devilinblack

Where can this video be seen? I've had no luck with search.

Bill Ball

Please examine all the relevant parts: balljoints, tie rods, wheel bearings and the upper A-arms. You know you can't do an alignment if any of those are worn, and it sure sounds like at least one of them is from what I quoted.

AO

https://rennlist.com/forums/6390423-post143.html

mark kibort

cool!!

For camber, just zero out the bubble level on the wheel vertically. loose the pumb bob. even with the plum bob, see what the distance is up top to make it straight. 19.5" rim diameter would be about 1 degrees for 12mm. or .5".
.5"/19.5 INV TAN = camber in degrees!!

I like the fact that you always now can re-check with the paint sticks without drawing marks alll over the floor all the time. I measure front of the tire and rear of the tire with the level as a straight edge. Im only using 20" as you are usling the wheel base for the trig functions. (more accurate) (unless of course, your rear wheels get pushed in in an accident, then it wont be so accurate )

mk

ckabee1

I am currently out of town, so I will not be able to measure the toe or post the camber numbers from my last alignment. I do know that camber is negative to the extent that you can look at the front tires and see that the top is leaning towards the car more than the bottom.

...those items were replaced last year. I had some time before leaving town to pull the front tires. Everything I removed was still torqued, nothing was loose.

Anyone going to have an alignment booth at SITM?

devilinblack

Brilliant!

Thanks for the link and thanks for taking the time to put that together.

mark kibort

A shop level against the wheel vertically can determine camber, VERY accurately.
5" to make it level is about 1 degree

the calculation is: .5" / 19.5" INV TAN on the calculator.

mk

Bill Ball

My garage floor is slopped about .5 degree side to side. Most are not level. So, measure that first and figure it in.

mark kibort

.5 degrees????? thats lot!!! anyway, quick fix for that, is turn the car around to check again and take the average!

mk

ckabee1

Okay, I am back in town and had time to hit the garage.

I measured for toe and came out to an even 72 1/8 front of front tire and 72 1/8 back of front tire.

I found the alignment sheet from last summer and I appear to be running -2.2 front left and -1.9 front right. I have not lifted the front end yet in case I need to adjust the alignment.

So, according to my measurements, toe looks okay. Does this mean the aftermarket A-Arms I am running is wearing the inside of my tires b/c of the negative camber?

ckabee1

I just pulled the tires and everything appears intact. I have been communicating with another RL'er and they suggested shimming the upper a-arms.

Is it possible that the negative camber is wearing the tires, and not toe? Is it typical to have to shim the after-market a-arms to get them to proper spec?

Thanks for the help.

dr bob

Chris--

Camber wears all the way across the tires, but at that angle you describe. Poor toe means the inner edges will scrub through while the middle and outer edges will be untouched. Difference between wear from pressure and wear from scrub.

ckabee1

so the wear points back to toe? How accurate an indicator of toe are is measurement procedure I used?

I did what Mark described: put a laser on the front and back of the rim on each front tire and measured across. With them being exact, can toe still be out enough to wear the insides?

I am sorry if I keep asking the same questions, but I'm just trying to make sure I understand/

Thanks again.

mark kibort

the front of tire vs back of tire uses the rim or tire to determine the distance. at 0 toe, you should be ok, but I would want 1/8" of toe in , because as you are braking, the front goes down, and creates toe out. this really only becomes an issue when the suspension compresses. .5" of toe, as I had with my accident, scrubbed alll the race rubber bits off the outside edge to the inner 1/3rd on the drive home from the race track. Proving a point made above.

camber of near 2 degrees I would think could give you more wear on the inside edges or inside 1/4 of the tire surface. thats a lot of camber for a street car. I only have about 15mm off vertical (using the level again off the rim edge) this equates to about 1.5 degrees of camber, but this is a race car!

If you do the measurement again, use the level and angle it from the center top of the tire toward the bottom 1/4 of the tire. this way you get a little projection of the alignment line. you want to have about 20" or so between teh marks, front and rear in otherwords. try and be very carefull to do both sides and front and rear the same. if you do this, its pretty darn accurate vs the Hunter machine, i have found. You can take the tie rods and move 1/4 of a turn on both sides and get a little more toe without hurting anything. (i.e. steerring wheel position aligment)

mk

ckabee1

thanks Mark, i just remeasured and came up with the same number. I am going and adjust the toe 1/4 turn like you suggested.

So, what can I do about the camber? It is adjusted as far as it will go. Have you heard of shimming the the a-arms to even-out the camber?

These are aftermarket arms.