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Rear upper control arms- Camber discussion

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#1
FTodaro

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Here you go a Thread dedicated to the question: Do we need a rule change to allow a modification of the rear upper control arm for the purposes of gaining more rear camber.

 

Johnny maybe a poll here, i do not know how to do it.

 

In the end i will support what the majority feel is for the good of the class.


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#2
Steve Scheifler

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I posted in the other topic that I have had trouble getting over 3.2 negative on at least one corner of three different cars but first I need more information before having an opinion about new rules. Jim Drago says that they rarely if ever see this problem, and Dave Wheeler says pretty much the same barring bent parts.

Obviously I need to go back and get a better understanding of why my experience appears different. One factor is ride height and it may be that we are running a bit higher than they do. What I can’t say with certainty is how much camber gain/loss there is per unit of ride height but it is in my notes for a 1.6. Historically we have run a bit of rake, though less starting this season. Many run flat to negative rake so that’s likely at least some of it.

But should I be forced to run lower than I prefer in order to get camber that seems to work on a given corner or equal to what someone else gets because they got lucky in the parts lottery? For that matter, should we be forced to go through the significant cost and hassel to replace an otherwise good subframe just because it is slightly bent at one control arm mounting point?

I think those are some of the questions to be pondered.
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#3
tylerbrown

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Do we need a rule change to allow a modification of the rear upper control arm for the purposes of gaining more rear camber.

 

 

No


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#4
Danica Davison

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No
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#5
ccambern

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My opinion (for what it's worth)... I've had a similar experience to Steve on my '03. At correct toe, with the wheels square to the car, and at a relatively low ride height, I can only get about 3.2 on the left and 3.0 on the right. The subframe does not appear to be bent when measured with an Advanced subframe checker and the suspension appears to be straight. Tire temps and wear patterns indicate that, at least on some tracks, the car needs significantly more camber than I can legally get. I might be able to resolve this by swapping parts, but that seems to be a rather expensive and time-consuming gamble.

The rules, as they are currently written, favor cars and suspension parts that are on the high end of the adjustment range, whether from manufacturing tolerances, previous contact, or intentional modification.

Although it's easy to check for slotted control arms, there are other ways to get more camber that would only be measurable with a set of jigs and published dimensions for each part. Very small changes to the upright or upper control arm can make a big difference in rear camber and, if done cleverly, these would be impossible to detect without special tools.

This has a created a situation where legality can not be reasonably verified, at least with the tools currently available to tech. Like it or not, "tech shed legal" is SOP for many guys at the sharp end of any competitive class. Making an item that can not be teched "illegal" simply forces us all into a devil's bargain: intentionally break a rule in the knowledge that you can never be caught, or cede an unfair advantage to less scrupulous competitors.

I love Spec Miata, but one of my main concerns when I came into the class was that it would not be possible to win legally. At the end of my second year, I'm convinced that legal cars can and do win regularly. However, I also think rear camber is an area that is being exploited by some people in ways that aren't being caught in the tech shed. And as mentioned previously, I think the variables involved in racing 15+ year-old production cars are contributing to the problem.

As we did in the front suspension, let's just make it so that every car can be easily adjusted beyond optimal. It doesn't even require purchase of new parts; it just takes a few minutes with a grinder. Level the playing field and let us stop worrying about how that car in front of us got 4 degrees.
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#6
av8tor

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No



#7
Ron Alan

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The guys who have it(plenty of camber adjustment) will never agree to let there competitors get it :)  Why are we treating one axle different than the other...really makes no sense :blink: ?  Yes...why not? Most will never have to do it...and those who do are suddenly not going to drive away from anyone but will have what all can get if they choose!


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#8
Tom Sager

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I can get plenty of rear negative in both cars with straight parts and would be supportive of a rule change that made it easier for all to do the same.  Agree with both RA and CC above.  A simple inexpensive mod could be approved and it should be a net plus for the class.  


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#9
Ron Alan

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While we are at it lets allow the use of rear NB uprights on NA cars! The rules have already been changed to accommodate the added track width!


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Ron

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#10
Brandon

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The guys who have it(plenty of camber adjustment) will never agree to let there competitors get it :)  Why are we treating one axle different than the other...really makes no sense :blink: ?  Yes...why not? Most will never have to do it...and those who do are suddenly not going to drive away from anyone but will have what all can get if they choose!

 

Offset bushings were made compliant to correct an inability to tech a part (bent spindle), not to reach a particular camber number.

Just because the reason for the "untechable non-compliant" part was to gain more camber wasn't the reason for the rule allowance.

 

If we're going to get into intent then we might as well permit full update/backdate with the best combinations of all four platforms.

Can you say a VVT engine in a 90 tub (lightest tub) with NB rear uprights & front subframe with about 300# of ballast in the passenger area?

(yes this is hyperbole so don't read into it anymore than what it is)


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#11
Brandon

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Here you go a Thread dedicated to the question: Do we need a rule change to allow a modification of the rear upper control arm for the purposes of gaining more rear camber.

 

Johnny maybe a poll here, i do not know how to do it.

 

In the end i will support what the majority feel is for the good of the class.

 

Hellz to the no's.


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#12
ner88

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Sure, slot away, but if we are changing the rule, limit camber to 3.2.



#13
Parity

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https://video.search...e63&action=view


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#14
Jim Drago

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I need to order one of those


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#15
Parity

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I need to order one of those

Got one on my desk.


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#16
Jamz14

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While we are at it lets allow the use of rear NB uprights on NA cars! The rules have already been changed to accommodate the added track width!


Well, while we are at it then; can we get rid of the blower, heater core, air controls, and get an sm wire harness?
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#17
Muda

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Yea, Collins' proposal looks better every year.  That and a sealed engine.


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#18
Tom Sager

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How about a 100 pound weight reduction for drivers over the age of 50?  Quite often now we're getting our asses kicked. 


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#19
Bench Racer

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How about a 100 pound weight reduction for drivers over the age of 50?  Quite often now we're getting our asses kicked. 

I know of a really good 1.6 you could buy and then vintage race.

 

With the weight reduction per years of age, does that mean I get 150 pounds? :rotfl:


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#20
Jim Drago

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How about a 100 pound weight reduction for drivers over the age of 50?  Quite often now we're getting our asses kicked. 

can we go 3 mm bigger plate? no way I'm getting 100 lbs more out of my car :)


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