Spherical "Bushings"

[turboICE]

Machinery's Handbook defines a bushing as a tooling component used for locating drill bits quickly. A bearing, on the other hand, is a machine element that allows movement between two parts. What you have been refering to as a bushing is know as a "plain bearing". Food for thought.
[/b]

It has been brought up before in this and other threads. I come at its legality with a similar view. A valid position can be taken in opposition that when the GRC defines terms in the glossary those are its intended definition.

Though when I look at suspension bushing I believe their wording is the same as a bearing's definition.

 

[Bildon]

>> I think what Tristan was alluding to is what's the point you are trying to make?

Same thng I asked about 10 pages back.
While they go on and on, people keep building, selling and racing cars with spherical bearings.

Hey Tristan, long time no see...how are ya!
Might get to VIR this year, you?

 

[turboICE]

Greg,

Instead of railing aginst spherical bearings, what you need is a better way to lower. I'm sure you know about lowering spindles. Another option would be to lift the lower mounting point up, like a longer ball joint or even a spherical bearing with a longer tapered shaft to replace your stock ball joint. You won't even have to modify your stock lower arm, making it perfectly legal, and you get to keep better goemetry.

James

ps. I've got McP struts on the front and trailing arms rear. The only stock adjustment on my car is front toe, so much for a perfromance alignment for stock class auto-crossing.
[/b]

I don't think his objection relates to his own car's inability to lower further and seeking to prevent others from doing so, I disagree with him but see his objection as an unselfish interpretation of how he honestly sees the rule. At least based on my interactions with him.

 

[Andy Bettencourt]

Greg,

Instead of railing aginst spherical bearings, what you need is a better way to lower. I'm sure you know about lowering spindles. Another option would be to lift the lower mounting point up, like a longer ball joint or even a spherical bearing with a longer tapered shaft to replace your stock ball joint. You won't even have to modify your stock lower arm, making it perfectly legal, and you get to keep better goemetry.

James

ps. I've got McP struts on the front and trailing arms rear. The only stock adjustment on my car is front toe, so much for a perfromance alignment for stock class auto-crossing.
[/b]

James,

Help me out - where in the rules are any ball-joint modifications/substitutions legal?

 

[erlrich]

Greg,

Instead of railing aginst spherical bearings, what you need is a better way to lower.
[/b]

Ahhhh, now I see. And here all this time I thought Greg was acting upon some deep-seeded desire to maintain the purity of the class (philosophically speaking of course, I know in fact we're all just a bunch of mutts) by preventing the influx of true racing paraphernalia into an environment where it was never intended. Now I learn that his real motive stems from his suspension inadequacies.

Nothing to be ashamed of Greg, it happens to all of us at some point, and I'm sorry to have to tell you it gets worse as we get older

 

[tderonne]

James,

Help me out - where in the rules are any ball-joint modifications/substitutions legal?
[/b]

On any car where the ball joint attaches to the strut housing, "any" strut housing being legal of course. Like the RX7, 510, 240Z, etc.

(Biggest inequity in IT suspension rules if you ask me.)

 

[Greg Amy]

Now I learn that his real motive stems from his suspension inadequacies....[/b]

No, no, no, no, NO; you misinterpret. I simply brought that up as a cynical counterpoint to Tristan's position, that SBs *must* be allowed in order to maintain a theoretical parity in the class. His implication was that his car was classed with the use of SBs in mind to "cure" his suspension inadequacy; my "winky-winky" point was that since I also have a suspension inadequacy it was only fair to adjust the rules accordingly for me, too...said differently, my point is that we must all work within the rules and make compromises for our shortcomings, and not expect the rules to be adjusted to address these issues individually.

Trust me, my position is pure as the driven...well, this year it's been all mud around here...hmmmmm....

Originally posted by Z3_GoCar
Instead of railing aginst spherical bearings, what you need is a better way to lower. I'm sure you know about lowering spindles...

The problem, James, is that this is very much dependant on the design of the car. The *vast* majority of cars out there do not have spindles integral to the strut.

Look at Ed's illustration above: that's what the majority of cars look like, especially anything built within the last twenty years or so based on an econobox. You'll notice that there are discrete parts of control arm with ball joint, knuckle with pressed-in bearing and hub, and McPherson strut. They are built this way to be modular in terms of production, and to be much easier and less expensive to repair/replace in case of an accident. In this case the strut is decisively separate from the spindle/ball joint, and to make any mods to the knuckle and/or ball joint would be illegal under the Improved Touring rules. My car, for example, has this same design on all four corners and there is no legal way to favorably change my geometry (unless you guys support spacing out the ball joints from the knuckle...)

For a really nice example to the contrary, take a look at Alan Lorenco's ITB Audi Coupe (anoyne got any photos?). The Coupe has the strut and knuckle as one complete part, with the ball joint integral at the bottom. Strut is free, right? In Alan's case, Dick Shine has built a B-E-A-U-T-I-F-U-L strut assembly that completely corrects any undesireable geometry issues. It's an absolute work of ART and when I got a good eyeful of it I knew that this was probably the future of the class - along with the B-E-A-U-T-I-F-U-L rear suspension work on Curran's ITB Volvo. Neither of these cars have ANY deviant suspension problems and can lower their cars to the absolute minimum ride height and not worry about it.

Yep, I would strongly agree it's a significant inequity within the rules, but it's perfectly legal. I can only assume such technical inequities are addressed via the new PCA process; as an example I get 80 pounds under the Acuras due to my suspension design (I'd rather have the suspension...) - GA

 

[erlrich]

No, no, no, no, NO; you misinterpret. [/b]

Sorry Greg, I forgot to put the little after my comments. I was just messin with you man

 

[turboICE]

I can only assume such technical inequities are addressed via the new PCA process; as an example I get 80 pounds under the Acuras due to my suspension design (I'd rather have the suspension...) - GA
[/b]

OK now I am totally confused - I coulda sworn that you and Andy just told me that geometry advantages/disadvantages due to specific suspension limitations and ability to lower or not aren't to be addressed within the process!

The other topic -

From here: http://e30m3performance.com/tech_articles/..._comp/index.htm

Is this what you mean with your issue: "As the car is lowered and the control arms attain a sloping upwards position, the gain in camber as the suspension compresses becomes less and less. To the point where there can be little to no negative camber gain whatsoever when the car leans in a corner. This means that every degree of chassis roll is directly translated to a degree loss in negative camber, and this occurs precisely when you need that negative camber on the outside front wheel the most - during cornering."

Could it be with my front McP suspension and also lacking the ability to make the type of modification they discuss that my running higher negative static camber is compensating for the effect? Would more negative static camber allow you to lower further before the detrimental RC/CG spread overcame your static camber?

As I lowered the car incrementally, the only way the lap times improved were with incrementally more static negative camber in front in conjunction with it. For even tire contact on a course like SP or VIR I run as much a -3.5* static.

I guess I am trying to redeem this thread by coming up with stuff I can learn from it.

 

[Andy Bettencourt]

PCA's are "Post" classification adjustments or "Performance Compensation Adjustments", to be used in extreme cases per the ITCS. Chassis inequities are addressed at the time of initial classficiation/reclassification.

So Ed is right, but Greg is right in that the difference in weight of the NX and the Teg are primarily due to the suspension set-ups.

AB

 

[turboICE]

As I lowered the car incrementally, the only way the lap times improved were with incrementally more static negative camber in front in conjunction with it. For even tire contact on a course like SP or VIR I run as much a -3.5* static.[/b]

Of course I am not also trying to get traction for forward acceleration from my front tires.

 

[Tristan Smith]

>> I think what Tristan was alluding to is what's the point you are trying to make?

Same thng I asked about 10 pages back.
While they go on and on, people keep building, selling and racing cars with spherical bearings.

Hey Tristan, long time no see...how are ya!
Might get to VIR this year, you?
[/b]

Hi Bill. How are ya buddy? Not sure if I will get there this year for the Double SARRC MARRS race. We (Kathy and I) just moved into a new house and we have a major renovation to do (again). That will probably take up a lot of my time and money this year. That, and the fact I am constantly, it seems, on the road for the job. So not sure. But come on down for the ARRC and I will crew for you. How are you? You married yet?

 

[pfcs49]

do you slow down for the turns?

 

[Greg Amy]

OK now I am totally confused.[/b]

See Andy's response; I was speaking generally. The ITAC/CRB will know your general suspension design (e.g., McP, multi-link, DeDion, swing axle, IRS); they are not expected to know specific limitations such as "the forward track rod binds up when I lower the car more than 2 inches".

Is this what you mean with your issue...[/b]

'Zactly. The inelegant solution is to tie up the suspension with extremely hard springs, which themselves cause other issues. Not pretty.

...my running higher negative static camber is compensating for the effect?[/b]

Yup, but high negative static camber creates its own issues in terms of straightline speed and stability.

...more negative static camber allow you to lower further before the detrimental RC/CG spread overcame your static camber?[/b]

Yes, that and higher spring rates, but that detrimental spread gets bad at about 1" below stock right height and spirals downward dramatically. There's nothing much more to gain (and a lot to lose) by going lower.

...I run as much a -3.5* static.[/b]

Same here, but I also run as much as -3 on the back sometimes, too...

 

[Tristan Smith]

take a look at Alan Lorenco's ITB Audi Coupe (anoyne got any photos?). The Coupe has the strut and knuckle as one complete part, with the ball joint integral at the bottom. Strut is free, right? In Alan's case, Dick Shine has built a B-E-A-U-T-I-F-U-L strut assembly that completely corrects any undesireable geometry issues. It's an absolute work of ART and when I got a good eyeful of it I knew that this was probably the future of the class - along with the B-E-A-U-T-I-F-U-L rear suspension work on Curran's ITB Volvo. Neither of these cars have ANY deviant suspension problems and can lower their cars to the absolute minimum ride height and not worry about it.

Yep, I would strongly agree it's a significant inequity within the rules, but it's perfectly legal. I can only assume such technical inequities are addressed via the new PCA process; as an example I get 80 pounds under the Acuras due to my suspension design (I'd rather have the suspension...) - GA
[/quote]

It may be legal, but I now contend that it doesn't fit the intent of the rules. Much like spherical bushings. They fit the letter of the current rule. "Bushing materials are free". But many here seem to argue that SB's don't fit the intent. So why is that different?

 

[Greg Amy]

So why is that different?
[/b]

I agree that it's not necessarily within the original intent of the rules. However, the wording of the strut mods is far more clear than that of the bushing "material" change.

Same idea as MoTec: apparently not within the intent, but clearly within the letter. Not so the bushings. - GA

 

[turboICE]

Starting to see thanx Greg.

Also I assume the "multi-link" listed some places for the rear of the NX2000 is a misnomer - your description as McP and the listing as "multi-link" would lead me to believe that it is a double lower link only with no upper links?

 

[Tristan Smith]

I agree that it's not necessarily within the original intent of the rules. However, the wording of the strut mods is far more clear than that of the bushing "material" change.

Same idea as MoTec: apparently not within the intent, but clearly within the letter. Not so the bushings. - GA
[/b]

But this is where I differ from those who are opposed to the SB's. It's my contention that the bushing rule is quite clear. Any material may be used. That means any. Sperical bearings in my suspension perform no additional function other than taking the slop out of the geometry, like delrin, which I am sure you would not contend is against the intent, that could be used in other suspensions. In my mind, SB's do not break the rule, nor the intent. I would go step further. In the 240sx bushings there is an inner metal collar that the bolts go through connecting the control arm to the sub frame. I removed those collars and fitted them to the SBs. Therefor the only thing changed was the bushing material from rubber to steel.

 

[Greg Amy]

Also I assume the "multi-link" listed some places for the rear of the NX2000 is a misnomer...[/b]

I'd suggest that my use of the term "multi-link" is the misnomer. "Multi-link" refers to the use of multiple links versus, say, an a-frame control arm. Your front suspension and my rear suspension are both "multi-link", however both are still McPherson strut designs. A McPherson strut design is one where the strut/damper is an integral vertical suspension locating device.

It would be more accurate for me to use the term "independant" or "unequal length control arm" rather than "multi-link. - GA

But this is where I differ from those who are opposed to the SB's.[/b]

And that, in a nutshell, is the essence of the last 15 pages of this thread... - GA


On edit: Now this is an neat new feature of the board: I replied to each of these posts separately, but the software apparently combined the consecutive posts into one...very neat! - GA

 

[turboICE]

Hmm, then is the above McP or not? I thought not, but the strut/damper is an integral vertical suspension locating device in this arrangement isn't it?

If that is so then the 240SX also has McP all around and I want my 100 pounds back!

I know Andy it was added based on engine displacement, torque, power potential, yada, yada but perhaps the 240SX has the same determinent in their suspension relative to the Tegs?

Edit: And despite the backhanded comments on the weight - I as of this time continue not to think it was unwarranted or unfair.