Quote:
Originally Posted by synergy
I know poly is a plastic... I was just making sure the guy who said you cant make spacers out of plastic knew I was talking about polyu which is a specific kind incase he didn't understand what type we were talking about.
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You mean
me.
Quote:
Originally Posted by synergy
And the fact that it "has play" does not mean its deforming. It simply means that on a very small scale it has give. Just like all metals do. Its just poly mounts have a little more give than metal mounts.
I don't see any reason why the spacers ive seen on 4x4 trucks couldnt be made by simply taking a disc of poly and drilling it. As long as you drill accurately so it isnt off center I don't think the load would be that great. You only torque wheels down to 80-90ftlbs. As long as it doesnt crack and shear off in pieces it should be ok.
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That's what "give" is -- deformation ("play" is space between parts, such as valve lash). Yes, all materials have a
modulus of elasticity, but it's absurd to suggest that since all materials deform, there must be no worthwhile difference.
A quick search shows that the hardest
polyurethane deforms 80 times more than aluminum (data
here and
here). Look at the deflection values for polyurethane in the link and you'll see that torquing wheels down will deform polyurethane significantly. Noticeable bulging and deflection happens when you tighten polyurethane sway bar end link bushings. This is why dedicated race cars use rod ends for sway bar links and solid pillow blocks and/or bearings for the frame mounts -- the deflection is significantly reduced when going to metals.
You do get this, whether you consciously realize it or not. After all, you replaced rubber with polyurethane in a number of locations in your drift car, but limited application of aluminum because of aluminum's
lack of deflection. Thus, you realize there are significant differences in deflection and deformation between rubber versus polyurethane and polyurethane versus aluminum. If you did not realize this, you would not have gone from rubber to polyurethane in your drift car or proposed the above items, right?