Jump to content

Control arm bushings


19Cutlass94

Recommended Posts

Does anybody have measurements for these? ES has a listing on poly control arm bushings but no measurements on the website. Im hoping to be able to get poly bushings from them if they have the correct size.

Link to comment
Share on other sites

Too bad no one makes w-body LCA's with QA1 rod ends instead of poly. Tubular or boxed control arms with poly bushings force the LCA mounting brackets on the chassis to bend. Another result is forcing the lower control arms to twist.

Link to comment
Share on other sites

DOHCfeind on 60degreev6 is working with a company on getting tubular lower control arms made up complete with Poly Bushings. I think he sad he price point was going to be $200+. When he gets the ball going I think I'm going to be jumping on the bandwagon, should go great with my coil overs.

 

Jamie

Link to comment
Share on other sites

why are you guys stuck with poly bushings for this? yeah using poly bushings are fine for body mounts, sway bar mounts, motor mounts, tranny mounts, but thats it. engineers designed the suspension components to have deflection because it's required in most locations. poly mounts basically reduce deflection to nothing. when you reduce the suspension components travel, that piece will bind up.

Link to comment
Share on other sites

Then why do all the major aftermarket suspension companies use poly? Another popular choice for bushings is Delrin, which is even more dense than urethane if I'm not mistaken. If you go to a performance suspension based forum, pro-touring.com for example, most of the people there are using Poly. So what are they all missing? Keep in mind those of us that are looking for poly bushings are the few people that want to push our w-bodys right to the edge of their performance ability. And even fewer, like me, want to be able to push it farther and get a way with it.

I don't see how using poly bushings will cause parts to bind up. Rubber bushings have a memory to them. For example your control arm bushings, with the car jacked up and struts removed, if you move the control arm up or down it will return to the starting point. Poly does not do this, allowing the suspension components to move more freely.

Maybe I just don't understand what your trying to say, thats entirely possible, I'm exhausted....

 

Jamie

Link to comment
Share on other sites

Some suspension assemblies are a simple hinge--the parts will move up 'n' down freely.

 

I can't think of any reason that the front control arms of a "W" body would need to deflect as they travel. Seems like a simple hinge joint to me. I don't understand how firmer bushings would bend the control arm mounts. I'm thinking Poly bushings would be fine in that application.

 

 

By comparison, some suspension assemblies are designed in such a way that the control arms must have bushing deflection (or arm deflection) as they go thorough the range of motion (suspension travel.) For example, an older solid-axle, coil-sprung assembly--such as a GM "A" body from '64 to end of RWD production--has the upper arms angled so as to not be parallel with the lower arms. Those kind of suspensions require some deflection (have binding issues.)

 

Bushing deflection--especially on the front end--is also called "compliance" and it reduces harshness. It also reduces steering precision--it's just like having a flexible frame that cannot positively locate the control arm. Poly bushings reduce deflection/compliance and as a result they "can" add harshness along with better handling. Personally, I've not noticed harshness in the vehicles I've converted to poly bushings.

Link to comment
Share on other sites

why are you guys stuck with poly bushings for this? yeah using poly bushings are fine for body mounts, sway bar mounts, motor mounts, tranny mounts, but thats it. engineers designed the suspension components to have deflection because it's required in most locations. poly mounts basically reduce deflection to nothing. when you reduce the suspension components travel, that piece will bind up.

 

Maybe I dont understand what youre saying, but the only "deflection" that the lower control arm needs is rotational about the axis of the lower control arm bolts. I dont see how poly bushings would hinder this rotation any more than rubber would. You could make the bushings out of stainless steel if you wanted and that would probably help the rotation even more, but as its been said before, more of the vibration of the tire would be transmitted to the subframe.

Link to comment
Share on other sites

Now.. back on topic... Im doing alot of reading about that deflections issue kinda thing. And on the control arms, I dont see where it would make a differnce. But Im still reading about such things. And besides, if they do make such a bad deal, then why do all the aftermarket companies that make tubular a-arms come with poly bushings?

Link to comment
Share on other sites

Damn, I wish I would have caught this thread earlier.

 

Repeat offenders, again. Warning's and 3 day vacations will start to be handed out if it's kept up.

 

Otherwise, keep it on topic.

Link to comment
Share on other sites

I think it has been established that poly mounts will, as Schurkey said, reduce compliance. I'm glad he brought that term up. When we build our race car, one goal is to reduce compliance. We do this by eliminating any flexure that we don't want at the suspension points. At every place where one suspension component bolts to the frame or another suspension component, we have stainless steel bushings that are spot on. The tolerances of the bushing have to be very small and the fit of them borders on an interference fit. The less compliance you have, the less shifting goes on when you change your car's acceleration due to a steering input.

 

I've stated my point with deflection. My best guess is that the poster of that comment meant that poly would be "stickier" than the stock rubber, meaning that it would take more force to rotate the control arms out of their natural resting position. If thats what he meant, i dont see this being a real issue, but i dont have experience with poly.

 

With all that said, all that is needed are dimensions of the current bushing seats (as stated in the FIRST POST) and see if energy suspension makes these. You could probably get on the phone with the measurements and ask them if they have anything like that around. If it doesn't, it wouldn't hurt to ask them to make that size, or get a group buy going. I'd be interested. Anyone with a disposable income to buy a j/y control arm and bolts. Or just someone with some free time to go to the jy and take good measurements. I havent been able to get to the j/y in a few weeks now.

Link to comment
Share on other sites

yeah as stated above all I need are measurements. If ES doesnt have anything close they will need to be made. I would imagine that this will not be cheap. But I will as about a group buy and any discounts that may apply.

Link to comment
Share on other sites

Poly can possibly be machined, if proper care was taken. but its not reccommended. I imagine it might be easier to make control arm bushings than something else. What you would have to do is to make the poly cold before you start machining and keep it cold, possibly with keyboard cleaner or something like that and you would have to support it at the end. You would have to work fast and cool it down often to keep it hard and machinable. This is sort of a sleep induced half baked idea right now, but it just might work. I know you can pick up rods of poly from ebay and probably mcmaster with various durometer ratings. Higher durometer would give less compliance and a little bit easier machining. Or derlin could be used, im not sure about the machining practices with this, but they might be easier. If you wanna try, you might even be able to get a few cartridge bearings in there, but that would require very high precision, which I doubt is equipped on any of our cars from the factory.

Link to comment
Share on other sites

I agree that SOME suspension components NEED to have deflection (namely the rear setup on these cars), but the front control arms are NOT one of them (as mentioned, they just pivot up and down).

 

So............if *I* was doing a W-Body suspension, I WOULD do poly for the front control arms, both sway bar

bushings and endlinks and poly for the steering rack bushings (also help steering precision a touch.

 

But NOT for the rear lateral links............the trailing arms maybe, but NOT the lateral links.

 

The reason???

 

The lateral links HAVE to deflect a little through their travel due to the trailing arms forcing them backward slightly as they go through their arc............so yeah, a little deflection IS needed on the REAR.

 

 

 

 

BTW........if you DID do poly EVERYTHING out back, you'd go into a corner, lean hard over, and the rear would bind..........whoop-de-do..........

 

NOT.

 

A bound up suspension equals an infinite spring rate (just like hitting the bump stops).........infinite spring rate on the rear equals a VERY snap-happy rear end..........as is scary "oh shit!" oversteer.

 

So yeah. While I agree that FRONT control arm bushings are ok with the W-Body suspension design, *I* would not go tooooo far with poly goodies out back.

Link to comment
Share on other sites

poly can be machined, I have had poly machined before. i have pics, let me see if I can find them.

 

Yeah, I was about to say, just about all round poly bushings are machined to proper spec after being molded. The guys that have done the ploy bushing for the early dogbones will have noticed the machining marks on them.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...