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Quite simply, any new thoughts or actual analysis on these causing snap/ oversteer or other meaningful undesired handling characteristics.
Or have these suffered a somewhat Samurai/ Corvair esque unjustified bashing
Yes my curiosity is primarily being driven by my cheapness, but also oddly UMI poly rear arms have a much less punitive overseas shipping charge than anything *apparently* more handling friendly across after market manufacturers
I have Kenny Brown rear control arms with poly bushings on body side, and spherical rod ends on axle side. I recently had the rear axle out of my car and was shocked by how difficult it was to rotate the rear control arms with the poly mounts. Never paid any attention to it before but I noticed this time!
Unless there is some kind of fancy dancy bushing on the market, I don't see freeing up movement without using spherical rod ends at the body side. And that would be punishing from a noise & vibration perspective.
"Snap oversteer" doesn't exist. Fantasy land, invented by somebody that didn't have access to them, and wanted to sell something more expensive. Not sure how if stock rubber bushings, with their basically frozen-in-place behavior can be good; and rod-ends, with essentially ZERO friction, can be good; but something in between can be Satan incarnate. Strikes me as marketing hype. SOMEBODY is selling SOMETHING. Hold onto your wallet.
I've had rear LCAs with poly bushing on my car since... well, since before most of the people on this forum were born. Never had any such problems.
Sure, they have SOME friction, but compared to OE type rubber, it's negligible. Probably less than 20 inch-pounds to rotate them around their bolts. About what it takes to turn a freshly installed rotor on a new front wheel bearing.
Mine are the old Lakewood square-tubing variety. Never have had to change out the bushings. I grease em once every 10 or 15k miles though whether they need it or not.
Well i had umi lower rear control arms with poly bushings and quickly removed them and put in the stock ones with rubber. It would oversteer bad around corners always wanting to come around when getting on the throttle. It is less noisy and is more balanced with the stock arms and rubber bushings. The rear end needs to pivot and it wasnt with poly and tubular control arms. So dont waste your money on them imo.
So, please explain how stock rubber ones encourage "pivot".
The reason it was loose compared to the stock crap was ACTUALLY because the poly ones DID "pivot" freely, but the stock rubber ones DID NOT.
Go ahead, it's OK, admit that you got sucked in by the deceptive ad copy and mis-attributed what you GENUINELY experienced (note that I am NOT calling you a liar about what your car did, or any such thing), and blamed what you felt on what the ad copy told you. It's OK, we all get bamboozled once in awhile by seductively worded ad copy and colorful shiny things and all stuff such as that, it's not shameful to admit it, you can still be a man (or other adult person) and admit you're wrong about what you blamed for what happened, and we won't shame you.
Probably less than 20 inch-pounds to rotate them around their bolts. About what it takes to turn a freshly installed rotor on a new front wheel bearing.
Is it really that loose? Mine is more on the order of 20 lb-ft with the bolt torqued. Maybe my bushings have deteriorated more than I thought. 20 years old but only driven the last 5 years, less than 8K miles.
Or maybe mine are some kind of hard rubber and I should have paid closer attention.
I ditched poly long ago. Tired of the squeaking and groaning when cold even with lube.
When I did remove the poly rear control arms, the poly had compressed enough to just fall out of the shells. They were only in for 5 years or so?
I also hated the way the rearend of the car hopped sideways when cornering and hitting an expansion joint. Much smoother with stock rubber or rod end control arms. Although the rodends are noisier, they have less binding than poly.
When autocrossing my 91 vert I could feel the poly control arms binding and then releasing on tight turns and hard braking . Switching to rod ends make the car much more predictable but too harsh for the street. When I bought a different car to autocross I when back to stock arms on the camaro and it is much more pleasant to drive on the street. Boxing the stock arms might be a good compromise. Also no matter what I used to grease the poly they squeaked . With the top down on a tree lined road it sounded like a flock of birds was following me.
I have the Lakewood ones. https://www.summitracing.com/parts/lak-20140 Maybe 30 yrs old now. The bolt clamps down on a tube going through the middle, and the bushing pivots freely on it. No noise, no steering weirdness, no binding, no non-existent fantasy land "snap oversteer", no particular road noise or harshness in fact not noticeably different from stock except they don't bend in my hands, no ... nothing. Just, they work. Very simple. Very easy. Very cheap.
They might need new bushings though, haven't really paid much attention to them in a REALLY long time.
Last edited by sofakingdom; 04-13-2021 at 02:13 PM.
I used the Founders Performance with the 3 piece poly bushing. Best of both worlds. They have been on the car for 4 yrs now and still on the original greasing with no squeaking. These are smooth riding and great for handling IMHO.
Good to see long term feedback on these and I have been considering them. Just, at a principle level , need to get my head around paying more for shipping than the part. Or perhaps I could wait for that Britain- America trade agreement that the brexiteers promised as part of their charming populist rhetoric
I have Kenny Brown rear control arms with poly bushings on body side, and spherical rod ends on axle side. I recently had the rear axle out of my car and was shocked by how difficult it was to rotate the rear control arms with the poly mounts. Never paid any attention to it before but I noticed this time!
Unless there is some kind of fancy dancy bushing on the market, I don't see freeing up movement without using spherical rod ends at the body side. And that would be punishing from a noise & vibration perspective.
Delrin, any of the industrial steel or aluminum with nylon lining bushings (though most are pretty limited WRT to torsional motion...
Originally Posted by sofakingdom
"Snap oversteer" doesn't exist. Fantasy land, invented by somebody that didn't have access to them, and wanted to sell something more expensive. Not sure how if stock rubber bushings, with their basically frozen-in-place behavior can be good; and rod-ends, with essentially ZERO friction, can be good; but something in between can be Satan incarnate. Strikes me as marketing hype. SOMEBODY is selling SOMETHING. Hold onto your wallet.
I've had rear LCAs with poly bushing on my car since... well, since before most of the people on this forum were born. Never had any such problems
You had a few posts about what they got, and I'll add to that. These cars really do have lightswitch-like oversteer tendencies with poly bushings binding back there. I've done 3 different things over the years on cars I was seriously autocrossing (and some that I was pretending to 😋 ):
switched back to rubber, it's surprising how much tuning you can do with different rubber bushings
switched to spherical ends (which have their own problems)
Drilling, grooving, and installing zerks on poly bushings and greasing them before every event with premium grease. You end up with something that works right in between rubber and rod ends.
Sure, they have SOME friction, but compared to OE type rubber, it's negligible. Probably less than 20 inch-pounds to rotate them around their bolts. About what it takes to turn a freshly installed rotor on a new front wheel bearing.
Mine are the old Lakewood square-tubing variety. Never have had to change out the bushings. I grease em once every 10 or 15k miles though whether they need it or not.
Originally Posted by sofakingdom
So, please explain how stock rubber ones encourage "pivot".
The reason it was loose compared to the stock crap was ACTUALLY because the poly ones DID "pivot" freely, but the stock rubber ones DID NOT.
Go ahead, it's OK, admit that you got sucked in by the deceptive ad copy and mis-attributed what you GENUINELY experienced (note that I am NOT calling you a liar about what your car did, or any such thing), and blamed what you felt on what the ad copy told you. It's OK, we all get bamboozled once in awhile by seductively worded ad copy and colorful shiny things and all stuff such as that, it's not shameful to admit it, you can still be a man (or other adult person) and admit you're wrong about what you blamed for what happened, and we won't shame you.
Originally Posted by sofakingdom
That's all very interesting.
I have the Lakewood ones. https://www.summitracing.com/parts/lak-20140 Maybe 30 yrs old now. The bolt clamps down on a tube going through the middle, and the bushing pivots freely on it. No noise, no steering weirdness, no binding, no non-existent fantasy land "snap oversteer", no particular road noise or harshness in fact not noticeably different from stock except they don't bend in my hands, no ... nothing. Just, they work. Very simple. Very easy. Very cheap.
They might need new bushings though, haven't really paid much attention to them in a REALLY long time.
You did get one thing right here, rubber bushings do work fundamentally differently than poly or spherical/rod ends. Rubber do not "pivot" in the pocket usually, they typically stick and they actually twist. They add to both the spring rate and the dampening (what the shock absorbers do), so technically if you just swap out rubber bushings you will have a lower wheel rate at the suspension, but people rarely do that without going with stiffer/lowering springs and performance shocks. Various spherical ends act like bearings, both in rotation and twisting. No dampening at all. There's a Russian Youtube channel that posted a video of replacing all the bushings in a car with bearings and the results, it's an interesting watch. Poly is something in between. Properly lubed they could be considered something in between. When they are lubed they're essentially bearings on the pivoting axis and they give some in the twisting axis like a rubber bushing. The problem is that they can bind even with some grease on them, you need to turn that **** into a slip and side before you can really use it (ask your girlfriend if you don't understand 😁 )
My guess is that your bushings are either worn out or you just don't use the car in a way that you notice.
Originally Posted by TTOP350
I ditched poly long ago. Tired of the squeaking and groaning when cold even with lube.
When I did remove the poly rear control arms, the poly had compressed enough to just fall out of the shells. They were only in for 5 years or so?
I also hated the way the rearend of the car hopped sideways when cornering and hitting an expansion joint. Much smoother with stock rubber or rod end control arms. Although the rodends are noisier, they have less binding than poly.
It's amazing how even worn out they can still squeek. For the most part if they're squeaking a lot they're worn out and often the noise i that they've separated from their leaves. I've posted this a few times recently, there's something going on with modern poly bushings. Poly bushings used to be a pretty much permanent swap. You put them in and they were good forever unless you got them too hot. This would be a problem with the rear bushing in the front left control arm (the exhaust runs right by it) and motor mounts, they would get hot and liquidy and just run out/distort. I have a set of control arms I put in my '83 in about 1992 that besides being dirty look pretty much new. Newer poly bushings don't seem to last as long. Better ones shrink, worse ones just turn into a powder. I'm not sure what changed but I've been having even name brand poly endlink bushings disintegrate in a year or 2.
Originally Posted by vinny R
I used the Founders Performance with the 3 piece poly bushing. Best of both worlds. They have been on the car for 4 yrs now and still on the original greasing with no squeaking. These are smooth riding and great for handling IMHO.
I've never had a set of those in my hands, are all 3 parts poly, or is one or more of them a hard plastic like Delrin or nylon?
Last edited by 83 Crossfire TA; 04-14-2021 at 04:34 PM.
Various spherical ends act like bearings, both in rotation and twisting. No dampening at all. There's a Russian Youtube channel that posted a video of replacing all the bushings in a car with bearings and the results, it's an interesting watch.
Not to hijack, but has anyone boxed-in the stock LCAs? And if so, how effective is it in improving performance?...
That's what I had my poly in back in the early 90s. I boxed a spare set and put in poly.Once I got tired of the poly i went to double rod end tubular and ran those for 15ish years. Recently went back to rubber in the boxed units.
I've never had a set of those in my hands, are all 3 parts poly, or is one or more of them a hard plastic like Delrin or nylon?[/QUOTE]
It has been awhile since I put them in but I believe the center ball is a hard plastic. I used the "sticky" grease supplied with them to lubricate each piece as you assemble them into the control arm.
Not to hijack, but has anyone boxed-in the stock LCAs? And if so, how effective is it in improving performance?...
Back in the 90's when I was very serious about autox I ended up boxing in stock LCAs with stock rubber bushings. This is what I went to after I decided that I needed to soften up the rear some and went back to mostly rubber in the back. I actually preferred that setup.
Originally Posted by TTOP350
That's what I had my poly in back in the early 90s. I boxed a spare set and put in poly.Once I got tired of the poly i went to double rod end tubular and ran those for 15ish years. Recently went back to rubber in the boxed units.
The trick with poly bushings, besides constantly lubing them is to use them in something like stock LCA's that will flex a little and that will prevent some of the possible binding. Boxing them makes them as stiff as any aftermarket ones and they will bind the same.
FWIW, I've run stock boxed arms with rubber bushings (I tried poly and didn't like them) on 2 cars, one was boxed with 1 or 1.25" x 1/8" flat bar, the other was boxed with some 16ga sheet cut to shape, I always liked the ones done with the flatbar better but I don't have any evidence that they worked better besides that I liked them better.
Fwiw I’m running the full Midwest chassis rod end control arms and pan hard bar on my third gen. Only put maybe 75 miles on it so far. But I haven’t felt any negative effects so far. Car feels very tight on the road, but I did pretty much the whole suspension at once, so I can not say that they made any more of an improvement than another part of the chassis. I don’t notice any abnormal harshness over the factory components or the poly stuff I had on before the rod end parts.
I did swap the poly control arms and panhard bar from it to my forth gen, and I’d be lying if I said I noticed much any difference than factory. I pretty much daily my 4th gen in summer too.
So, please explain how stock rubber ones encourage "pivot".
The reason it was loose compared to the stock crap was ACTUALLY because the poly ones DID "pivot" freely, but the stock rubber ones DID NOT.
Go ahead, it's OK, admit that you got sucked in by the deceptive ad copy and mis-attributed what you GENUINELY experienced (note that I am NOT calling you a liar about what your car did, or any such thing), and blamed what you felt on what the ad copy told you. It's OK, we all get bamboozled once in awhile by seductively worded ad copy and colorful shiny things and all stuff such as that, it's not shameful to admit it, you can still be a man (or other adult person) and admit you're wrong about what you blamed for what happened, and we won't shame you.
Sofa, you’re working in the wrong axis. You’re talking about the arm “swinging” around the bolt. The torsional resistance that causes snap oversteer is along the same axis as the control arm, wherein the control arm must rotate on an axis perpendicular to the bolt. This is the movement that the control arm bushings see as the body rotates relative to the axle when cornering.
Due to its softer nature, rubber bushings do allow much more rotation around this axis than polyurethane.
I have all UMI Roto-joint stuff in the back of my car. Its UhhmAzing.
I did the rear end first, and the incredible feedback that I got from the rear-end made the front feel 10x worse. Nothing in the front changed, but the difference in the way the front and rear tracked amplified every flaw in the front end.
Maybe its not for everyone, but its definitely for me.
I used the Founders Performance with the 3 piece poly bushing. Best of both worlds. They have been on the car for 4 yrs now and still on the original greasing with no squeaking. These are smooth riding and great for handling IMHO.
I have the J&M version of these and going on 16 plus years. Very smooth/non binding and yes all three parts are poly. No complaints/squeaks here.
https://www.medievalchassis.com/prod...trailing-arms/ These are spherical bearing bushings some of the dirt track racers use on g body trailing arms. They are usually illegal on most racecars rules. I've never used them but they would probably work great.
Had to post this...I had the poly and the snap steer was terrible- founders poly poly. Sure it hooked well with no wheel hop and under light corners handled fine, this was a 4th gen w/ 285/35 18`s all around with umi 2 inch drops and bilstiens so plenty capable. It ended up getting so bad on high speed corners I had to make a change. I had these built- they are not for the light of wallet BUT these solved every problem I had you see...I live off a dirt road so open bushings get blasted with clay dust..so grease is out of the question. I found a local place that was building these arms for another chassis and had them build a set to my spec...these totally changed the car into a corner eating on the throttle pass you in the corner car. The specs:
The rearend side uses a cross axis ball joint, this is a German made harden steel cross pin w/ 1/2 ID 2.5 wide, the joint is totally sealed and offers 22.5 degree of articulation, this is the magic of the set up. The rod end or bushing cup is chrome moly tig weled with an adjustable threaded end, mild steel 3/16 wall tubing then a 2.5 inch high durometer bushing. So everything is sealed weather tight, the bushing needs no grease and they ride quiet down the road and put down the power in turns..the one word I see missing from this thread is Articulation...that is what the rear has to do in turns, it cannot bind , if it does it is lifting pressure off the tire, hence why it skips easily over a bump in a turn. I found out long ago what bind can do, in my drag car an 85 third gen, the spohn torque arm has a shackle at the cross member, there is a lock nut on there for a reason, I had it torqued down, the car would launch off the trans brake great but immediately fall on its nose after the initial hit..found that tight bolt and loosened it so the T/A could go fore and aft during suspension travel...right out of the high 1.3`s to low 1.2 60' times with that adjustment
I can have these built if anyone is interested, they made such a difference coming from poly I had thought for a while to offer these but there are so many trailing arms on the market and a few offer similar function but competition is really aggressive in this market so I`ll just stay in my own wheelhouse.
04-12-2021, 04:15 PM
