't know much about bushings, but Lexan is a polycarbonate. Those "nalgene bottles" in the harder plastic are made out of lexan. This seems like a pretty rigid (even crackable) material for bushings. Delrin is more suitable for rigid bushings...

Where are you seeing polycarbonate bushings?

cowtown · 06-29-2004, 01:34 PM

Quote:

Originally posted by KobaltBlau
Where are you seeing polycarbonate bushings?

I was just kind of surfing around Pelican and saw these:

(1974-89) Front Suspension A-arm Rear Bushing, Poly-Carbonate (sold per each, 2 req. per car), 911/911 Turbo/912E (1974-89) [Photo]
PB-012R $13.75

Front Suspension A-arm Front Bushing, Poly-Carbonate (sold per each, 2 req. per car), 911/911 Turbo/912E (1974-89) [Photo]
PB-012F $13.75

Front Suspension A-arm Bushing Kit (Set of 4), Poly-Carbonate, 911/911 Turbo/912E

KobaltBlau · 06-29-2004, 01:38 PM

Hmm, maybe a pelican staffer can clarify. Betcha they're really polyurethane.

Chuck Moreland · 06-29-2004, 02:04 PM

Not a staffer, but the listing is a typo. Those are polyurethane bushings.

Nobody makes a polycarbonate bushing. Polycarbonate would be a poor choice for bushing material. Fitment would be even more problematic than the current crop of polyurethane bushings.

Polygraphite is made from graphite impregnated polyurethane. The graphite is an effort to reduce the squeaking problems so common with polyurethane bushings. It may provide some marginal improvement, but can still squeak.

Az911 · 06-29-2004, 02:20 PM

Don't be cheap when it comes to suspension. You are willing to spend the extra few dollers for the rear momoballs do the same for the front and go polybronze

cowtown · 02:28 PM

Ah-ha! Thanks for clarifying, guys.

AZ, I know where you're coming from, but $38.95 vs $237.50 is over my threshhold...I'm trying to be realistic about the car's value, use (90% street, 10% DE), and bang-for-the-buck.

I know many others see it differently and I greatly respect Elephant's products.

Colin

KobaltBlau · 06-29-2004, 02:42 PM

Quote:

Originally posted by Chuck Moreland
Not a staffer, but the listing is a typo. Those are polyurethane bushings.

Nobody makes a polycarbonate bushing. Polycarbonate would be a poor choice for bushing material. Fitment would be even more problematic than the current crop of polyurethane bushings.

Thanks Chuck, that's what I was thinking.

dickster · 06-29-2004, 11:27 PM

colin,

i agree, if cost is an issue why bother with monoballs?

i went with neatrix in the rear - i wish i had done ploybronze, but if cost is an issue i would stick with neatrix.

the fronts are a problem. the poly's are a pain to fit properly - i opted for polybronze.

btw-polybronze are fairly new on the scene (?) so while they are very well made, durability remains an unknown - unless anyone can share any info that confirms their longevity.