Spherical "Bushings"

**64oeg** · 01-07-2006, 06:47 PM

Originally posted by Matt Rowe@Jan 4 2006, 09:14 PM
But just as a reference point I don't see sphericals being any more expensive than the alternative. A set of front a-arms for a neon (the only way to get stock bushings) is $472. The costs to put a set of spherical's in was $120 and it will be $45 dollars to replace the bearings, or antoher $472 to put new arms in when the bushings wear out at a faster rate. So the cost issue doesn't fly with me.

[snapback]70100[/snapback]

BZZZZZZT Wrong answer Matt. I just picked up a set of front control arm bushing, (stock-oem) from the dealership just last week for a 1st gen Neon. And I also know that they are available for 2nd gens.

Sorry for the thread Hi-jack. And IMHO, SB as bushings are legal. Cool thread.

George

**dickita15** · 01-07-2006, 06:57 PM

Originally posted by ddewhurst@Jan 7 2006, 04:34 PM
***Without this technology I will need to raise the car at least 2 inches and raise my spring rate a lot. ***

Dick, talk me through this deal why you would have to raise your car 2 inches.

[snapback]70362[/snapback]

David
When I wrote that and even when I first read your reply I was pretty sure of myself but now I am having second thoughts. I bought my car in 98. It had stock upper links and spherical bearings replacing the rear bushings in the lower links. It also had illegal coilovers in the rear. I replaced the improper springs and started racing the car. With my level of talent I could not sort the car. It would understeer and then snap oversteer. I learned it was a suspention bind problem. I then put in a Susko trilink, two more bearings and foam bearings in the uppers. My assumption is that if I gave up the bearings the bind would return but now that I think about it I have never run the car with the tri link and a stock style lower link bushing so I am not sure. Have you.

thanks for keeping me honest

**dickita15** · 01-07-2006, 07:09 PM

Originally posted by Andy Bettencourt@Jan 7 2006, 05:16 PM
Let me ask this question:

If you accept that SB's are allowed under the "Bushings of alternate material are allowed" premise, what COULD you do with these rules?

1. Valve guide material is unrestricted.

2. Alternate water pump, alternator, power steering, and
crankshaft pulleys of any diameter or material may be used.

Is it wrong of me to assume that those that are willing to accept a SB as a "change in material" over a rubber bushing would or could do just about ANYTHING with their valve guide or pulleys - including changing the technology in some way? Not sure what you would do, but I would think those 'pro SB' people would effectivly say that these are now free and wide open, no?

Just coming at it from a different point. I don't believe Bushings are "free", I believe that you can simply change the material - like the rules seem to state - and those who believe SB's to be legal, I think you think they are 'free'. Again, no?

AB

[snapback]70368[/snapback]

Andy, great question.

Let be take a shot at this. For the valve guides I would think that they would have to be of the same dimension as the original, just as my bearing cartridges are. But it would certainly open the door to a valve guide that had say different heat conducting properties.

For the pulleys it seems to me to be even more open, as long as it does not perform a prohibited function. I think for instance you could probably change to a serpentine belt. I do not think you could change to a chain drive because they would not be pulleys anymore.

I will concede the the bushing must be made of material, so I guess anti matter is out.

**Greg Amy** · 01-07-2006, 09:09 PM

Originally posted by turboICE
...what are these additional functions that they perform when installed in suspension arms not performed by a part you deem legal?

I don't believe I invoked the "prohibited function" clause, however the answer seems intuitive: there are functions that a spherical bearing offers that a simple bushing does not. If they did not offer improved function, why are you and others so adament about using them? If you believe they do not offer any additional function and thereby improve your performance, why did you spend the money on them?

My core argument is, and always has been, that the only change allowed to suspension bushings is "the substance or substances out of which a thing is or can be made."

Originally posted by turboICE
...your complaints would not be satisfied with the simple change to unrestricted language since it is your belief that SBs in no way can be bushings.

That is not central to my argument (see above). If the rule read "bushings are unrestricted" rather than "bushing material...is unrestricted" and you can make a reasonable argument that spherical bearings are bushings, then you'd have a leg to stand on. But that ain't what the rule says, is it...?

Originally posted by turboICE+--><div class='quotetop'>QUOTE(turboICE)</div>

I hardly think the definition of a closed mind is disagreeing with you...[/b]

Nor did I intend it to mean that. What I mean is that I see folks such as yourself that have long ago convinced themselves that these things are legal and can't seem to see this from any other perspective, especially one that reads the rules as they are written.

Originally posted by dickita+--><div class='quotetop'>QUOTE(dickita)</div>

I must admit Greg you do seem a little more close minded that usual on this one. Not typical for you.[/b]

Why, Dick? Because I've yet to read an argument that changes my mind? I've simply not heard any argument compelling enough to change my mind. In fact, the vast majority of the arguments have further convinced me of my position.

If that's the standard, doesn't that apply across the board?

<!--QuoteBegin-dickita@
(SBs) still meet the definition of a bushing in the GCR...

Even if we were to accept that argument, bushings are not unrestricted, therefore you do not have carte-blanche to replace your bushings with anything you want. Only the material they're made of is unrestricted.

<!--QuoteBegin-dickita
Without this technology I will need to raise the car at least 2 inches and raise my spring rate a lot.

I understand your plight, but how is that germane to the discussion? We all have limitations we must work around; my McPherson strut suspension design sucks so bad that I basically cannot lower my car much less than stock ride height; do I get to use some technology to accomodate that so I can lower my car as much as the multi-link Acuras can?

Interesting sidebar: I met with several car and flying friends this afternoon, guys that know cars but who have no association with our racing of any kind. I asked each of them, "if the rule states that 'suspension bushing material is unrestricted' what would that mean I could do to my car?" Each of them - to a person - responded with answers like 'poly bushings' or 'Delrin replacement bushings' or 'solid steel bushings.' When they ran out of other ideas I mentioned to them that there are persons within our organization that believe it is legal to replace factory bushings with cassette-type or spherical bearings; to a person they looked at me like I had two heads. They all thought the idea was way out of bounds and one guy that races local asphalt roundy-round even said something to the effect of 'try that (stuff) at our local track and you'll get asked to go home and never show up again - if you're lucky.' What I find really ironic is one guy actually used the words "tortured interpretation"!

It just seems ridiculous that a simple allowance in material has resulted in folks totally redesigning their suspension bushings. If you think that's OK, then there's really nothing left to discuss; you will never convince me otherwise. - GA

**pfcs** · 01-07-2006, 09:21 PM

ask Dick Rutan.

**lateapex911** · 01-07-2006, 09:22 PM

Dick, right, the tri link SBs are completely legal. And the upper "air bearings" are fine too, LOL. But the lower longitudinal arms locating the axle are the "issue".

In theory, you really shouldn't have to raise the car 2" if the SBs were removed, but you might get some extra compliance that would be undesired if you went to a stock rubber type of bushing, OR, you could go to a polyurethane/delrin type that would of course, increase wear and maintenance.

Now, there is a Porsche company that makes a product called "Polybronze", which is great. I use them on my 911, and the bushing includes a grease channel and zerk fittings. Much more expensive than the SBs, LOL, but equally effective...

But....would the polybronze solution be legal?? It uses TWO materials...and is a design change.

A general comment:
I have done prototype work that used what the engineeer spec'ed as "Lord bearings". They are basically a torsion spring. Think of a cylinder 1.5" x 1.5", in metal. then the core is filled with rubber. The center has another metal sleeve running through it, splined in certain cases. The outside can be splined as well. They are available in different rates.

When I saw them, I commented to the design engineer, "Hey, these look EXACTLY like automotive suspension bushings, except for the splines"

"Bingo" he said.

**turboICE** · 01-07-2006, 10:39 PM

Originally posted by GregAmy
I don't believe I invoked the "prohibited function" clause, however the answer seems intuitive: there are functions that a spherical bearing offers that a simple bushing does not. If they did not offer improved function, why are you and others so adament about using them? If you believe they do not offer any additional function and thereby improve your performance, why did you spend the money on them?

There is a huge difference between improved function and additional function. I have stated several times that SBs function better than OEM or poly replacement bushings. I am equally certain that poly functions better than OEM rubber. So I go back to our discussion before: Is your objection that SBs perform the function of a suspension bushing in the best way available? You had said no - but you are back to the improved function being part of the problem. The objective behind any aftermarket replacement part is because it is an improvement either in performance or cost. Improved function is not illegal and improved function is not an addtional function - it is the objective of most of the modification rules in improved touring.

What do SBs do in suspension link usage that rubber and poly bushing do not do? If SBs meet the definition of a bushing and if they are made of a material alternate to the original bushings and if they perform only the functions of original bushings but in a significantly improved manner - is it their improved function that makes them illegal? That can't be the objection.

That is not central to my argument (see above). If the rule read "bushings are unrestricted" rather than "bushing material...is unrestricted" and you can make a reasonable argument that spherical bearings are bushings, then you'd have a leg to stand on.

You have said that SBs are not bushings. So even if I make the argument, which I have, that they are bushings then you still would not deem them legal even if bushings were unrestricted. Am I mistaken in my understanding that you do not view SBs as bushings?

If you were to agree that SBs are bushings then they would be bushings of an alternate material as I have stated. Whether bushings or bushing materials are unrestricted - such language wouldn't matter. In either wording whether or not the reader believes SBs are bushings would result in the same conclusion on legality in both wordings.

SBs are bushings - both wordings make them legal.

SBs are not bushings - both wordings absent specific mention of SBs make them illegal.

My argument that they are bushings has the same leg to stand on whether it is bushings or bushing material that is unrestrected.

PS whether I spend money on them or not is not relevant - just as whether they have been used in perpetuity is not relevant (an argument I have NEVER made not that you said I had). If they are illegal they are illegal - technically I spent money on the short shifter I removed when I bought the car - I still removed it even though I spent money on it just as I had spent money on everything else installed on (or removed from) the car. I spent considerable time and money making damn sure the car (with a 9 year history in the log book and several ARRCs and not less than a few ARRC tear downs) was legal and that I lose my races legally and based on my lack of driving skill.

**Greg Amy** · 01-07-2006, 11:06 PM

Ed, you're makin' my head spin. As simply put as I possibly can:

If your suspension bushings differ from stock in any way other than the substance of which they were originally made, they are illegal.

Greg

**ddewhurst** · 01-07-2006, 11:06 PM

Posted by Dick

***My assumption is that if I gave up the bearings the bind would return but now that I think about it I have never run the car with the tri link and a stock style lower link bushing so I am not sure. Have you.***

Posted by Jake

***But the lower longitudinal arms locating the axle are the "issue".***

Dick & Jake, with my 1st gen RX-7 when I implemented the Tri-link (added), implemented OEM upper links with foam bushings (bushing material unrestricted) I also implemented lower links (subsitituted) made of male Heim joints (Spherical bearings) & steel tie rods. ALL ALLOWABLE & LEGAL because of the rule 17.1.4.D.5.c.1. added or subsitituted traction bars, Panhard rod or Watts linkage. I agree with Greg on the unrestricted bushing material rule & if someone had a desire to protest my lower links please have at it.

Because my lower link bushings (spherical bearings) are allowed by a seperate rule as stated above.

Yes, using the Tri-link with foam bushings in the upper links & OEM bushings in the lower links there would be an effect of binding with the lower link OEM bushings as the chassis rolled but not nearly as great of bind as with all four links with OEM bushings. Also the upper links length is angled maybe 3 inches inward at the front mounting compared to the rear mounting position causing bind.

Posted by Andy

***I would think that without SB 'technology' as bushings, a car with a certain type of suspension would develop binding when lowered beyond "X" point. Bushings of alternate MATERIAL ONLY, would not fix this. Bushings of any material and design, would.***

Andy, that's the fun part of rule 17.1.4.D.5.d.6. unrestricted material & 17.1.4.D.5.c.1. added or subsitituted traction bars, Panhard rod or Watts linkage allows bushings of any material and design for the 1st gen RX-7.

:P :P Dick is ok with spherical bearings in his 1st gen RX-7 lower links.

ps: If you folks have not seen the movie "Rummor has it", take your other & see it.

**turboICE** · 01-07-2006, 11:20 PM

Originally posted by GregAmy@Jan 7 2006, 11:06 PM
If your suspension bushings differ from stock in any way other than the substance of which they were originally made, they are illegal.
[snapback]70389[/snapback]

They don't (in all 28 links just in the rear) so all is good.

**theenico** · 01-08-2006, 02:42 AM

At some point someone asked for input.

I vote for spherical bearings/bushings (does the teflon liner make them more like a bushing ?

).

I like them because they last forever and help the car respond consistently.

**dickita15** · 01-08-2006, 08:04 AM

Originally posted by ddewhurst@Jan 7 2006, 11:06 PM
Dick & Jake, with my 1st gen RX-7 when I implemented the Tri-link (added), implemented OEM upper links with foam bushings (bushing material unrestricted) I also implemented lower links (subsitituted) made of male Heim joints (Spherical bearings) & steel tie rods. ALL ALLOWABLE & LEGAL because of the rule 17.1.4.D.5.c.1. added or subsitituted traction bars, Panhard rod or Watts linkage. I agree with Greg on the unrestricted bushing material rule & if someone had a desire to protest my lower links please have at it. Because my lower link bushings (spherical bearings) are allowed by a seperate rule as stated above.

[snapback]70390[/snapback]

david, that interpretation revolves around the lower control arms be defined as a traction control bar. I would not bet the bank on it going that way.

**dickita15** · 01-08-2006, 08:42 AM

Originally posted by GregAmy@Jan 7 2006, 11:06 PM
If your suspension bushings differ from stock in any way other than the substance of which they were originally made, they are illegal.
Greg

[snapback]70389[/snapback]

There in lies my problem with your position Greg now that you have stated it in the simplest terms. Any change in material will bring with it other changes in some other way, whether that is function compliance or even appearance. Your statement is very definantive.

The fact the words “bushing material” rather than “bushing” is used is relevant and I think that it prevent us from changing the dimensions of the bushing as in the case someone sited before about subframe mounts.

By the way my previous comments about the effect on my car of changing this 10 year old interpretation are not germane and were added as a throw away line. I am sorry if that detracted from the more serious discussion.

**ddewhurst** · 01-08-2006, 10:47 AM

***david, that interpretation revolves around the lower control arms be defined as a traction control bar. I would not bet the bank on it going that way.***

Dick, if the lower links are not traction bars the manufacture would have eliminated them in a cost savings effort because one set of links at the vertical center of the rear axle would provide longitude location. The workshop manual refers to them as upper & lower links. Remove one set of links & see how much traction you have.

What hypothesis have the third link manfactures used to add the third link ?

Rule 17.1.4.D.5.c.1. allows added or subsitituted traction bars, Panhard rod or Watts linkage. We know the third link is not a Panhard rod or a Watts linkage which leaves us with the third choice to call the third link. The third link is an added traction bar. If the upper links are traction bars then the lower links are also traction bars. Counter point please...............

**Geo** · 01-08-2006, 10:59 AM

Originally posted by GregAmy@Jan 7 2006, 08:06 PM
If your suspension bushings differ from stock in any way other than the substance of which they were originally made, they are illegal.

[snapback]70389[/snapback]

That would render a great many aftermarket bushings illegal.

I personally think that would be an onerous rule. Bushings that are not solid (such as the trailing front lower control arm bushing on an NX2000) would take some serious effort to reproduce. Probably a lot more cost than SBs.

**dickita15** · 01-08-2006, 11:03 AM

David,
We agree that the third link is a traction bar. But you are suggesting all 4 stock links are as well. I can see you point but if that were true would it not be generally accepted that you could just remove the upper links instead of rendering them inoperative with foam and leaving them in place.

I think that we are on the same page in that it all depends on the stock links being defined as traction bars. They seem to meet the glossary definition of both traction bars and trailing links.

**Greg Amy** · 01-08-2006, 12:24 PM

Dick, I'm a bit confused; I agree with what you're saying but I think we still disagree on the main result. I want to reorganize your points a little bit...

Originally posted by dickita15
The fact the words “bushing material” rather than “bushing” is used is relevant...

I absolutely, positively, completely agree; it's what I've written several times and is the main point of my argument. If the rule stated "bushings are free" then we'd have no disagreements.

I was tempted to try one of my old Elementary School sentence structure breakdowns, but I figured that would rile the troops even more. Needless to say, I believe that the word "unrestricted" is the object of the word "material", not the word "bushing". I further suspect that many of those that disagree with me believe the word "unrestricted" is the object of the word "bushing"; that is incorrect.

Thus, the material is free; nothing else.

Originally posted by dickita+--><div class='quotetop'>QUOTE(dickita)</div>

I think that (the words “bushing material” rather than “bushing”) prevent us from changing the dimensions of the bushing as in the case someone cited before about subframe mounts.[/b]

I agree. So, if that's the case, are you arguing that a conversion to spherical bearings from rubber bushings is NOT a change in dimensions...? If that's what you're saying, then there's the core of our differences: I don't see how any person can reasonably argue that there is no dimensional differences between a rubber bushing and a spherical bearing; they're just two totally different animals, FAR and above a simple change in 'what they are made of'.

<!--QuoteBegin-dickita
Any change in material will bring with it other changes in some other way, whether that is function compliance or even appearance.

I again agree with you, however exploiting that change to a degree such as you describe in regards to spherical bearings is the whole reason we have the "tortured interpretations" and "unintended function" clauses in our rules.

Originally posted by Geo
I personally think that would be an onerous rule (re: limiting dimensions).

But, George, isn't that the way the rule reads? If you believe that an allowance (or restriction) in material allows (or restricts) dimensional changes as well, why did you - as part of the current ITAC - recommend the following words in ITCS 17.1.4.C in regards to aftermarket replacement parts? Why qualify the difference if there is none?

It is not intended to allow parts that do not meet all dimensional and material specifications of new parts from the manufacturer.

I believe the ITAC/CRB mentions both material and dimensional because they believe - as I do - that there is a distinct difference. Given that, the implication vis-a-vis suspension bushings is clear.

GregA

**dickita15** · 01-08-2006, 12:44 PM

Originally posted by GregAmy+Jan 8 2006, 12:24 PM-->

I agree. So, if that's the case, are you arguing that a conversion to spherical bearings from rubber bushings is NOT a change in dimensions...? If that's what you're saying, then there's the core of our differences: I don't see how any person can reasonably argue that there is no dimensional differences between a rubber bushing and a spherical bearing; they're just two totally different animals, FAR and above a simple change in 'what they are made of'.

[snapback]70406[/snapback]
[/b]

Well that is what I am saying. In my case, and I have not worked on enough different types of IT cars to know how this affects other, the bearing cartridge in my car is the same od, the same id and the same length as the stock ones I replace. It requires no modification of the stock parts and located the stock part in the same way as the stock bushing. Does it change the range of motion because of this material change? Of course.

Now I know if you accept this the next argument that will be made is that some of the material can be replace with air but that is not my argument.

<!--QuoteBegin-GregAmy@Jan 8 2006, 12:24 PM
But, George, isn't that the way the rule reads? If you believe that an allowance (or restriction) in material allows (or restricts) dimensional changes as well, why did you - as part of the current ITAC - recommend the following words in ITCS 17.1.4.C in regards to aftermarket replacement parts? Why qualify the difference if there is none?

It is not intended to allow parts that do not meet all dimensional and material specifications of new parts from the manufacturer.

I believe the ITAC/CRB mentions both material and dimensional because they believe - as I do - that there is a distinct difference. Given that, the implication vis-a-vis suspension bushings is clear.

GregA

[snapback]70406[/snapback]

Greg, now I think maybe you can be accused of the use of red herrings. Just because in today’s climate the ITAC wants to be more specific in language in order to be more clear does not cause a change in existing rules.

**Bill Miller** · 01-08-2006, 01:07 PM

I again agree with you, however exploiting that change to a degree such as you describe in regards to spherical bearings is the whole reason we have the "tortured interpretations" and "unintended function" clauses in our rules.

And there's the rub Greg. Kirk's pointed it out before, where do you draw the line, in terms of 'exploiting the change' in design, before if becomes illegal?

I'm still trying to figure out where that line is, with you. Is it when you reduce the friction coefficient to a ceratin level? I'll go back to my VW example. You said (at least I think it was you, maybe it was Andy), that a bearing cassette, used in place of the front and rear control arm bushings, would not be legal. But if I used something similar to the 'polybronze' bushing that Jake mentioned, would I then be legal? Neither one provides any out-of-axis motion, and both would probably provide the same level of reduced friction coefficent. Both are clearly different designs than a stock bushing. You used to race one of these cars Greg, you know what I'm talking about.

If you're going to hang your hat on the design change criteria, how do you say that it's ok to exploit the design change of a solid bushing (and I would say that eliminating deflection is a pretty significant exploitation of that change), but not ok to exploit the design change of a spherical bearing, as it not only eliminates deflection, but also reduces the rotational friction coefficient?

**Dave Zaslow** · 01-08-2006, 01:21 PM

This is indeed a most ineresting debate. Now I can show my ignorance

The OEM bushing allows compliance in three dimensions, x, y, and z. Changing the material to a solid metal must lead to zero deflection in at least two dimensions, most probably until the pickup point is ripped out of the car. Making them from delrin does the same to a slightly lesser degree. This is done in the name of improved transient response as well as eliminating or reducing unwanted suspension movement.

Going back to Kirk's pictures of some OEM VW control arm bushings, they allow all three dimensions of deflection.

Now compare these to the attached photo (from Shine Racing) of their spherical bearings for the same purpose. Both Shine pieces allow two dimensions of movement.

I think we can agree that all of the bushings/bearings we are talking about do not relocate suspension pickup points or geometry. Indeed I think the points made above regarding the difference in IT vs. Production rules are good ones. Adjustable spherical bearings are a whole 'nother animal.

So is a bushing a bearing?

Let's look at some glossary definitions again:

"Bearing - A mechanical component provided to allow connected parts to
move with respect to one another in a manner consistent with durability
and minimal friction."

Certainly this describes the bushings we are discussing.

"Bearing Carrier - A housing in which the bearings carrying a shaft are
mounted."

Again using Kirk's photos, we have rubber bonded to metal in a one piece design. Most 'high performance' replacements are two or three piece designs that do not need to be pressed in to their respective holes. This

"Bushing/Bush - A sleeve or tubular insert, whose purpose is to reduce the
dimension(s) of an existing hole."

Every piece described, OEM or not, does this. If its non-OEM construction is of differing design, including multiple pieces rather than one piece, it is of debatable legality.

"Spherical Bearing - A load-bearing connector in which the central portion
is convex and the outer portion is concave, allowing both angular
displacements of the axes and relative rotation."

This seems not to perform any function different than that of the three piece bushings we are conjecturing are perfectly legal to use.

So I posit a bushing must be a bearing, although a bearing may not be a bushing.

Dave Zaslow

Feeling very bush league amongst this learned group.

Thread: Spherical "Bushings"

Thread Tools

Search Thread

Display

Bookmarks

Bookmarks

Posting Permissions