neilb

I was wondering If anyone here has made their own rear control arms? I'm thinking I could do it cheaper and just as well as aftermarket arms. I have a set of energy suspension poly bushings that I will use. I'm just not sure what thickness of metal I should be using, and should I go tubular or square? Any pics and tips on what you have done would be awesome.

I started today by removing the passenger side control arm in order to get some measurements. I think I'll draw up some actual size plans for easier fabrication.

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iTrader: (14)

most arms are made from anywhere from 1.25 to 1.75 DOM with a wall of .095 to .120.

Square is easier to work with sometimes, but round looks better.

Personally, i would do round if you are making them from scratch. Adjustable wont hurt either.

FueledSoul

iTrader: (18)

Im not a fan of the poly/poly ends for many reasons.
honesty if your going to run poly bushings in the control arms id just box the stock ones and be done with it.

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iTrader: (14)

it would work better if you didnt box the stock arms and use the poly. that way the arms will still flex a bit and help with the binding issues

FueledSoul

iTrader: (18)

I fully agree with you. But he is planing on making a set from steel and running poly/poly if that's what his plans are it would much cheaper and easy to box the stock ones. I personlly would never run poly poly ends on the lcas

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iTrader: (14)

that is true

neilb

Whats wrong with poly? I thought that was the best of the best when it came to bushing materials? I thought about boxing the stock control arms, however, I'm running 29"Hoosier slicks. I need stiffer control arms plus some extra clearance for the bigger tire. My thought was to offset the centre beam on the bushing ends towards the middle of the car to gain some clearance.

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iTrader: (14)

not anymore, poly is stiff, and works fine in application with no twisting forces, like the front control arms, but even there, delrin is the way to go now.

as for the rear control arms, they have to articulate up and down and side to side a little. The stock rubber bushings are soft and give enough deflection trhat you dont have to worry too much about bind, poly however, has much less give, so it binds.

in all reality, you will probably not notice a difference unless you really push the car for better handling.

in a perfect world, both ends of the rear LCA's should be a bearing of some kind, either a steel rod end, or a delrin raced rod end type setup, ect. Thats more for all out performance though.

//<86TA>\\

iTrader: (14)

offsetting the arms will be fine, but you need a pretty wide tire before you need them

83 Crossfire TA

iTrader: (2)

It really depends on the application... yes, if you twist poly bushings in their pockets and they're dry they can bind and in a RR or autox situation this will cause snap oversteer (in a turn they will tighten, tighten more a then suddenly let go and the back end of the car will try to swap ends), but you can prevent that by keeping them lubricated (some are drilled/tapped for zirks, and some have flutes cut in them to channel grease, I've cut them by hand in those that don't).

the fact is that you'll NEVER see a problem drag racing or on the street.

Most bushings are a compromise anyway. Durlin is great for a bushing that doesn't get twisted but won't work at all for an LCA, and solid bearings/bushings are harsh and don't tend to last well when exposed to everyday use/weather.

Really, for a slower than 10second car that is not a competitive autocrosser or road racer, box the stock arms and us good stock rubber bushings. If you feel you need something more, put the poly bushings in and make sure that they're greased...

88camaroluvr

lilnebel made me a custom set of adjustable LCAs. I have yet to install them tho.

Duts87ss

iTrader: (10)

Greasing the poly bushing will only allow them to rotate on their axis easier. It will not help prevent snap oversteer in any way unless the bushing happens to be binding (from friction) about their axis of rotation.

I agree, that with the thirdgen rear, snap oversteer will probably never happen on the street with boxed and poly trailing arms. The converging 4-link in my Monte is a different story. I have experience snap oversteer while not driving overly agressive, but with a slight bank in the turn. I've since switched to Eddy uppers and will soon go to some custom lowers I had made by suicidedoors.com (spherical joints in both ends). I run factory replacement rubber bushings in the rearend for the uppers.