Real Fiero Tech

I have no problem greasing poly - I think UHMW is a little too stiff for street use atleast for control arm bushings

The Dark Side of Will wrote:I made UHMW rear bushings at the same time I made Delrin front bushings, and they're holding up just fine, after the Delrin bushings needed to be replaced.

Can you comment on the ride quality of UHMW vs. polyurethane vs. rubber?

UHMW is a significantly harsher ride than worn out rubber. I think that it results in greater reduction of ride quality than the 325ppi springs and Koni shocks. I've never used poly bushings on a Fiero, so I can't compare the two. The solid feel it gives the suspension is second to none.
Now if only I could eliminate the play in the rack and associated vibration in the steering wheel....

I have the same problem, have singled it down to a worn out rack bushing. Just need to get in there and replace the thing.

Don't forget that the pinion and rack wear. We're not dealing with transmission quality gears. The racks are pretty soft. The teeth wear and get mushroomed. Even with the pinion tension adjustment, there's still play in the unit, which allows the vibration that the UHMW bushings don't absorb to find it's way into the steering wheel.

What's a new rack cost these days? $400? It's starting to look worthwhile...

Have you checked the fiero store lately? I believe their reconditioned ones are $220, but you have to send in a core. I haven't heard anything about fiero store's rack & pinion so I don't know, but it's alot cheaper than a $450 replacement (what a local repair shop quoted on a new rack & pinion).

Since there are no new rack gears and no new pinion gears available, reconditioned R&P's have the same problem, or at least develop it shortly. I've tried.

My current idea is to talk to Sweet MFG about having a small run of custom racks and pinions made to drop the rate down to 2 turns lock to lock.

well if they do the small run and it's less than $450 per rack & pinion setup I'd really like to know

I will shout it from the hilltops to get as many people as possible onboard to get the price as low as possible.

At least you have a somewhat realistic expectation of what it might cost.

Phools on Fagland wouldn't pay more than $23.95 for it...

Kohburn wrote:I have no problem greasing poly

does poly have a better looking sister? :la:

no but she's got some stiff nipples on er

The Dark Side of Will wrote:Good suggestion. Guided research is much more productive than not knowing which way to go.

Originally posted by Will:
Worn out cradle bushings will cause the rear of the car to blip to the left when powershifting... if you don't have a stick, you obviously can't do this test.

...coming from someone who uses 'blip' as a technical term. And no one bothered to look at Gerald Stvorik's site. The sway bar bushings aren't one piece. Going back to Herb Adam's book that you referenced above the stiffer the end links, the more effective the sway bar. Herb sold sway bars with swivel links built into them and for a while Rodney Dickman sold conversions for 88's (I didn't ask him if he still did since I don't own an 88). Will, your pics help, but if more constructive exchanges can't be developed here, I doubt the Tech site will be around long.

notyourmomma wrote:

The Dark Side of Will wrote:Good suggestion. Guided research is much more productive than not knowing which way to go.

Originally posted by Will:
Worn out cradle bushings will cause the rear of the car to blip to the left when powershifting... if you don't have a stick, you obviously can't do this test.

...coming from someone who uses 'blip' as a technical term. And no one bothered to look at Gerald Stvorik's site. The sway bar bushings aren't one piece. Going back to Herb Adam's book that you referenced above the stiffer the end links, the more effective the sway bar. Herb sold sway bars with swivel links built into them and for a while Rodney Dickman sold conversions for 88's (I didn't ask him if he still did since I don't own an 88). Will, your pics help, but if more constructive exchanges can't be developed here, I doubt the Tech site will be around long.

What point are you trying to make?
Elsewhere in that post or one closeby I mentioned that since the individual in question was already looking at 8Shark's site, then he knew what bushings he ought to get for his car.

What do you think we should be expounding or elaborating on to make this section more constructive?

notyourmomma wrote: ...coming from someone who uses 'blip' as a technical term. And no one bothered to look at Gerald Stvorik's site. The sway bar bushings aren't one piece. Going back to Herb Adam's book that you referenced above the stiffer the end links, the more effective the sway bar. Herb sold sway bars with swivel links built into them and for a while Rodney Dickman sold conversions for 88's (I didn't ask him if he still did since I don't own an 88). Will, your pics help, but if more constructive exchanges can't be developed here, I doubt the Tech site will be around long.

was this post really worth bring the thread back from a 21 day nap?

Since you brought up the subject of bushings.....
Delrin is an engineering plastic, acetyl resin to be exact, and makes for excellent bearings. It will carry a high load. It has little give. Absorbs very little water. Delrin would make good bushings for a race car, but on the street.....

UHMW will have some give to it. It is much more dimentionally stable than Teflon and just about as slick. It's real stiff, also, as it, too, is an engineering plastic.

Nylon 6/6 is excelent for bearings and bushings. However, Nylon absorbs water and if machined too closely to the ID of the sleeve, it will bind.

MDS filled Nylon 6/6 - Read - moly -filled. Super wear resistant, self lubricating...but very stiff. This is the best of the nylons or engineering plastics.

Delrin AF - Teflon filled Delrin. About as slick as UHMW and much stronger.

There are a handful of other engineeing plastics, all with about the same properties. They are hard and stiff. Hit a bump and they don't give very much. Good for racing. Tough on the steet.

Polyurethane - an elastomer. It comes in many different hardness ranges, from as softy as natural rubber to about as stiff as UHMW. But it is elastic, that is it compresses and springs back. This allows for some shock absorption. I think that poly has taken a bad rap because it's been furnished in too many different durometers to make adequate comparisons.

Right now I run poly bushings in a Ryane Slalom front end and polys on a custom built rear a-arm arangement. It's about as stiff as I want to go.

I preffer polyurethane - but I should add that the OHHH so common problem of the bushing sleeves rusting to the through bolts.. non existent issue with my grease fittings the grease goes in flows around and through the bushing/sleeve and comes out around the bolt.

just add a little squirt of fresh grease to all the fittings with every oil change and the poly will last a long long time and never squeek

wcapman wrote:Since you brought up the subject of bushings.....
Delrin is an engineering plastic, acetyl resin to be exact, and makes for excellent bearings. It will carry a high load. It has little give. Absorbs very little water. Delrin would make good bushings for a race car, but on the street.....

UHMW will have some give to it. It is much more dimentionally stable than Teflon and just about as slick. It's real stiff, also, as it, too, is an engineering plastic.

Nylon 6/6 is excelent for bearings and bushings. However, Nylon absorbs water and if machined too closely to the ID of the sleeve, it will bind.

MDS filled Nylon 6/6 - Read - moly -filled. Super wear resistant, self lubricating...but very stiff. This is the best of the nylons or engineering plastics.

Delrin AF - Teflon filled Delrin. About as slick as UHMW and much stronger.

There are a handful of other engineeing plastics, all with about the same properties. They are hard and stiff. Hit a bump and they don't give very much. Good for racing. Tough on the steet.

Polyurethane - an elastomer. It comes in many different hardness ranges, from as softy as natural rubber to about as stiff as UHMW. But it is elastic, that is it compresses and springs back. This allows for some shock absorption. I think that poly has taken a bad rap because it's been furnished in too many different durometers to make adequate comparisons.

Right now I run poly bushings in a Ryane Slalom front end and polys on a custom built rear a-arm arangement. It's about as stiff as I want to go.

Well fancy meeting you here! Welcome!

How does the lubricity of polyurethane compare to that of UHMW? I have UHMW front suspension bushings, and without the spring or shock in place, the friction in the bushings barely supports the weight of the control arms... nice and slippery. I've heard of poly bushings with so much friction that the weight of the car isn't enough to settle the suspension.
That's why I shy away from poly bushings.

on a tip(i'm not recommending it), I used anti-seize instead of the supplied grease with my poly and it was able to settle fine.

with my poly before greasing it i could move the control arms easily by hand.