Spherical "Bushings"

[Greg Amy]

As you are on doubt aware, the use of spherical bearings is a pet peeve of mine. To this very moment I am unconvinced that these items meet either the spirit or the letter of the rules.

So, really, why do we accept these things legal for Improved Touring?

Spherical bearings as suspension bushings are something that has been generally - and, I think, grudgingly - accepted in IT for a while. I do not know who did it first, or whether it went through any kind of approval process, but I strongly suspect that this may be a result of an "acceptance" mindset where 'it hasn't been protested so it must be legal' or 'that guy is doing it, so it must be legal'. I've heard rumors that someone sent a letter or email to the then-SCCA Technical Manager Sven Pruett and got a thumbs-up for it (but have never seen it). Regardless, as we all know a letter/email interpretation/approval from Sven Pruett (or Jeremy Thoennes) does not carry the weight of legality, it is simply an opinion, one that can easily change with the person occupying the staff position. It certainly does not carry the weight of a GCR 13.9 Rules Interpretation. I further suspect that based on this acceptance/approval more and more folks have been taking it as gospel that it's legal.

It would surprise no one to find that I strongly disagree. Let's talk about the referenced rule. It states,

Bushing material, including that used to mount a suspension subframe to the chassis, is unrestricted.

Consider that in Improved Touring one cannot change anything unless specifically allowed, our standard IIDSYCYC ("if it doesn't say you can, you cannot".) Also consider that any part has multiple characteristics; these include primarily dimensional characteristics and material characteristics. This particular rule does not state that "bushings are unrestricted"; in point of fact, it specifically states that "Bushing material...is unrestricted". Given this, where does one find the supporting basis for changing the dimensional characteristics of suspension bushings? Where does one find the supporting basis for replacing solid bushings with spherical bearings?

So I ask again:why do we accept these things legal for Improved Touring? Just 'cause we want 'em? Not good enough.

It bothers me enough that I am planning on doing something about this in 2006. Because it is cheaper than a GCR 13.9 ($25 versus a $250 sunk cost), I am going to file a protest against a competitor - picked at random? - that is running spherical bushings in their suspension. I will file this protest with the hope that the competitor will lose and be forced to appeal to National for a final ruling. If my protest is denied, then I myself will file an appeal to National.

Note that new in the '06 GCR in 13.6 is the verbiage, "A non-compliant ruling will be published; a compliant ruling will not be published." I will accept the results of the appeal(s) as de facto and dejure evidence of the legality of the rule.

I sincerely hope to do this in a non-confrontational way by finding someone willing to work with me, but I sinerely doubt that will happen. However, if you're interested in working with me, please let me know.

In the meantime, feel free to debate the rule here. See if you can make a reasonable, cogent, logical argument - without referring back to "that's the way it's been" - as to why spherical bushings are allowed in Improved Touring. - GA

[Bill Miller]

Greg,

I thought that earlier in '05, there was a ruling in FasTrack, about spherical bearings being allowed. I just looked (briefly) through the '06 ITCS, and didn't see anything about it, other than the passage that you cited.

I'm inclined to agree with you, that they are beyond the scope of both the purpose, and the intent of IT racing. But, as I've said before, it seems that the PP&I (Philosophy, Purpose, and Intent) only get trotted out on occasion, and are not applied evenly. That being said, I think that things are probably a bit too far down the road, at this point in time, to take them away. And the only end that it would serve, would be to, ever so slightly, improve the alignment w/ the PP&I. Being as things are so far afield of the PP&I now, I really don't see the need to worry about it.

And that ladies and gentlemen, is EXACTLY how rules creep works!

[Andy Bettencourt]

Greg,

You can protest me this year - if you think it will work. Here is why I say that:

I do believe spherical bearings (SB's) as bushing's are not allowed as the rulebook reads. As you state, the rules say that bushing material is unrestricted. So I then go to the glossery and look up the defenition of bushing:

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

While a SB does this, it ALSO does much more (pivoting on virtually unlimited axis&#39. So I submit that they would be illegal under the 'an allowed modification can not perform a prohibited function'

So - my car will have offest bushings in the control arms in order to attain more negative camber than the stock range permitted by D.5.d.2 (the installation of eccentric bushings). I believe I am legal - do you think this crosses the line of 'changing the dimensional characteristics of suspension bushings?' An example can be seen here:


AB

[Greg Amy]

Originally posted by Andy Bettencourt@Jan 4 2006, 11:27 AM
I believe I am legal - do you think this crosses the line...

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Absent any other rule, I would consider this to be illegal. However,

17.1.4.D.5.d.2, "On other forms of suspension, camber adjustment may be achieved by the use of shims and/or eccentric bushings."

[JeffYoung]

I agree. It also seems to me that under some formulations of the thinking allowing SBs, you can do some things that are in my view illegal, or at least not intended by the rules.

For example, as Greg points out:

Bushing material, including that used to mount a suspension subframe to the chassis, is unrestricted.

Greg then goes on to say:

Consider that in Improved Touring one cannot change anything unless specifically allowed, our standard IIDSYCYC ("if it doesn't say you can, you cannot".) Also consider that any part has multiple characteristics; these include primarily dimensional characteristics and material characteristics. This particular rule does not state that "bushings are unrestricted"; in point of fact, it specifically states that "Bushing material...is unrestricted". Given this, where does one find the supporting basis for changing the dimensional characteristics of suspension bushings? Where does one find the supporting basis for replacing solid bushings with spherical bearings?

Since the "material" used isn't, under the line of thinking allowing SBs, dimensionally limited, what is to prevent me from making a 3" block of urethane as my "bushing" between the subframe and chassis when the stock bushing is only 1" thick?

This drops the subframe and motor lower in the car, lowers the CG, etc. and appears "legal" under the SB way of thinking.

Also, by making a suspension point pivot, as opposed to a static mounting, aren't you effectively changing a mounting point? The suspension piece attached to the SB will certainly load differently as it moves through the range of motion allowed by the SB (and that would not be present with a standard bushing).

I'm fairly new to IT but this is one of those things that really jumped out as a "huh? that's legal?" Up there with the no coil overs unless you use a threaded collar on the shock....which I know has know has been changed.

[Ron Earp]

Can someone post a picture of what we are talking about here with spherical bushings?

Do you mean heim (rose for UK folks) joint? Man, that would require some serious modification to fit and would not be legal for sure.

Ron

[handfulz28]

Look at remote resevoir shocks, is that not an example of taking something back? It can be done.

Exactly what are the "dimenional characteristics" of a suspension bushing? I'd say geometry and design dictate those, not material. Different materials permit varying amounts of compliance with design, so IMHO, a spherical does not add anything not previously designed in.
What types of solid bushings are being replaced with sphericals?

If we accept that the rubber material is unrestricted, we substitute the rubber with metal, while the metal takes in some instances a different shape, it does not perform a prohibited function.

Perhaps there are some installations where a spherical bearing allows something more than was designed (materials not withstanding), but I'm confident that in my installation, my metal bushings only serve the PURPOSE to allow the suspension geometry to perform to its design INTENT.

Thanks,
Michael
SEDIV ITA 240SX

[ddewhurst]

***Can someone post a picture of what we are talking about here with spherical bushings?***

Ron, you use the words spherical BUSHINGS. The conversation is about spherical BEARINGS.

A Heim joint has a male or female thread attached to the outer race. A spherical bearing/mono-ball has no male/female thread attached to the outer race. The outer race of a spherical bearing slip or press fits into another piece.

Example, where Andy is using his ecentric bushing he could if he chose use a spherical bearing IF it were legal. If he chose to use a sprerical bearing he in simple terms would loose his camber adjustment. I don't know what Andy's control arm looks like but he could also modify the inboard end of the control arm, & use a Heim joint with a pair of nuts & then he would have his some radial freedom & his adjustment for camber. Not legal IMHU of the rules.

[kthomas]

Protest me. This is BS. I'm willing to bet they find the intent of replacing suspension bushings is so that one can properly, and consistently locate suspension members. If you need a rule that says spherical bearings for said purpose are legal then maybe a protest will get them to clarify, but a phone call to Topeka would be easier....

And for the record- the banning of remote reservior shocks was a tax on rich people to make "have-nots" feel better. Nothing else.

[Andy Bettencourt]

Originally posted by handfulz28@Jan 4 2006, 01:32 PM
Look at remote resevoir shocks, is that not an example of taking something back? It can be done.

Exactly what are the "dimenional characteristics" of a suspension bushing? I'd say geometry and design dictate those, not material. Different materials permit varying amounts of compliance with design, so IMHO, a spherical does not add anything not previously designed in.
What types of solid bushings are being replaced with sphericals?

If we accept that the rubber material is unrestricted, we substitute the rubber with metal, while the metal takes in some instances a different shape, it does not perform a prohibited function.

Perhaps there are some installations where a spherical bearing allows something more than was designed (materials not withstanding), but I'm confident that in my installation, my metal bushings only serve the PURPOSE to allow the suspension geometry to perform to its design INTENT.

Thanks,
Michael
SEDIV ITA 240SX

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Michael,

I agree with what you are saying - to a point. Metal bushings are ok in my mind, but a SB - as a bushing - allows the mounted piece to pivot in ways that the stock - or replacement of different material - can not. So I do not believe it fits the definition of a bushing in the GCR because it works outside the stock range of functionality.

And we aren't debating putting this back in the box, just clarifying interpretations of an existing rule (see the piston thread).

AB

[ddewhurst]

When we look up the words bushing & bearing in the GCR glossary I would think we can agree that a bearing allows movement with minimal friction & that a bushing by the nature of the beast will not allow movement with minimal friction. With a bushing we must displace the bushing material to gain angular rotation.

Thoughts ?

Just trying to communicate on the subject towards Greg's question.


***but a phone call to Topeka would be easier....***

A phone call to Topeka or the $250.00 deal is NOT the final word on rules.

[Knestis]

I'm having trouble with this one, I confess...

For example, in what kind of application could a spherical bearing provide motion that wasn't already allowed by flexion of the OE material?

We had this conversation here a few years back and, after the dust settled, I admit that i had got to the point where I couldn't find a bright line anywhere between "must be stock" and "spherical bearings," looking just at the logic and attributes of the parts involved.

If you can change the material, it's - as far as i can tell - necessary that changes in dimensions be allowed, too. Am I wrong?

Short of writing a dissertation about the different types of bushing (there are two different ones in each of my Golf A-arms), and what can and cannot be changed, how would the interpretive distinction be made, to allow dimensional differences, multi-material options (e.g, urethane-only vs. rubber-on-metal), or design differences short of "spherical-ness" without crossing the line?

K

EDIT - the GCR glossary def of "bushing" is also problematic. The rear "bushing" on my A-arms is a rubber donut, with a steel sleeve in the middle, and a metal ring around the periphery. It presses into the arm, and a bolt goes vertically through its middle, through the subframe and into the chassis. By the strict definition, it's NOT a bushing, becuase the absolutely necessary flexion of the part is a "purpose" beyond that described by the definition ("to reduce the dimension(s) of an existing hole") - so I can't change it? Is that the intent?

[joeg]

What does this mean to all of us who have spherical bearings in the camber plates for their struts?

While I cannot get that excited about this, I believe a lot of this goes back to RX7 rear suspension work...from a historical perspective.

[erlrich]

Originally posted by rlearp@Jan 4 2006, 02:01 PM
Can someone post a picture of what we are talking about here with spherical bushings?

Do you mean heim (rose for UK folks) joint? Man, that would require some serious modification to fit and would not be legal for sure.

Ron

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Ron - here are some examples; the top photo is a simple spherical bearing, followed by a few examples of types of control arm bushings available for my 240SX. They are, in order, a Nismo high-durometer rubber bushing (nearly identical to the stock bushing), SPL Parts spherical bushings, and Whiteline polyurethane bushings.

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The biggest problem I see with the whole "dimensional characteristic" argument is that if you look at the poly bushings, which nobody seems to have a problem with, they are least like the OEM bushings dimensionally (IMHO).

Also, Andy's comment about the spherical bearing allowing for movement outside the range of other bushings makes sense at first, but then when you consider that all bushings allow for some movement outside of the primary axis (isn't that what the rubber is there for?), it becomes a question of whether the spherical bearing is doing something the others can't, or just does the same thing that much better.

I personally wouldn't mind seeing this protest upheld, it would save me about a grand in build costs, but I think you're peeing into the wind on this one (again, JMHO )

edit: I have to clarify my comment about the poly bushings; in the photo I used here the assembled poly unit would not be all that dissimilar to the OEM unit. However, many of the poly bushings (including the ones for the rear of my 240) do not use the outer sleeve, instead the poly bushing presses directly into the bare control arm. This is what I was referring to. Sorry.

[Ron Earp]

Originally posted by ddewhurst@Jan 4 2006, 02:39 PM
***Can someone post a picture of what we are talking about here with spherical bushings?***

Ron, you use the words spherical BUSHINGS. The conversation is about spherical BEARINGS.

A Heim joint has a male or female thread attached to the outer race. A spherical bearing/mono-ball has no male/female thread attached to the outer race. The outer race of a spherical bearing slip or press fits into another piece.

I suppose what I am asking is the following - is a spherical bearing placed inside the tube where the rubber bushing would have been? Maybe a nice picture of a spherical bearing/bushing or whatever you wish to call it would be worth 1000 words.

I know what a heim joint is and I suppose I've got this picture in my mind of people somehow putting the the working parts of a heim joint, the ball and race, into their control arm holes? Is this correct?

Ron

[Andy Bettencourt]

Originally posted by Knestis@Jan 4 2006, 02:23 PM
I'm having trouble with this one, I confess...

For example, in what kind of application could a spherical bearing provide motion that wasn't already allowed by flexion of the OE material?

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Sway bar end links.



Lower control arms. This allows the car to be lowered beyond what the stock geometry would permit given 'fixed' bushings.



AB

[dickita15]

Originally posted by Andy Bettencourt@Jan 4 2006, 12:27 PM
So I then go to the glossery and look up the defenition of bushing:

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

While a SB does this, it ALSO does much more (pivoting on virtually unlimited axis&#39. So I submit that they would be illegal under the 'an allowed modification can not perform a prohibited function'

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I understand Greg that you do not think this should have happened but refering to the definition why can't my sleve or tubular insert be a cartridge of a bearing with a metal shell that replaces the original metal and rubber cartridge.

By the way my sperical cartridge allows the same or less pivoting that the foam bushing i use.

then i need to know where it says that "pivoting on virtually unlimitied axis" is a prohibited function.

[Andy Bettencourt]

Originally posted by dickita15@Jan 4 2006, 02:46 PM

then i need to know where it says that "pivoting on virtually unlimitied axis" is a prohibited function.

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You quoted me on this but Greg may answer anyway.

Dick - that point is one I had issues with as well in my thought process in this debate. How about this:

The use of a SB as a bushing allows for and performs funtions not originally intended.

If your fuel lines are free, are you allowed to have an in-line 1-gallon 'tank' that you may use excusivly for qualifying - or as extra gas for enduros? Probably a poor example but...

I think the point that people are polarized on is the definition of the bushing. I read the function in the definition and I beleive the SB as bushings to go beyond that definition in terms of functionality.

No real benfit in my car because there is limited (if any) bind in a double wishbone suspension as you lower the car. The Gen 1 RX-7 and the 240SX's come to mind in cars where this would be very prevelent.

Again, this is a simple debate. I don't see that much of a benefit to getting them outlawed...just silly season talk. Greg may have other motivation, I do not know.

AB

[handfulz28]

Katman, interesting point of view. No agreeing or disagreeing, but it still serves as an example where a rule change required a significant change.

Andy-I guess that's where part of the disagreement with the use of SBs stems from. If you accept that at least part of an OEM suspension bushing's purpose is to limit suspension movement, then you'll have a hard time with SBs.

I think you have to reasonably accept that's not their purpose, but instead a result of material dexterity, or lack thereof.

I'll try to use an example from my car (ITA 240SX): front lower ctrl arm. The inboard mounting point (MP) is a bolt/bushing running in the longitudinal axis of the car, plus or minus some fudge for caster/camber/toe, providing for a nearly vertical single axis of movement. Connected (by fixed bolts) to the ctrl arm near the outboard end is a tie rod, fixed at an approx angle of 45 degrees, said rod being connected to a forward MP using a bolt/bushing, aligned such that the tie rod also rotates through an approx vertical single axis.

Now it's been awhile since I've practiced my analytical geometry, but would you agree that at a static point, the OEM rubber bushings are not deflected in any way? But as the connected suspension pieces move throughout a range of motion, said pieces are limited in their movement by the compliance of the rubber, not by their design or geometry. In fact, wouldn't you agree that the very design and geometry REQUIRES movement outside of the single axis plane, and therefore compliance at the MP/bolt/bushing of multiple planes/axis'?

In this installation, a spherical bushing simply allows a bit more compliance for the suspension assembly to move throughout its designed range. No MPs have been relocated, nothing moves that didn't move before, nothing is fixed that wasn't fixed prior.

Thanks,
Michael

[ddewhurst]

***By the way my sperical cartridge allows the same or less pivoting that the foam bushing i use.***

Dick, most times when we talk about foam it has to do with beer. If you are refering to the foam bushings in the rear of 1st gen RX-7 the rule that allows foam bushings is rule 14.1.4.D.5.c.1. Any anti-roll bar(s), traction bar(s), panhard rod or watts linkage may be added or substituted, bla bla bla. The word ANY being key. Kind of the same as the word alternate.

To others, if I were to protest someone who had used the rule "Bushing material, including that used to mount a suspension subframe to the chassis, is unrestricted" I would open the GCR glossary to the definition of bearing & bushing, then I would with my fingers rotate the inner race of the spherical bearing relative to the outter race of the spherical bearing with MINIMAL FRICTION (words from the GCR glossary) & everone would see/feel MINIMAL FRICTION. Then I would ATTEMPT to with my fingers rotate the inner race of the bushing (rubber/metal) to the outter race of the bushing & all would see/feel that the rotation angle did not change with MINIMAL FRICTION. The key is the words MINIMAL FRICTION in the GCR glossary with the definition of bearing.