Poly/Poly LCA - Bind?
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From: Parkton, Md.
Poly/Poly LCA - Bind? I have read about what bind is and what creates it, but what does it feel like on a street car on public roads. How bad does it effect a street driven car that is never auto-x or road course raced. I would like to hear from someone that has experienced bind with a Poly/Poly LCA set up. I read alot of threads on this but never saw actual complaints on bind for a street car. I can see where there would be issues with an auto-x course, due to the tight turns and rapid transitions, just curious if this translate to the street.
Thanks for any info.
Thanks for any info.
i had poly/poly lca's on my car before any of my other suspension mods. turning i didn't notice any major problems but i could feel what people were talking about. never really bothered me. just felt a little edgy coming out of turns. i autox'd with them and nothing terrible happened. it's not like you're not gonna be able to turn. but they don't help.
i took them off when i lowered the car since i started going for handling. i'm going poly/rod now. found a set really cheap so i'll see how they work out.
i took them off when i lowered the car since i started going for handling. i'm going poly/rod now. found a set really cheap so i'll see how they work out.
I have read about what bind is and what creates it, but what does it feel like on a street car on public roads. How bad does it effect a street driven car that is never auto-x or road course raced. I would like to hear from someone that has experienced bind with a Poly/Poly LCA set up. I read alot of threads on this but never saw actual complaints on bind for a street car. I can see where there would be issues with an auto-x course, due to the tight turns and rapid transitions, just curious if this translate to the street.
Thanks for any info.
Thanks for any info.
My other complaints about Poly bushes in LCA's are the fact that they:
1. Need frequently need lubrication, otherwise significant stiction (static friction) is easily introduced. This causes excess friction, which then leads to the some of the "squeaks" and eventual wear, but that's not as big as a problem as the next reason.
2. As they age, they experience a phenomena common to almost ALL poly formulas which engineers refer to as creep (really, it exists in almost all common materials, however I'm constraining this comment for Poly vs. rubber). No matter how much you lubricate, they will creep siginificantly more than their rubber counterparts. This is because Poly is more "plastic" where as rubber is more "elastic."
Now, this is the material itself...even though there are poly/rod options for rear LCA's, I'm still one to say that if a poly bushing should be used in an LCA, then that poly bushing should be a "three piece" design similar to a "poly-ball" or a J-Joint (but those designs are more like spherical bearings and not so much like the "two-piece" poly bushing).
Really, for most outside dedicated "track and/or competition", Moog solid rubber bushings are the solution to the crummy stock "fluted" bushings in the rear LCA's. The poly bushing bind in the rear LCA location alone adds excess spring rate to an area that doesn't need anymore than already is present.
I wouldn't say that the poly bushings add spring rate in the way that many of us think of it. They will add roll stiffness, like having a big rear sway bar on the car. I'm not a big fan of poly bushings because of their excessive stiffness, and the creep issues. A spherical bearing is best, then use sway bars to keep the car level. Spherical bearings can be tiresome on the street, though, because they are really noisey. I think the Moog rubber bushings or 1LE bushings are better than poly for the street. A really good compromise is a spherical bearing and rubber (not poly) combination.
Good answers... and I like to see that!
Our rear axles work in the same way you see a front axle on a rock crawling truck or buggy because we both use solid axles. The axles are attached at the outboard ends by the LCA's. If you have LCA arms that don't flex, and you have LCA bushings that don't want to flex (in rotation) then the axle can't moves in roll freely from the car and when you hit a one wheel bump, or drop a tire into a dip or hole, instead of the the axle following it and minimizing the pull on the body, the body gets drug around more.
All poly LCA's work great for going straight.... and you can turn with them too, but you have to realize it's like adding more rear bar when cornering, except the bar is a nice linear motion and allows the axle to move more freely than sticky LCA's.
You generally don't see complaints in the traditional sense. What you might get are complaints about the way the car works in the situations above, but most folks don't really know what the difference is without trying a number of LCA's and seeing for themselves. And since most do these arms trying to kill wheelhop, which they can do very well, when that happens they tend to disregard other smaller details, especially if they are unaware of how it works.
I like the poly/rod myself as I find them to be the best combination. Lower noise from only one axle mounted rod-end (easily replaceable). Stonger than two urethane bushings, and no bind at all to effect ride or roll stiffness by stiction.
Our rear axles work in the same way you see a front axle on a rock crawling truck or buggy because we both use solid axles. The axles are attached at the outboard ends by the LCA's. If you have LCA arms that don't flex, and you have LCA bushings that don't want to flex (in rotation) then the axle can't moves in roll freely from the car and when you hit a one wheel bump, or drop a tire into a dip or hole, instead of the the axle following it and minimizing the pull on the body, the body gets drug around more.
All poly LCA's work great for going straight.... and you can turn with them too, but you have to realize it's like adding more rear bar when cornering, except the bar is a nice linear motion and allows the axle to move more freely than sticky LCA's.
You generally don't see complaints in the traditional sense. What you might get are complaints about the way the car works in the situations above, but most folks don't really know what the difference is without trying a number of LCA's and seeing for themselves. And since most do these arms trying to kill wheelhop, which they can do very well, when that happens they tend to disregard other smaller details, especially if they are unaware of how it works.
I like the poly/rod myself as I find them to be the best combination. Lower noise from only one axle mounted rod-end (easily replaceable). Stonger than two urethane bushings, and no bind at all to effect ride or roll stiffness by stiction.
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Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
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www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
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I don't mind them at all... as long as everything is tightened correctly and the adapter bushings for the rod-end are the correct size. UMI, which is the brand I sell machines their bushings to fit the metric bolts, not everyone does, some use English size spacers they buy which have some slop.
I think a completely rod-ended (double adjustable) set of LCA's is way too much for street in terms of noise or potential noise, as those have a rod-end bolted right to the body. The poly/rods bolt the rod-end to the axle so any noise you might get is muted and damped by the bushing on the body.
Honestly you get folks with a mix. Everyone has an opinion. I can't stand a car that sounds like a rattle-can, but I also don't mind maybe a little clunk that the radio easier covers at a very sane volume if it gets me better function for a particular use.
I think a completely rod-ended (double adjustable) set of LCA's is way too much for street in terms of noise or potential noise, as those have a rod-end bolted right to the body. The poly/rods bolt the rod-end to the axle so any noise you might get is muted and damped by the bushing on the body.
Honestly you get folks with a mix. Everyone has an opinion. I can't stand a car that sounds like a rattle-can, but I also don't mind maybe a little clunk that the radio easier covers at a very sane volume if it gets me better function for a particular use.
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
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From: Parkton, Md.
Thanks for all of the reply`s
I have read a lot of threads on this, but the above reply`s have been the best at explaining what and how bind effects the vehicle. I did something backwards, I bought UMI Adj. LCA(poly/poly of course
) before I researched this issue. I purchased the new poly adj. end that can be screwed off, so maybe I can return these to UMI and get the rod end. They were not installed so maybe I can catch a break.
Thanks again for the help, and have a good holiday!
I have read a lot of threads on this, but the above reply`s have been the best at explaining what and how bind effects the vehicle. I did something backwards, I bought UMI Adj. LCA(poly/poly of course) before I researched this issue. I purchased the new poly adj. end that can be screwed off, so maybe I can return these to UMI and get the rod end. They were not installed so maybe I can catch a break.Thanks again for the help, and have a good holiday!
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From: Knoxville, TN
There might be one of my problems with the BMR SFC that I have connect with the lower control arm with their supplied bolt, I may need to find bolts that are correct when I decide to do this.
Thanks for all of the reply`s I have read a lot of threads on this, but the above reply`s have been the best at explaining what and how bind effects the vehicle. I did something backwards, I bought UMI Adj. LCA(poly/poly of course) before I researched this issue. I purchased the new poly adj. end that can be screwed off, so maybe I can return these to UMI and get the rod end. They were not installed so maybe I can catch a break.
Thanks again for the help, and have a good holiday!
I have read a lot of threads on this, but the above reply`s have been the best at explaining what and how bind effects the vehicle. I did something backwards, I bought UMI Adj. LCA(poly/poly of course) before I researched this issue. I purchased the new poly adj. end that can be screwed off, so maybe I can return these to UMI and get the rod end. They were not installed so maybe I can catch a break.Thanks again for the help, and have a good holiday!
Just my suggestion.
Giddswat, did you forget my number?
Your plan won't work. Your arms cannot be converted to any of the screw on type ends (be they what you pictured or a rod-end). The ends of your arms are not interchangeable. Here's what you have by your description:
If you want a poly/rod combo, it's going to mean a new set of LCA's like these: http://www.stranoparts.com/partdetai...D=96&ModelID=7
Your plan won't work. Your arms cannot be converted to any of the screw on type ends (be they what you pictured or a rod-end). The ends of your arms are not interchangeable. Here's what you have by your description:
If you want a poly/rod combo, it's going to mean a new set of LCA's like these: http://www.stranoparts.com/partdetai...D=96&ModelID=7
__________________
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
www.stranoparts.com --814-849-3450
Results matter. Talk is cheap. We are miles beyond the success anyone else has had with the 4th gens, and C5, C6, C7 Corvettes,
10 SCCA Solo National Championships, 2008 Driver of they Year, 2012 Driver of Eminence
13 SCCA Pro Solo Nationals Championships
2023 UMI King of the Mountain Champion
Thread Starter
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From: Parkton, Md.
Yes Sam I still have the number
I just ordered direct from UMI due to the sale they were having. I should have looked into this a little more, a little sooner. They are still new in the box, so I will call UMI after the holidays and see if they can exchange the poly end. I ordered the Adj. LCA you see below, but they have the new poly end instead of the rod end which is shown. I think I can just remove the poly end and replace it with the rod end. I think that screw in poly end is a new product from UMI.
Thanks Sam for the input on this!!
Mike Giddings
I just ordered direct from UMI due to the sale they were having. I should have looked into this a little more, a little sooner. They are still new in the box, so I will call UMI after the holidays and see if they can exchange the poly end. I ordered the Adj. LCA you see below, but they have the new poly end instead of the rod end which is shown. I think I can just remove the poly end and replace it with the rod end. I think that screw in poly end is a new product from UMI. Thanks Sam for the input on this!!
Mike Giddings
Last edited by Giddswat; Dec 25, 2008 at 07:33 PM.
DO THIS!! I just put them on my car and there is no wheel hop anymore and it is so much cheaper than buying new lca's. It is incredible the difference I feel in the rear with just some new bushings. Just my .02
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From: Parkton, Md.
Yes Sam I still have the number I just ordered direct from UMI due to the sale they were having. I should have looked into this a little more, a little sooner. They are still new in the box, so I will call UMI after the holidays and see if they can exchange the poly end. I ordered the Adj. LCA you see below, but they have the new poly end instead of the rod end which is shown. I think I can just remove the poly end and replace it with the rod end. I think that screw in poly end is a new product from UMI.
Thanks Sam for the input on this!!
Mike Giddings
I just ordered direct from UMI due to the sale they were having. I should have looked into this a little more, a little sooner. They are still new in the box, so I will call UMI after the holidays and see if they can exchange the poly end. I ordered the Adj. LCA you see below, but they have the new poly end instead of the rod end which is shown. I think I can just remove the poly end and replace it with the rod end. I think that screw in poly end is a new product from UMI. Thanks Sam for the input on this!!
Mike Giddings
Lesson learned. (I should have looked into this a little more, a little sooner.) 