Lizard928

Chris,

I think it will help everyone to know what arms you have on the car.

As to shimming of the upper a-arms, it is fairly common on true racecars to do this to get the camber back under control from extreme lowering when using factory arms.
But alot of the aftermarket arms for true race cars that I have seen use 2 heim joints which allows the end user to bring the heim joint in and out to compensate for this without having to shim.

HTH

dr bob

I'll be as gentle as I can. Mark K's method may work great for Mark K, but it's not accurate enough for the rest of us, or maybe that just applies to me. Taking a laser reading at the front and rear edge of the wheel means that the width of a pencil mark is greater than the difference you are looking to measure. It's as simple as that.

Look back at the DIY thread, and see that the measurement method I proposed early in that thread includes having marks 83" apart, looking for 3/8" to 1/2" difference to get the toe to factory specs. My figuring is that you want to be able to use a common measuring tool like a tape measure, and measure to marks that are easy to see and identify, and not have to guess because the line width from the pencil or marker you use is a major percentage of the target value.

Mark's method is literally a yardstick method that clues you to whether you have a problem. It's not a valid method to use for actually setting toe. It's nowhere near precise enough.

YMMV, JMHO, etc.

mark kibort

one reason it might not be accurate to do it with the laser, is that the laser has to be calibrated as well. If not, any angulation of the laser would greatly exacerbate any error.

my marks are not super accurate, but have been proven to be accurate within 1/16th of an inch. meaning, when i set the toe to 1/8" toe'ed in , im pretty sure it will be no more than 1/16th to 3/16th" toed in. Some proof. when I was turning the toe adjusters, I could see the marks move by 1/16th of an inch. after a few trys and 5 half turns, i was at 1/8" toe'ed in from teh .5" toe in from the T-bone I recieved in my last race.

On a hunter machine, the difference between what i measured and the machine was in this range. as long as you are very careful, using the same marker, level, and position on the wheel, you will get pretty accurate readings.
camber was also measured with the same level. its very accurate, as long as your bubble guage is accurate. 15mm from vertical will give you about 1.5 degrees camber. 15mm/495 INV TAN = about 1.5 degrees.

I do like the laser technique and will probably build one and calibrate it and start using it to save time and magic markers!

mk

AO

Mark-

If you do it the way I did it on my video, All you have to do from then on is put the little sticks on your rear wheels and turn the tie-rod until the laser hits the line on the stick. Couldn't be simpler.

dr bob

Andrew:

The key to the sticks method is 'once you get it right'. It's very true that tis method is very repeatable. So long as you use the same wheels and the same lasers, you can readjust toe in a matter of minutes to get it as right as your first measurement allows.

Mark, you keep referring to 1/8" of toe-in. Without stating what the difference is between front and rear targets, this continues to be an ambiguous and certainly misleading way to describe toe. If you continue to use this 1/8" as a description, please remind the readers that there is a TOTAL of 1/8" difference between readings ONLY when the target marks are about 28" apart.

The method of defining camber using a bubble level and an offset value requirtes that you know how far apart the touch points are on the wheel. Making the Big Assumption that the floor is level from side to side where the car sits both front and rear, your offset values then need to include the spacing on those touch points. For example, on the fixtures I made that allow the level to touch at the same distance as the stated wheel diameter, a 5/32" drill bit is the correct offset for the level to get my camber to factory specs. Different sized wheels mean the contact points for the level are different and therefore the offset size will be different. Of course if you are setting camber to something other than the WSM recommendation, you'll calculate for that too.

For others following along at home:
PLEASE READ THE PROCEDURE AND MEASUREMENTS SHARED EARLY IN THE DIY ALIGNMENT THREAD. PLEASE READ AND UNDERSTAND EARL GILLSTROM'S EXCELLENT INSTRUCTIONS.

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I have tremendous patience for ignorance, but I have no patience for stupidity.


So there.

mark kibort

I stated many times to put the level on the front of the wheel and the rear angling to the the rear with the marks being around 19-20" apart. just the fact that you are using the level on the wheels and making marks, you will in range.

as far as camber, you use the level and measure the offset up top(at the rim) call it 19.5" or anything around there is fine. not that critical. but sure, you should know the distance of the touch points. 19.5 and .5" of offset will equal about 1.5 degrees. Its accurate enough and if your floor is not flat, drive the car around and back in to the same spot in the opposite direction and take an average. remember, this isnt Hunter, but close enough.

again, take those distances front and rear or top and bottom and take the differences or the offset and divide by the distance number the two marks are apart. .5"/19.5" (for camber) and take INV TAN and that will give you degrees (1.5 degrees)
SIMPLE! For toe, 1/8" / 20" and take INV TAN and BOOM, you get total toe in degrees (.35 degrees or 20min)

mk

mark kibort

I like your idea. Im going to have to make that lazer set up. very ingenious. you always have the fixed distance always following you around! set it up and you always can get toe measured, but you have to buy the lazer level. where do you get those? home depot?

mk

ckabee1

I reviewed the DIY alignment thread and watched Andrew’s video several times. I am currently in the process of building the toe apparatus. It will be interesting to see the relationship between the measurement process and the “sticks” method.

I’ll post the results.

Thank you again for everyone’s help and insight.

dr bob

The measurement process gets the basic toe setting correct. The sticks on the rear wheels part is to make sure the wheel and rack are centered with the car, and to make future checks and adjustments fast and accurate. The future stick adjustments will only repeat what you measure initially, so any mistakes will propogate to future adjustments.

dr bob

Mark,

The lasers I used came from Harbor Freight, but they don't carry them anymore. You can use almost anything, including a cheap laser pointer, soling as you can mount it aligned with the fixture you'll build.

mark kibort

I see more issues with this technique. you need to get under the car to pin the rack, or those laser marks will be off. how do you do this without lifting the car?

I think what i will do is make the bracket, with two lasers pointing down. mark the ground and then measure the distances as I have. it just seems to be an easy way to check toe.

by the way, what would cause the car to pull if the alignment is off? caster? toe out? or rear alignment settings? Just curious if anyone knows . I have certainly found that toe in doesnt do anything but make the steering wheel off center, (and scrub the outsides of the tires )

mk

ckabee1

I can reach the plug with a long screwdriver and insert the bolt by streeeetching without having to lift the car.

mark kibort

If your name is Gumby, you might be able to do it on my car then too!

Thats a stick in the gears for me. I like the idea of using the lasers though. my technique relies a little too much on the rim, tire and angle that the user puts the mark on the pavement. However, with the laser, I could make the brakets and make the points straight down and measure them accross the car. that way, the accurace is not compromised and you get a clear picture of what your toe is.

a lot of guys at the track will just use string with jackstands. by knowing the difference in track width, you then can just look at the difference between the string in the front of the rim and back and get the same trig math output result.

mk

dr bob

Mark, you'll have to explain what you plan to do with a straight-down measurement. Can't use it for toe settings because of camber effect. I'm also not clear on why you worry about others who use strings at the track. Make your adjustments at home, on a known level floor. Race track repair areas are the pits as far as level; why risk it. Do it at home before you evev leave.

AO

I drive my car up some ramps to get at the rack bolt, but I don't think you absloutly have to do this. Just make sure the steering wheel is straight.

The crown of the road can make the car pull. If you drive down a 3-lane stretch of highway, the right lane will usually cause the car to pull to the right, the center will usually be the straightest (becasue you're stradeling the crown) and the left will pull to the left.