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#21
James York

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. A pain but you can always just use a spacer Alberto...

 

No you cannot just run a spacer on one wheel on an axle in the SCCA.  That is illegal.

 

Rule quote,

 

" If spacers are used they shall be 
no greater than 13mm and equal per axle."
 
As someone that is a stickler for rules no matter if any performance difference and no grey in your vision, I am shocked you would do this or give this advice.
 
 
 

 

 

I don"t understand the tone of those who think this was nothing...or nothing substantial enough to make such a big deal about?

With this type of attitude what is the point of any of the rules we have? I think 50% of what is writing in our rules is minutia. But someone thought it important enough to write it! Our rules even go so far as to say if it doesn't say you can...you cant! So why would SCCA write rules and then not enforce them? 

 

 

 

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#22
Ron Alan

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Fair enough James...your correct and i did know this(brain fart and bad advise)! 


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#23
Alberto

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I have the original wheel (the aforementioned spare) which wound up being OK (according to Ron Cortez) after some light contact.  I could just re-mount the tire on it.


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#24
Keith Novak

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When I’ve had to set camber on a non-level surface in the paddock after an "unapproved tire wall modification", what did was first level the Earth (or at least compensate):  We put a straight edge in front of the two tires to create a reference plane.  We used a large beam level for this.  Then we set a digital level on that, and zero’d the level.  That way when we put the level on the wheels, it compensated for the unlevel ground.  You can also just measure how far the ground is off of level and do the math. Your camber gauge looks hard to fit under the car so you might have to roll the car to set the level on your reference plane.  BTW your rear camber numbers sound like things are still pretty darn straight.  I only get 3* with one bolt set to max and the other for setting toe.

When you say your toe zeros out in front when you tighten things down, how are you setting the toe?  Are you trying to do it from the camber adjusting bolts, or are you doing it the easy way by tightening the camber bolts and using the adjustment in the tie rod ends?  That way is much less frustrating and it helps allow you to get your steering wheel straight.


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#25
Alberto

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Keith, not sure I followed but let me explain.

 

I was setting front toe using the tie rod ends.  For some reason, I managed to get it to 0 but it kept going back to zero every time I tried to squeeze out just another mm. After the 4th or 5th  try, I gave up and was happy to settle with 0 :)

 

The rear camber bolts were setup the way you mentioned.  The front bolt was maxed out and I adjusted toe using hte rear bolt.  That was easier than expected b/c the front bolt was maxed out and I wasn't trying to adjust camber.  Got it in a couple of tries.  

 

Thanks.


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#26
Brandon

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Not to be a rules whore, but you must run identical spacers on an axle.

Thus, running a single spacer on one corner would be non-compliant.

 

Someone gets to by three more wheels or sell one!  ;-)


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#27
Alberto

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Car feels much better now.  Just did a pretty wet test / training day at Sonoma with some friends.  Let's see how it feels at the next SCCA race at Thunderhill which I'm much more comfortable with.


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#28
Todd Green

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Not to be a rules whore, but you must run identical spacers on an axle.

Thus, running a single spacer on one corner would be non-compliant.

 

Someone gets to by three more wheels or sell one!  ;-)

Honestly this is a pretty silly rule.  One would imagine the intent was so that people couldn't run a staggered offset on one side.  The rule should be written so that the total offset (wheel+spacer) must be the same on each side of an axle.


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#29
Karl

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<<I don't think an alignment machine will pick up an offset wheel difference?>>

 

If not then you are going to have issues.  The string setup does require all wheel tire combinations to be the same if you want accuracy.  You also need to take track difference into account which might mean installing 5 mm spacers up front while you do the setup.  If the tracks do not match the tow numbers will be off. 

 

Frankly, I think Bruce hit the nail on the head.  CASTER MISMATCH.

 

<<I also discovered that one of my wheels is a different offset.  Yep, you read that correctly.  I spent a good long time going over all the suspension components and subframe trying to figure out why that corner was 5mm "shorter" than the other.>>

 

Alberto, if I am reading you correctly, I think you misunderstand something here.  5mm of offset difference on one side of the car (driver's side in your case IF I am putting it all together right) will not give you 5 mm of toe difference.  PM me your phone number and I'll give you a call.  Too much for a post.

 

FYI, you can check caster with the strings.  You will need turn plates or two floor tire/grease sandwiches for this.  Set the handbrake if you have one or block the rear wheels if you opt for the grease sandwiches.

1- Get both front tires pointing equally forward (i.e. match toe side to side)

2-Measure camber of both front and note

3-Turn steering wheel EXACTLY half or 3/4 of a turn to the left and lock in place (tie down works well)

4-Measure camber of both fronts again and note

5-Repeat 3 and 4 with wheel turned to right by same amount as in 3 above.

 

What did you measure side to side?

 

The side on the inside, or unloaded side of the car in a corner, should not have changed camber much if at all compared to pointing straight forward.

The side on the outside, or loaded side of the car in a corner, will show a camber increase.  Both sides should show the same increase unless you want to get into some more advanced setup techniques.


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#30
Karl

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<<The rule should be written so that the total offset (wheel+spacer) must be the same on each side of an axle.>>

 

Asked for that years ago.  Was told it was too hard to explain that to most regional techs.  There was also measuring inaccuracy that needed to be thought about and and and....

 

We actually had this teched at one event.  Tape measure and stick to measure wheel offset and then they compared spacers side to side.  They ignored the small measuring differences because the wheels all looked the same.  Put a different wheel on there and the red flags go up.  Never bought less than six of the same wheels from that point on. 


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#31
Karl

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Given the "bent" wheel here is another trick.

 

You can spin each wheel and slowly draw a marker up to the rim.  The high spot(s) will be marked and if you do it well, you will find two spots at the same "height" 180 degrees from each other.  Now set those two points in the horizontal plane while you align.  I use the tire rather then the rim, but that means marking each alignment.  Marked rims can be visually checked more quickly when you do the next alignment but it's not as accurate.


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#32
Alberto

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<<I don't think an alignment machine will pick up an offset wheel difference?>>

 

If not then you are going to have issues.  The string setup does require all wheel tire combinations to be the same if you want accuracy.  You also need to take track difference into account which might mean installing 5 mm spacers up front while you do the setup.  If the tracks do not match the tow numbers will be off. 

 

Frankly, I think Bruce hit the nail on the head.  CASTER MISMATCH.

 

<<I also discovered that one of my wheels is a different offset.  Yep, you read that correctly.  I spent a good long time going over all the suspension components and subframe trying to figure out why that corner was 5mm "shorter" than the other.>>

 

Alberto, if I am reading you correctly, I think you misunderstand something here.  5mm of offset difference on one side of the car (driver's side in your case IF I am putting it all together right) will not give you 5 mm of toe difference.  PM me your phone number and I'll give you a call.  Too much for a post.

 

 

Karl, Thanks for the offer.  I understand and I think we're on the same page.  Let me explain differently.

 

Measuring the front.  

on the driver side front wheel, The measurements were 27.5mm at the front of the wheel lip and 25mm at the rear of the wheel lip.  Distance between the string and the center of the wheel was 65mm.  So about 2.5mm toe in.

on the passenger side front wheel, The measurements were 32mm at the front of the wheel lip and 39mm at the rear of the wheel lip.  Distance between the string and the same spot on the center of the wheel was 65mm.  So about 7 mm toe out

 

Once I swapped that wheel for a correct offset wheel from the rear of the car and re-measured toe, the numbers were consistent left to right.

 

That's how I eventually realized that the wheel was the wrong offset.  It was exactly 5mm different at the wheel lip but the same 65mm measurement to the same spot on wheel center which I used as a constant or reference point yet I still had consistent camber left to right.  In my limited experience with bent suspension and subframes, I have not yet seen a scenario where both toe and camber are good but I reckon it could be.

 

Thanks for your input!

 

 

Thanks for the steps for camber and caster procedure.  I'll check that out next time I play with this.  

 

The spare wheel actually is not bent.  It took a hit from another car's tire when I spun in close proximity to another racer that did an admirable job avoiding me.  I got paranoid reading about wheels cracking so I got another one.  


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#33
Alberto

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So after this awesome weekend's SFR SCCA race at Thunderhill, I noticed that the issue still persists.  

 

Going to pull suspension arms off and try to check bushings.  

 

Also will probably rebuild the calipers or maybe replace.  Would be nice to check pressure at brake pads with a tool like Bench posted but they are a bit pricey...  Going to give that some thought too.


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#34
Alberto

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Found something.  One of the bolts that attaches the steering rack to the subframe

 

Looks like the threads on the subframe where one of driver's side steering rack bolts thread into is stripped.  Going to see if I can re-thread the subframe as a quick fix.  Anyone know what the thread pitch is?

 

Also going to source another front subframe.


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#35
RazerX

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you can just nut and bolt that and save the hassle of swapping a subframe. 


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#36
Alberto

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Interesting...  I'll try that tomorrow.  The front one is accessible but not sure about the rear nut- which is the one that is stripped.  Thanks!


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#37
Jeff Wasilko

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I had the same issue...just put a nut/bolt in and it was fine.



#38
RazerX

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Alberto, 

 

I know this is rare for an NA but check for subframe cracks.  Especially near box tabs the hold front LCAs.   If that happens you will get all kinds of weird pulling :)


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#39
Alberto

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Alberto, 

 

I know this is rare for an NA but check for subframe cracks.  Especially near box tabs the hold front LCAs.   If that happens you will get all kinds of weird pulling :)

 

 

Will do.  Never thought of that.  Thanks!

 

 

On another note, I got a set of new bolts from Mazda Comp.  They are so shiny.   :)  Besides being blingy, they also have a lock washer.  That particular old bolt did not and the others looked flat.  I assume the lock washer had fallen off at some point b/c it had lost it locking capability.  Are these bolts single use only?


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#40
RazerX

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if you are speaking about the camber bolts, i know that most racers, including me, put then on way tighter that factor specs.  I have indirect evidence and heard 'stories' that the bolts stretch and then will not hold properly.  I have heard that some only use them once.  Some call him the Stig, oh wait wrong show.  I usually use mine for 1/2 to a full season.  YMMV. 


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