raptere

So I currently I have Lakewood square tube rear LCAs with poly bushings. I have been doing autox this season, and have noticing the rear of the car not moving as it should on hard turning, and I suspect this is from the stiff poly/poly bushings.

My thought is this, what if you took out the bushings, and drilled an oversized hole about a third of the way down the ID bore of the bushing from the outside flanged end, so that the inside steel sleeve only contacts the bushing for the inner 2/3 of each bushing? This removed area would be where the greatest forces were previously, and now those forces would be redirected closer to the rotational axis, so the the remaining poly should flex more in twisting. Hopefully this would not result in too mush negative effect and flex in straight line acceleration.

Thoughts? Anyone ever heard of doing anything like this? If I were to try it I would maybe only do it on the rear two bushings first, then if I felt like I needed more do it on the fronts later.

raptere

I have a spare set of panhard rod poly bushings I was going to try experimenting on. Not sure if they are the same size as the LCA bushings, but are at least designed similarly. Problem is the ID is about 3/4 inch, so to drill them oversized I'd need a 7/8" or 13/16" bit, which I unfortunately do not have on hand...

My thought was something like this, but of course with a larger sized bit...

QwkTrip

iTrader: (22)

That might be a standard hole size where you can install different style bushings from Founders, UMI, Global West, ect...

Next level up from that is to cut off the end of your control arm and weld in a threaded insert and install a quality spherical rod end. Only need to do this on the axle side. It requires more maintenance though because it's more vulnerable to corrosion and dirt and such.

raptere

That would be a great solution if the bushing tube was a standardized size and I could simply replace one on each side. Anyway done this or know what the standard aftermarket bushing dimensions are?

I actually may be working on some custom proprietary LCAs in the near future, so at this point t I'm just looking for a temporary improvement solution... I do autocross the car about once a month, but I street drive the car also, to work, cruises on nice days, so full steel is not a good solution for me.

QwkTrip

iTrader: (22)

I have a fair weather car too. Been using spherical rod end on axle side for 6 years no problem and haven't needed to replace anything yet. I inspect, clean, and grease once a year. Even high-quality teflon lined rod ends are not expensive to replace. And the control arm length is adjustable (since the rod end threads in) so you can equalize arm length and square the axle to the chassis. And I'm not stuck with just spherical rod ends, I could thread in any kind of bushing I want, just need it mounted to a threaded rod. The adjustable arm length also gives me more flexibility with height adjustable control arm brackets.

Put your money into some well made arms with threaded end at the axle and then choose whatever style bushing you want. You might end up buying different bushings as you experiment with things, but you'll never have to buy another set of arms again. I think mine are chromoly round tube (out of production Kenny Brown).

TTOP350

iTrader: (8)

Best to sell off the poly stuff and use Rod ends

91banditt2

iTrader: (1)

For better articulation you better off with factory rubber than polyurethane the best option would be some sort of rod end type. From a Preformance handling point of view poly is really only beneficial in a couple places like sway bars and front control arm bushings and maybe even the body side of the panhard rod because some of its travel is up and down, the rear end side really needs more articulation than what poly can offer.

http://www.frrax.com/rrforum/index.php?showtopic=5255

Kfactor239

I used to race IMCA Stock Cars on dirt ovals. The frame and suspension they use is a gbody 4 link rear suspension. I had to use factory upper and lower arms but could use either stock rubber or poly bushings. I found the poly bushings tended to cause things to bind up and have less articulation. I went to a chassis school by one of the national champions from Iowa and he suggested not only using factory rubber but he also said he never tightened the bolts on the arms very much at all just enough that a washer wouldn't spin he said factory torque is great in a crash or hundreds of thousands of miles but if you want articulation you want as much movement as you can out of the joint as possible. Just a thought.

McLovin1181

I've been saying this for years.
poly suspension parts are crap 9 times out of 10.
poly simply doesn't give enough.
companies make the Poly durometer insanely hard for no damn reason, hard=binding.
The 1le LCA Bushings are a star shape for that very reason.
Even my brothers 240 Volvo has the same type of rubber bushings to avoid axle binding.

You can probably drill a few small holes to make the poly more compliant.
Or just bite the bullet and go Rod-RoD LCA.
The ride quality/Noise is slightly worse than poly.

BBU.COM

Since you have an extra set of the bushing, to soften them drill holes around the bushings edge, this will soften it, detrimental over time of course but this will give you more compliance and possibly the answer your looking for

RJ IROC

Why not save time and money with these:


I've had these on my car for 5-6 years with excellent results. The spherical poly bushing works well for getting rid of bind when going to a tubular arm. I used the supplied grease when I installed them new, and they have yet to show any signs of squeaking.

91banditt2

iTrader: (1)

"Our Poly-Joint bushing combination incorporates a very hard inner polyurethane ball which is surrounded by soft outer socket cups"
What are the outer socket cups made of? If they're a "softer" poly they still wont allow for full articulation like a rubber or a rod end. If they are poly then it's defeating the purpose, it's just poly bushings with extra steps. This is a good idea but only if the outer cups are rubber.

raptere

I am in complete agreement that articulation of the LCA's is critical for a free moving and well handling rear end. I can feel the need for it as I have been getting started in AutoX. I bought these LCA's 15 years ago when I knew nothing... I think it may have gotten lost in the discussion, but I am looking for a temporary solution to allow more articulation to my LCA's, trying to keep the costs to a minimum. I have a much better solution in the pipeline, but it may be a few of months before it becomes available to me.

So far I like two ideas:

This is my favorite solution so far and it's free and easy. I can start with an array of smaller holes, make them larger as necessary. I can also experiment with putting holes at the bushings just at one end vs both ends. Anyone have input on the size and number of holes, or whether it would be best at one end or both? I also wonder how much life this will take out of the bushing, I would hope it would still hold up a few months, maybe a season or two?

Camaro Firebird Lower Control Arm (foundersperformance.com)

This is my second best option. It does seem like a very inexpensive solution, but I still feel stupid buying a whole new set of arms for just a few months. If I could get just the bushings and could confirm they would fit my current arms, that may be a different story depending on the price, thought the price for the whole pair of arms at $92 is not terrible to digest... Can anyone confirm the OD and effective with of these bushings, or the mating tube so I can find out if they fit?

QwkTrip

iTrader: (22)

I would just grease 'em up good as a temporary solution.

91banditt2

iTrader: (1)

You could call Founders and they may give up that info, or they may not, wouldn't hurt to try
As for how many and how big the distance between the ID and OD is going to dictate that, start with holes at 12, 3, 6 and 9 o'clock then use your best judgment on how big and how many more, start small and work your way up, a large drill bits gonna tear them up, go to big or to many and they will fail.

raptere

Just got an email response from Founders, they do not sell the bushings separately...

Guess holey poly bushings it is!

QwkTrip

iTrader: (22)

Predictable outcome via e-mail. You're asking to buy something without a customer part number. Those kind of conversations need to happen over the phone where you can ask questions, plea, bargain, push back.

I've approached Founders before to buy a subcomponent. It's possible depending what it is, you just need to push back (in a nice way). Done the same with UMI and Detroit Speed and it was a much easier conversation and they had the parts in inventory on-site.

91banditt2

iTrader: (1)

Did you get them drilled out?

raptere

Not yet. I'll report back when I do. I have an autox Sunday and I have to get my front sway bar bushings figured out before that, factory rubbers are falling apart, but initial set i got were wrong for my 36mm bar, got a set of the blue moog ones yesterday, so fingers crossed those go in ok...

I hope to take a stab at this bushing experiment next week, while I'm also doing my rear brakes.

DynoDave43

iTrader: (11)

I like the drilled hole idea the best. An option would be to drill holes the size of a common hardware store bolt or allthread (if you can access smooth round stock, even better). These can be inserted into the holes to firm them up again if you went too far. But that's probably over-thinking what is meant to be a temporary fix.

BBU.COM

That is exactly what filling the holes would do. Long story short is a retired GM engineer that was in the development of the CTS-V suspension said this is how they found the stiffness they needed. They started with regular CTS bushing on the car and would drive nails into them to stiffen them, once they found the balance between ride comfort and control they were seeking the bushings were tested to find that hardness or durometer and the new bushings for the CTS-V were born.

DynoDave43

iTrader: (11)

Cool story!

I actually was introduced to the idea from the MOPAR side of the world. In '73 ( I think ), as the world was moving from muscle cars to personal luxury cars, they added large rubber bushings to the front cradle where it attached to the body (like a full frame car would have a rubber body mount), and in the rear the front leaf spring eye bushing went from round to oval. The oval bushing had a large round hole in the middle for the through-bolt, and two smaller ones either side of the large hole for who knows what reason. To firm up the oval bushing, you could fill those smaller holes. Something similar was done much later with Neon front engine mounts. They had voids in them to soften them up, and on the street or drag racing they would fail. Filling the voids stiffened them and helped them last longer. MOPAR Performance even sold a kit for doing it, IIRC.

raptere

Tried drilling out my sample peice. Started with 8 - 1/8" holes. I only drilled 5/8" deep from the outside, not through, so the greasing functionality will still work.

Just squeezing it by hand it seems like it may be a little more compliant... holes seem really small though, think I may go up one size more before first test, or should I not?


First set of 1/8" holes, again dont drill through or all your grease will come out...

Drew up this little thing in cad so i could use it as a template, then center punched each hole before moving to the drill press.

BBU.COM

I`d guess if I were doing it, I`d mount them in a control arm with the bolt sleeve and that whole trailing arm assembly in a vise and with a longer bolt or something that fits inside the sleeve - manually torque the bushing using leverage...like a science experiment, stock bushing set in one end of the arm for control and the modded one in the other to test the new variable (size of holes vs compliance)

raptere

I got started tonight modifying the actual bushings. It turns out the LCA bushings at least in my Lakewood arms, are not the same dimensions as the extra ones I had for my panhard rod. The ID is the same but all other dims are all slightly larger. I'll have to post all the actual dimensions in another post.


I still used my experimental piece as a template. I drilled through it into the actual LCA bushing.


For now I only didn't the rear bushings on the one side. I did go up one size to 9/64" in 8 places equally spaced. I went about 3/4 of the way into the bushing from the outside to keep the grease in place.



I'm a little worried because the portion of the bushing exposed to the elements is starting to get a little crumbly, but the central part seems better... hopefully these hold up...

I'd say, even if this works, it's enough effort that maybe it would have been worth it to just buy something instead of modifying what I have... We'll see...

raptere

Here are the dimensions of the bushing I removed. I still wonder if they are standardized across aftermarket brands.... I doubt each company is having custom bushings made, and I would love to be able to buy a replacement set as mine have been in the car for over 15 years...

91banditt2

iTrader: (1)

Assuming these are the LCA’s ? I had these same ones, A couple years ago I called Lakewood about replacement poly bushings for these LCA’s and if I remember correctly I was told that they would sell just the bushings.

raptere

Well what do you know??? They do sell the replacement bearings...

Lakewood 20538 Lakewood Traction Bar Bushings - Red Polyurethane (holley.com)


Problem is they're $40 for 4 and you need 8 for both arms... If its $80 to replace the just the poly bushings and 99 for whole new rust free arms and bushings, I don't think It makes sense to replace bushings... I may see if I can figure out the actual bushing and see if I can buy it elsewhere for cheaper...

And they even give you the detail drawing!



The picture shows bushings that say 2142 on them, but I need to confirm the that is really what they are, or if they're using a generic picture...

UMI actually sells the 2142 bushings for much cheaper, but they do not confirm the dimensions...
Control Arm Bushing 2142 - UMI Performance Inc.

raptere

Well I got everything back together. Based on some moderate around town driving, it seems there could be some minor improvement. I have an AutoX race Sunday, so we'll see how it feels when pushed to the max, and I'll report back.

I'll also say, the small amount of grease that was in there was disgusting and brown, I cleaned all that out and lubed everything up with Superlube silicone grease which is translucent white and supposed to be good for poly, then gave it the 2 prescribed pumps once mounted up.

Maybe someone can explain this to me though... The installation instructions for all LCA's seem to first tell you to torque the arm bolts, but then pump the grease in the fittings. Problem is, once torqued there is nowhere for the grease to go, (or the air to vent) you have effectively sealed the grease volume once you torque the bolts tight. Is there a reason you are supposed to specifically do it this way? I instead, left all hardware loose, gave the two pumps of grease, then torqued down all the hardware to spec. I hope that modified method is ok, it made a lot more sense to me...

raptere

After another autox event and a couple days of driving around town and to and from work, I'd say this mod is making a slight improvement in handling. The car handled really well at the autox even, and I never had a feeling of anything loading up, or snapping free like is said to happen with poly/poly control arms. I actually managed to slide the rear end during a spirited right turn this morning, which has never really happened before, usually one well just lifts a little and only one wheel spins, I suspected due to the lack of articulation. At some point I still want to get some LCA's that can actually swivel, but for the time being, I think the effort was worth it.

BBU.COM

raptere

Just to update this thread, while I do recall thinking this modification made some noticeable difference, it is nothing compared to actual articulating control arms. I just ended up replacing the LCAs and Panhard Rod, with UMI's Roto/Roto parts, and the difference is way more obvious.

I go into more detail in another one of my threads below:
(Not So) Bare Minimum to Give Autox or Track Racing a Shot? - Page 3 - Third Generation F-Body Message Boards