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I have a lot of squeaks and noises coming from the rear suspension on my 17 year old WS6. I am thinking about replacing the LCAs and other suspension parts with BMRs or something like that. I use this car as my daily driver on nice days. I rarely take it to the track or beat on it. I want the car to be very streetable first and foremost. I have read that the poly bushings on upgraded suspensions can transmit a lot of road noise compared to the OEM rubber stuff.
I was wondering if anyone with upgraded poly bushings has noticed a big increase in road noise or any negative qualities when it comes to street driving. I have the general philosophy of upgrading things as they break, so I am leaning towards the upgrade, but I don't want the car to be noisier than it already is.
Generally though for street driving I wouldn't use regular poly bushings on the rear arms. They don't like to twist as well, so they'll be a bit stiffer when over uneven surfaces that twist the axle back and forth.
Not saying they wouldn't be streetable, but they aren't my first choice. I prefer either new rubber (I think you can get rubber bushings in BMR rear LCAs), or I personally went with Founders 3 piece poly joint arms. Aren't noisy like rod ends, don't deflect like rubber, but allow for some twist unlike straight poly. Brilliant design, if you ask me. And, they don't break the bank either!
Front, you can use poly on the UCAs no problem. Do NOT use a regular poly bushing on the vertical (caster) joint though, as that has actually resulted in breaking the control arm (that's how stiff poly can be in the off axis movement!). If you do aftermarket LCAs though, most use a rod end there so no worries. I've read about issues using tubular LCAs on the street however (things bending somehow) so I just stuck with factory LCAs and used new Moog rubber bushings.
That's just what I did, anyway. I'm by no means a pro but I've done a fair bit of research before buying stuff for my car while working off of a budget at the same time.
I am using 100% BMR suspension up front and read and have poly on all joints (lower a arm has roto one end) and I do have increased noise. Before I am flamed it is throughly lubed and nothing but street driven.
Zero issues so far with any breakage....knock on wood
Poly will not increase your NVH. We do have rubber bushings available for our rear lower arms, but the differences in noise are minimal. As for the big "poly bind" horror story... don't believe everything you read on the internet. While on an extreme and technical level, there is some truth to it, there is no realistic or measureable downfall to using them on a street car. On a competition level vehicle, you may see some differences. On a street car, there is no downfall. I have had customers with bushings that have lasted 6+ years in a street application with proper greasing. Give me a call and i can go over some options with you and get you setup with the right parts for your needs
Our first choice will always be heim joint suspension items. A good quality heim joint will make minimal noise, out last rubber/poly, and out perform anything else. With that said we do offer a poly/poly on vehicle adjustable lowers and panhard bar for those needing to replace their warn out stockers.
Nice thing about ours we only use Energy Suspension bushings.
"Don't believe everything you hear on the internet"
Well, a picture is worth a thousand words, so... Here is why I refuse to use poly on certain places that have to pivot counter to the axis of rotation of the bushing. This is an extreme example because it is the front caster bushing, and the rear control arms do not twist to that extent, but if poly is stiff enough to bust the steel arm, well, I don't want something to resist the movement that much. That, and how a better bushing option costs less anyway...
Correct. That is not how polyurethane is intended to be used. I always advise against putting it in an application like that. That is why we use a rod end in our arms. To be fair, I have seen arms break there with stock bushings as well. But in the sense we are talking about in a rear lower control arm resisting torsional flex or in a front control arm in the front position causing issues with caster changes from movement, it really is a non issue on a street car. This video illustrates the difference in rubber and polyurethane flexing. It is more resistant, but it is not solid and will allow for some movement. If we can move it by hand, your car won't have too much trouble doing it.
04-19-2017, 10:48 AM
Poly bushings 
