87-96 Rear Axle Suspension plastic inserts

Want some new struts? What brand springs to buy? How much camber to run? What brake pads? What's the best setup for your situation....
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KFLO 93 GT
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Re: 87-96 Rear Axle Suspension plastic inserts

Post by KFLO 93 GT »

I'm with SGR.

As little as I drive my car, and for what I do with it when I do drive it - I may be interested.

More info is needed to satisfy my curious mind. :)


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by ErichZ26 »

SuzukiGhostRider wrote:Plastic? That sounds rather scary for rear end inserts. Some sort of high grade plastic or something? Cool idea, but go more in depth. I'm curious on the specs. Quality material, tensile strength, etc. What kind of load it will stand up to or abuse?
It is very high quality plastic. It is machinable and used in at my fathers shop where he uses this for making products for the food industry. He makes cookie/cracker rolls/cutters. This stuff has incredible tensile strength.

Its Kosher, 100% virgin Ultra-high-molecular-weight polyethylene aka UHMW or Polyoxymethylene aka POM aka and has a Delrin trade name.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by SuzukiGhostRider »

Ok, but again, a cookie cutter sustains a LOT less strain, stress, weight and power than a rear end on a car. What , if any , field testing has been done on these inserts to insure they will stand up to the strain and stress of everyday driving, let alone hardcore track driving?


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Re: 87-96 Rear Axle Suspension plastic inserts

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SuzukiGhostRider wrote:Ok, but again, a cookie cutter sustains a LOT less strain, stress, weight and power than a rear end on a car. What , if any , field testing has been done on these inserts to insure they will stand up to the strain and stress of everyday driving, let alone hardcore track driving?
Not really, I could show you bronze that gets worn down from dough. This stuff is a hell of a lot more durable than the stock butyl rubber in your existing bushings...not to mention softer Polyurethane used by Energy or window weld you see people squirting into their engine mounts. If anything, its probably overkill.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by ErichZ26 »

Here is a datasheet. BTW, i also have access to HDPE..its listed on this material sheet.

http://www.boedeker.com/polye_p.htm


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by weba »

These are massive upgrade over the stock options in what comes to rigidity.
SuzukiGhostRider wrote:everyday driving
Knowing what kind of taste most people in US seem to have to car suspensions, Please keep in mind that stuff like this is not meant for daily drivers. I am swapping NOS FE7 bushings to (daily) black car. These specials are going into the white one. And I can provide road\abuse testing as soon they get here.

Performance is always a trade off from comfort. If your car's main purpose is grocery getting, you do Not want to have stiff ass suspension. But if you can separate the daily tasks to other car, and the built up car is for spirited driving, racing...... You know. Very little is what you can mix these 2 completely different aspects IMO. =@

Hell, I am actually planning to get rid of my custom solid engine mounts on the black car (since they do not work as planned, but add insane amounts of harshness, vibration and specially noise.) I might actually even get rid off the polys in control arms because of the same reason and horrible roads over here.. Going back to comfort on daily driving, guess I'm getting old? Next thing I will be adding sound killer :lol:

Remember the illustration I've used before?

Performance |----o---------------------| Comfort
I think these ^ would be about here in our platform. Going Aluminum bushings would be far left, and stock FE1 bushings would be right.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by SuzukiGhostRider »

I actually wasn't referring to , or caring about, ride quality and comfort. Rather SAFETY. I would think these inserts will snap under strain. I just think they should be road tested before touted an "upgrade" or "better than stock".


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by ErichZ26 »

SGR: Is your concern that these are too firm and that the bolts that hold this in will shear off? I am not sure if you know this but i actually went to college for mechanical engineering and passed my strength of material class. It would be a pleasure to calculate this. Keep in mind there are a lot of unequal forces here, and some things are a bit more dense.

Liljon: when you made the plastic inserts for the steering rack did you get bombarded like this? The material difference is the same and that is for steering component that could vibrate loose if not properly secured.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by weba »

SuzukiGhostRider wrote: I would think these inserts will snap under strain.
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Seriously. :roll:


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by 3X00-Modified »

ErichZ26 wrote:SGR: Is your concern that these are too firm and that the bolts that hold this in will shear off? I am not sure if you know this but i actually went to college for mechanical engineering and passed my strength of material class. It would be a pleasure to calculate this. Keep in mind there are a lot of unequal forces here, and some things are a bit more dense.

Liljon: when you made the plastic inserts for the steering rack did you get bombarded like this? The material difference is the same and that is for steering component that could vibrate loose if not properly secured.
No actually no one bothered me about it... they just wanted some.

I recently pulled mine that I had in the pink car due to them being just a little undersized so I had too much play in the rack. I think the delrin ones I did are still in the red car and those were fine. If I were to have them made again I would have them made as a firm press in item to ensure they fit tight and give no slop.

I never heard any complaints from anyone who bought them either.

Glad I'm not the only one who can't make sense of SGR lately.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by Barry »

Yeah I had a technical post written up about how it is unreasonable for plastic "snap" while pressed into a metal sleeve but my browser killed it.

Only people who push the limit of their cars on a daily basis will gain anything from these. I am really interested in seeing how they work.

We need some give in these bushings for the axle to flex and be semi independent. With these bushings, more of the flex will be forced into the actual trailing arms and the torsion bar between them.

I support you making these. We really need to try it before we can decide weather it is a good design or not. I trust that weba will put these through their paces and give us a accurate report. I would love a more oversteer happy setup.

I am also in school for mechanical engineering.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by Barry »

I also dont think aluminum would be necessary and will wear too quickly. UHMW is VERY dense and is pretty slick. With some dry graphite lube on the bolts I think these can last for a very long time without getting sloppy. A pressed in sleeve will further extend their life by spreading the load.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by SuzukiGhostRider »

Why am I the bad guy all of a sudden? I was thinking of buying some and am voicing legitimate , imo, concerns. I mean, to me plastic just sounds ..... weak?

I guess I'll have to be the "retard" here as Weba says. What do I know...

I can see why steering rack inserts would get a lot less of a hard line of questioning. The rack itself takes very little physical pounding by driving the car hard. The suspension and steering take that beating. Thus , my concerns.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by ErichZ26 »

SuzukiGhostRider wrote:Why am I the bad guy all of a sudden? I was thinking of buying some and am voicing legitimate , imo, concerns. I mean, to me plastic just sounds ..... weak?

I guess I'll have to be the "retard" here as Weba says. What do I know...

How about I send you a sample. I could convince my dad to make you a nice 6" long UHMW shaft to handle and to test its durability. You can pound it..throw it around a little...bite into it. I guarantee its the strongest plastic you have ever played with.


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Re: 87-96 Rear Axle Suspension plastic inserts

Post by Barry »

Just go on mcmaster and buy a small peice. Its good stuff

In my last internship I was working as a bio-pharm manufacturing engineer. The most 3 common plastics I used were LDPE HDPE and UHMW. Its all great stuff, UHMW being the strongest.

I made some parts out of it on a mill and its easy and quick to machine.


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