Garandman Posted December 1, 2006 Share Posted December 1, 2006 "sarcastic responses to cut someone down" != benefit to anyone here Wow, I could be a mod too... : This is the second time that I have seen lbGT getting cut down by a mod when he is contributing to conversation. Are you guys all good friends and I just can't tell thru the inter-ether? I would really like to know so I don't get angry when I see it. (I hate getting angry at computers, they don't bleed!) Perhaps in addition to Moderators we should have "Dampers" or "Shock Absorbers" to dampen the thread and bring it back towards the intended topic. I used to work in the R&D department of an automotive molder. We made rubber, plastic and urethane parts for OEM applications Ford, GM, and Chyrsler. I am not a polymer scientist but I did work for two PhD's and we had our own polymer chemist on staff. The answer is - it depends. Some urethane kits are similar durometer to the OEM rubber, and designed simply to be more durable. Others are sold with much higher durometer than stock to be more responsive at the price of ride comfort. And some race cars have those components machined out of acetal (one trade name is Delrin) or other hard plastics - instead of the brass machinings used previously. All these materials stand up well to the incredibly harsh environmental conditions of automotive use. Urethane parts are typically easier to make in low volume. BTW, Durometer testing is not very high tech. There's a little device that looks like a combination of a tread depth gage and air pressure gage. It has a spring and an "indentor" that measures how much the material is deformed. It's not as easy as you'd think. There are several durometer scales. They are usually described as "Shore" numbers, and there are two commonly encountered Shore scales - A for softer materials and D for harder ones. The device used to test for Shore hardness is called a Durometer. A google search will provide furlongs of facts to argue about this further..... Who Dares Wins スバル Link to comment Share on other sites More sharing options...
Wangspeed Posted December 1, 2006 Share Posted December 1, 2006 Rubber v polyurethane - It depends on the application. If the poly is harder, then you'll have more NVH to deal with, but it may improve handling. However, poly also will allow less axial movement, and may bind. Every Honda/Acura I ever drove on track with poly bushings was a nightmare compared to rubber or spherical bearings. But again, it depends on the nature of each specific bushing and application. Warren Link to comment Share on other sites More sharing options...
Deer Killer Posted December 1, 2006 Share Posted December 1, 2006 Ken, I know Merv already PM'ed you about this, but YOUR BUSHINGS ARE FINE! I know they are cracked... EVERYONE'S lower control arm bushings are cracked... While I don't like the looks of them either, SOA has said that cracks are normal and not a problem. If it makes you feel better then go ahead and get them changed, but it is not a safety issue. Uhhhh WHAT? Not a safety issue? Do you work for SOA or something? It was hard to drive the car at highway speeds, almost like there were 60mph crosswinds going back and forth.. All over the road... and that was with the bushing still in one piece, if I had let it go another couple thousand miles until it ripped apart completely... it would have been bad. Link to comment Share on other sites More sharing options...
Xenonk Posted December 1, 2006 Share Posted December 1, 2006 ^ im still on cracked bushings running around on the track, it's fine, there's a safety design in them even if they do crack all the way through. I think we discussed this before about the bushings dealing forces on a 2-axis system and not 3-axis. I already talked to Ken about this issue about rubber vs poly and how it really depends on the situation and application. So in that regards, I agree with Warren and VVG as well. Not every application in the car needs to be rubber nor every piece has to be poly.. it really depends on what it is needed.. some parts and pieces need to be rubber to have some give in it while others need to be stiffer which at some given point, why have poly when you get full metal? Then the next thing to think about is comparing metal vs poly vs rubber. Where does it end? We should all draw the line at what it the application is. Not be a turd, but since this thread is stirring up some dirt, I'll say this much: not everyone even knows if their car is falling apart and not everyone knows how to drive, just live with the happy medium that the car has wear and tear parts and that not every driver is a good one. Keefe Link to comment Share on other sites More sharing options...
Fast05 Posted December 1, 2006 Share Posted December 1, 2006 http://img39.photobucket.com/albums/v120/Snoopy0614/USA%20Drift%20Wreck/IMG_2401.jpg Link to comment Share on other sites More sharing options...
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