235 replies to this topic

[RWP80000]

That's human nature for you!  The fact that folks appear to be asking for slotting of an OE part rather than, say, bushings like what was done up front is the surprising part to me.  The only reason the slotting was done on Steyn's car in the first place was in hopes that it wouldn't be caught.  If we are looking to change a rule for the same end result as what those slots did, I would prefere the rule be written to use the correct part(s) instead of modifying an OE part.

 

That said, I'm not sure if I support the change at all or not....still building my car and have not checked alignment yet

 

In addition to the obvious advantage of being able to obtain more camber there are other aspects that were considered;

 

• Cost- about as cheap a modification as can be found.

• Difficulty - can be performed on or off the car with simple tools from a rat-tailed file to a simple die grinder (just be careful not to exceed the allowance given as calipers with resolution 0.001 inch will be the inspection tool of choice).

• Time - Should not take much discussion to haggle on the labor charges involved if you elect not to do it yourself.

• Investment and obsolescence- no need to buy additional arms, use what you have.

 

Other considerations;

 

• Due to the variation in how much camber some vehicles are able to obtain, it either becomes necessary to swap out any number of parts to find the actual culprit part(s).  As we all know this can be time consuming and expensive depending on your resources and/or abilities.

• In lieu of the parts swapping routine or in the event an adequate solution is not found, the most probable solution would  be to apply a porta-power to the bottom of the cradle to spread it to obtain desired camber.  The issue with this is that you are now effectively increasing the track width of the vehicle, which of itself could create an additional competitive advantage.  Slotting the upper arm does the opposite effectively reducing track width.

• Requiring use of offset bushings in the upper rear arms introduces additional cost and installation expense as well as introducing the potential for variation in orientation between each offset bushing (not a significant issue in and of itself) but it does make for a difficult/time consuming process to change bushing orientation for purposes of camber adjustments.

• A primary advantage for slotting the upper rear arm outer hole is that it allows a quick and easy way to introduce additional rear camber WITHOUT affecting the rear toe setting.  This allows those who want  the ability to evaluate "at the track" camber changes the ability to do so without having to deal with chasing the two lower rear control arm cam bolt settings while in the process not screwing up the rear toe setting. This is really throwing a bone to all of the DIY low buck competitors that do not have large support crews and equipment at their beck and call with the ability to make this evaluation and if necessary get back to where they were, if so desired.  

My opinion is that this is a decision based in common sense that does not favor or advantage any competitor over another but rather codifies something that is simple cheap and useful.

[Caveman-kwebb99]

I wonder how many will slot them at a 2oclock orientation and how many will slot them at 4 o'clock to slightly change the geometry of the suspension now that the slotting is only defined by a length rather then a direction????

Might not be big enough to matter what direction you go but I'm sure someone will think someone else is getting some advantage maybe we should put multiple slots and we can play with them at the track as long as none of them exceed .6...

[FTodaro]

I am likely in the Minority, and bluntly, now it really does not matter, but I am against the rule change and how it was changed slotting vs bushings. To me the common sense approach would be to use the same method of modification, but as Kyle would point out, its just my OCD.

 

Question, since i race NASA also, do we expect they will adopt the same rule or will this be another area of conflict?

[38bfast]

I wonder how many will slot them at a 2oclock orientation and how many will slot them at 4 o'clock to slightly change the geometry of the suspension now that the slotting is only defined by a length rather then a direction????
Might not be big enough to matter what direction you go but I'm sure someone will think someone else is getting some advantage maybe we should put multiple slots and we can play with them at the track as long as none of them exceed .6...

Caveman you need to go back and study Geometry. Sloting in any other direction than inline with the pivot points will achieve no gain whatsoever. The upright pivot and subframe pivot are not changed. So since those two points have not changed the only thing that can change with the upper a-arm is length. Sloting vertically does not change length. E.i. No change in suspension geometry.

[38bfast]

And before evey one goes ape shit about massive slots. Go dig out your scale and visualy look at how much .2” actually is.

[38bfast]

As far a here we go again, someone cheats and we get a rule change.

Many times when a cheat is found it heightens a issue. In this case the cheat was identified. The reason for the cheat was identified. This undercovered tollance issues. This defined a disparity between cars that are all intended to be as close to each other as possible. Then options are evaluated. So in the end this puts the cars on a closer playing field at little or no cost.

[chris haldeman]

.

[dstevens]

Kids, ask your mature people what body filler was used previous to bondo.

Use said material and your right rear might come up heavy.

 

I was going to tell him to grind up some tungsten and put that in the filler...

 

I'm with you but will take a crack at answering.  The fan to run windshield defrosters comes in handy in northern climates some days to help de-fog the inside of the windshield.  Safety-wise it's a plus.  I've used it many times over the years. 

 

 

Not everyone needs that.  You could leave it in if you wanted/needed it.  

[Ron Alan]

In addition to the obvious advantage of being able to obtain more camber there are other aspects that were considered;

 

• Cost- about as cheap a modification as can be found.

• Difficulty - can be performed on or off the car with simple tools from a rat-tailed file to a simple die grinder (just be careful not to exceed the allowance given as calipers with resolution 0.001 inch will be the inspection tool of choice).

• Time - Should not take much discussion to haggle on the labor charges involved if you elect not to do it yourself.

• Investment and obsolescence- no need to buy additional arms, use what you have.

 

Other considerations;

 

• Due to the variation in how much camber some vehicles are able to obtain, it either becomes necessary to swap out any number of parts to find the actual culprit part(s).  As we all know this can be time consuming and expensive depending on your resources and/or abilities.

• In lieu of the parts swapping routine or in the event an adequate solution is not found, the most probable solution would  be to apply a porta-power to the bottom of the cradle to spread it to obtain desired camber.  The issue with this is that you are now effectively increasing the track width of the vehicle, which of itself could create an additional competitive advantage.  Slotting the upper arm does the opposite effectively reducing track width.

• Requiring use of offset bushings in the upper rear arms introduces additional cost and installation expense as well as introducing the potential for variation in orientation between each offset bushing (not a significant issue in and of itself) but it does make for a difficult/time consuming process to change bushing orientation for purposes of camber adjustments.

• A primary advantage for slotting the upper rear arm outer hole is that it allows a quick and easy way to introduce additional rear camber WITHOUT affecting the rear toe setting.  This allows those who want  the ability to evaluate "at the track" camber changes the ability to do so without having to deal with chasing the two lower rear control arm cam bolt settings while in the process not screwing up the rear toe setting. This is really throwing a bone to all of the DIY low buck competitors that do not have large support crews and equipment at their beck and call with the ability to make this evaluation and if necessary get back to where they were, if so desired.  

My opinion is that this is a decision based in common sense that does not favor or advantage any competitor over another but rather codifies something that is simple cheap and useful.

Common sense...what a concept! Thanks for the nicely explained thought process Rich!!

 

Still hoping someone can explain what Bauer is referring to with his Shock "wording" or clarification? 

[Ron Alan]

 Unless the builder is advertising a claim of superior performance by modifying the dampening rates why would anyone spend double or more for a rebuild than new?

Heard of Jim Jones? 

 

Then again...if you drop a second a lap at each track with no other changes and you are now keeping up with your competitor(and winning) who also has same said equipment...money well spent until you get bounced!

[tylerbrown]

Any word on the Fat Cats?

[Bench Racer]

Any word on the Fat Cats?

Why would 75% of us be concerned, we'd only get caught via a random check.

[Bench Racer]

As far a here we go again, someone cheats and we get a rule change.

Ok, we have another cheat, another rule change and no one has specified if the .600 inch long slot is from end of radius to end of radius or radius center line to radius center. In the engineering world slots are measured both ways. There is a gain if the slot specification is .600 inch from center line to center line. 

[wheel]

The rule change is not in the final Fastrack.  

[Martinracing98]

The rule change is not in the final Fastrack.

That is what I have been thinking this whole thread. I don't see that it is a rule. Only that it was discussed.

[Parity]

Ok, we have another cheat, another rule change and no one has specified if the .600 inch long slot is from end of radius to end of radius or radius center line to radius center. In the engineering world slots are measured both ways. There is a gain if the slot specification is .600 inch from center line to center line. 

I would imagine it would have to be end of slot. Certainly some folks would modify using a dremel and a center line inspection would only be an estimate. If being inspected with a caliper, most often the length is inspected and the radii are subtracted to determine the flat length unless you had a CMM or optical comparator which is probably unlikely at track.

 

In any event I really hope this doesn't go through. Not a fan of rule changes to prevent "inevitable" cheating.

[Parity]

 I am a 6'3" 230 pound guy

http://www.conrad.co...FB.EPS_1000.jpg

 

Use this and you'll be a 6'3" 190# guy in no time.

[Caveman-kwebb99]

I am not for or against the rule but I believe the slot needs to be defined better as to what direction and from where will it be measured.

[LarryKing]

I don't get the Jim Jones reference (as it relates to shocks)

[Jim Drago]

It could have been written better.. But what I read is basically you have a the size of the hole defined.. elongate the hole in whatever direction you want as long as the final dimensions are smaller than the specified dimensions. I don't think it matters to them which way you elongate the hole.. If you go the wrong way you will figure it out quickly. You could go inward on a 45 up or down, I don't think that would give any further advantage to anyone, so I don't think they much care as long as you are within those dimensions. 

 

As stated above .. I would not start slotting control arms until this rule passes. this is not a slam dunk and until approved through CRB and BOD, it is NOT the rule. 

Jim