Well roughly 2 weeks ago I bought a set of BMR adjustable LCA's from a buddy who was going to install them on his car but never did (sold the car) so he sold me them new for $140. They retail for $240. They are poly/poly LCA's. I haven't really driven the car since they were installed.

A couple days ago I ordered a UMI on-car adjustable PHB, also with poly/poly bushings. That is supposed to be installed on Monday.

It wasn't until yesterday that I heard of "suspension bind" and it has me a little worried. Current mods are in sig (not tuned). Car has 2.73 gears and 25k miles. My plans for the car are to make it a street/strip car. It'll be a primarily street car: 50-100 miles per week, maybe 1-3 trips to the strip per year. I plan on adding SFCs, a ~3600 stall converter, built rear, cam, and built trans. Possibly 100 shot of nitrous eventually.

Basically I need to know if I'm going to be alright with having poly/poly pieces on my car for how it will be used. Most of my acceleration is all in a straight line unless I'm kicking the back end out as I make a turn on purpose. Sometimes I like to get in it on the twisty roads as well but that's rare.

 

Unless you get to a point where you experience unwanted oversteer, I would say you are ok. If anything, drag racers want to have more swaybar to keep the rear end level. And that's essentially kind of what the bind of the poly poly arms are acting like.

I would say no worries..

 

For a street/strip setup you won't have any issues with using the poly-urethane bushing parts. I think the whole binding deal is generally blown out of proportion and really effects very few people depedning on there driving and what they are doing with the car.

 

There is an immense level of debate on the binding topic and it is certainly something greatly exaggerated. On paper, suspension bind is something that should occur just by the design of the rear suspension and its restricted travel path. From the factory, the rear lower control arms feature a soft durometer rubber bushing that can be easily distorted under suspension movement. The benefit of polyurethane is that it does not distort as easily...which is also its biggest drawback. In a drag racing application, the rearend will typically move uniformly and the elimination of the bushing distortion can help traction and performance. In a handling application, the rear suspensions will compress on one side while extending on the other. This causes the rearend to move in an altered manor where one side is higher than the other. Rubber bushings don't have a problem with this and just distort to compensate. On a poly bushing, it's less likely to distort to the same level and will increase the roll-rate stiffness - binding. How extreme this increase is depends on the durometer of the bushing and the amount of force being applied to the suspension. It effectively acts like a poorman's sway bar, so to speak.

The level in which it usually "binds" goes unnoticed by your typical driver or in your typical driving scenario. In a handling application on a road course, you'll probably feel the greater stiffness in the rear. On the street, probably not. So take everything you read with a grain of salt because its made out to be much more severe than it actually is. Ideally, you don't want ANY bind because you want ever suspension component to do just one job. It's when parts start to share jobs that you start to create a problem. I feel that for you with your application you won't have any problems at all.
- Kevin

 

I have Poly everything and I applied plenty of grease when doing the installation. I have NO binding. All the talk about binding is B.S. The only binding I get is when I eat too much cheese. lol.

 

This is a good post!

 

.. and this is not, lol

 

Agree, great info here.

Plenty of fast bind-free cars on poly out there. Proper lubrication, maintenance and torque values are your friend.

Time to go relax with a block of cheese...

ramey

 

Rubber bushings require no lubrication or maintenance, and they don't bind.

What are they gonna sell next, tires made of polyurethane? Those would be some "low deflection" tires!

But in all seriousness... I'm sure poly bushings aren't the worst thing in the world, but why spend money and take the time putting something on your car that isn't really an improvement over stock? Yes the tubular control arms look badass, but I would opt for a rubber bushing over poly if possible (I know BMR has that option for their rear LCAs).

 

Point taken but..............my Poly Bushings are an Improvement over stock by at least 100%. It handles better, I have much more control.

 

Yes I've heard this from my friends with their poly suspension, but I think tuning your handling is better accomplished with shocks, springs, and sway bars.

 

Lets get this strait here. You yourself said your car feels like it wants to spin out when being pushed (when talking about going around an entrance/exit ramp on the highway), that a trait of suspension bind. The wheel rate spikes up because the bushings are binding up parts that are supposed to be moving freely, causing the car to feel more like its on ice. This sounds like much less control to me.
I totally believe the car rides stiffer, and your initial turn-in is quicker all due to the less deflection, but that doesn't outweigh the FACT that the poly bushings DO and WILL bind, whether you feel it or not.
Next your car has 300,000 miles according to you, and if the stock bushings were still in place they were more than likely completely shot - poor comparison.

If poly bushings in suspension piece that need to articulate are good for handling, then why don't race cars built ground up for handling use them? Why don't high end super cars use them? Why do they instead try and get the MOST amount of smooth articulation they can?

 

I think you make **** up as you go along. I said as a question in another post about some other suspension piece you were trying to push...that I can get off the cloverleaf at 50 mph with no problem, where in that statement do you read my car has a push. Yes my car has now 307,000 mile on it and still has the original bottom end. I know how to take care of a vehicle even you should understand that by the mileage. Let me explain this to you so there is no misunderstanding..........I bought this car New in 1997 and the Poly Bushings in my car Now make it handle BETTER THAN NEW,got it? I DON"T DRIVE A RACE CAR! This is my DD. I rebuilt my 1st engine in 1971 in High School of which I spent 4 years 4 hours a day learning. Unlike some of the youngsters here and other sites you sell parts to I understand! Now don't get me wrong it's your business to sell parts and make a living that's all well and good. But....... don't come here and try and blow smoke up my *** and make me look stupid. Enough said...get your facts right.

 

I love it how when someone gets uptight because they are challenged and they start listing off everything they've done in the past and how long they did it, when it really has very little bearing on the subject. Building engines means squat about suspension.

I'm no suspension expert either, but simply looking at the rear axle movement from a pure geometrical point of view, and knowing the properties of various materials, it is quite obvious that poly will bind when the axle doesn't move uniformly. How much it binds and how much it matters can be debated. But the poly properties and suspension geometry flat out guarantee binding to at least a degree.

BTW, technically the OEM or 1LE rubber bushings bind also. They actually bind in all directions of movement since they twist, not rotate. Poly rotates one axis and binds on the other (and a lot faster than rubber). So one axis it is vastly superior to rubber, the other axis it is inferior (for the rear suspension anyway, in some cases you don't want a second axis such as front UCAs).

 

Read my post, I said "when being pushed", i didn't say "it has push".
Here is your post:
https://ls1tech.com/forums/16278509-post31.html

In what way does it handle better? Explain. More grip? Better balance?

Hey, me too! Mines a total street car, and technically my DD.
I don't sell parts, im not a sponsor/vendor on here. And clearly from your posts you do not understand squat for suspension.

Im not making you look stupid, you are doing that all on your own.

 

 

Uh oh.. you jinxed us... lol

 

Well I'm hoping that the binding won't be a concern and hopefully it won't oversteer too bad. I don't autox or anything in the car, the only thing I would be concerned about really is accelerating during a turn to slide the back end out.

Would adding more suspension parts lessen any binding at all? I.e. aftermarket sway bars and shocks?

I could possibly do one of those before I buy my torque converter, I was thinking shocks but I'm not sure. I definitely need sub-frames on the car asap though, that has to be first.

 

No but like we said.. I don't think you have anything to worry about. It's hard to tell what it would be like. Given your situation, your not doing any autox or track events.. just an occasional strip visit.

Nothing to worry about for your application sir

 

- Kevin