Alignments DIY

[jdlhonda]

Anybody here doing their own alignments and corner weighting. What equipment are you using. Seeing how I haven't even got my alignment done yet and also looking at a possibly ever changing setup I was wonder what equipment any of you DIY guys were using. I seen some intresting stuff in SportsCar it is my first issue so most of it I'd never seen before.

Any info would be well appreciated as I'm looking todo my own alignments in the future and maybe even start a a little hobbyist biz out of it. Auto X expenses as a marketign tool anyone. Hehe :D Well have to see what the Tax man says about that first.


Jason

[GodSquadMandrake]

I use 2 fishing string's with weights on each end of each string, so 4 weights.

You drape the fishing string through a center tread on your tire front to back. One fishing string on each front tire. Now you adjust the string so it dangles just barely off the ground on each side, I usually knot it to make it shorter if necesary.

Measure from one string to another on the front and back. Don't measure from the weight, but the string itself. You may need a partner to hold the tape measure. My tape measure is accurate to 1/32 of an inch.

So this is how it's aligned now:

Front width of tires 58 1/16"
Rear width of tires 58"

So I have a couple degrees toe out.


For the camber I use my fishing line again. I drape it over the fender and over the fender flare so that it dangles right over the middle of the wheel/tire. The string should go straight down and almost touch the ground. You then measure the distance from the lip of the rim to the string at the top and bottom. Again you want it to be pretty close.

[GodSquadMandrake]

I forgot to mention that after you make each adjustment you have to "reset" any preload on the car's suspension. Bounce it up and down, turn the wheel a bit, and roll it back and forth.

[phile]

deleted to save memory

[Dave Kral]

Front width of tires 58 1/16"
Rear width of tires 58"

So I have a couple degrees toe out.


I like your method. I think your estimate of how much toe out you have is a bit high. I calculate about 0.075 degrees (assuming your tire is 24" in diameter). You would have to have a difference of around 13/16" in the two measurements to get to 1.00 degree of toe out.

I'm figuring that the angle is the arctan of half the difference in the measurements divided by the diameter of the tire. Someone please bash me if I'm wrong.

[Chin]

I like your method. I think your estimate of how much toe out you have is a bit high. I calculate about 0.075 degrees (assuming your tire is 24" in diameter). You would have to have a difference of around 13/16" in the two measurements to get to 1.00 degree of toe out.

I'm figuring that the angle is the arctan of half the difference in the measurements divided by the diameter of the tire. Someone please bash me if I'm wrong.

Looks good to me. ...the "1/2 the difference" got me at first, 2 angles so each wheel would be half, duh...

Christian
#202 DSP
'00 Impreza 2.5RS

[jdlhonda]

Thanks guys this should get me started.

Phile,
I have Fred's book haven't got all the way thru it yet just bought it not too long ago. I'll look that other book up as well.

I'm trying to arrive at some toe out in the front and not sure what I'm going todo in the back. I'll be doing some more research. I guess I'm also looking at tools to help as i'd like to be able todo this in my garage and possibly do it for others over time. I will hopefully be purchasing a set of scales for corner weighting over the off season as well.


If anyone else has some ideas, thoughts, suggests please chime in.

[GodSquadMandrake]

I'm not very good at math so I don't know how to calculate it all exactly. I just try to set everything basically straight so my tires wear normal. I give it a little tiny bit of toe out and a little tiny bit of camber for good measure.

I guess I do my alignments like I do my cooking.

[GUS]

Phil,

I have been using a tape measure like you said. I also take the above mentioned method and hack it up a bit. I just pick a piece of tread (all seasons baby!) and measure it. I may have to start using the pin method, seems more precise. Also I have never set my front or rear camber (stock ride height.) Would using a straight edge and a carpenters level work? Or would spending the extra dough and buying the hub magnet gauge be the way to go.

[Gspot]

question on camber bolts, what direction should the lobe be facing to get the most negative camber?

[phile]

question on camber bolts, what direction should the lobe be facing to get the most negative camber?

Every setup is different. You just need to use the setting that makes the lower contol arm stick out as much as possible and the upper control arm stick out as little as possible.

[phile]

Phil,

I have been using a tape measure like you said. I also take the above mentioned method and hack it up a bit. I just pick a piece of tread (all seasons baby!) and measure it. I may have to start using the pin method, seems more precise. Also I have never set my front or rear camber (stock ride height.) Would using a straight edge and a carpenters level work? Or would spending the extra dough and buying the hub magnet gauge be the way to go.

The pin trick is better because and inaccuracies of wheel, tire mounting, or tire shape are not part of the measurement.

Camber, I use a string with a weight on it and measure to the top and bottom of the rim. Car has to be on a level pad and the rim has to be straight to be accurate.

[GodSquadMandrake]

Camber, I use a string with a weight on it and measure to the top and bottom of the rim. Car has to be on a level pad and the rim has to be straight to be accurate.

Me too. But be sure that your car is level first. If it's not you can put wood under the tires to shim it til it's level. You don't want to set your camber and then discover the car was at an angle to begin with.

[SUV-ETR]

I decided to spend the $$$ and buy a "real" camber gague that is calibrated to the ground. If people ***PROMISE*** on the grave of their mother's favorite sheep that they will be nice to it, I can bring it along to the test-n-tune. It'd be cool to see how accurate the string method is on ground that seems level.

One of the other really cool things about having the camber gague is that it can also do caster measurements, which is actually pretty important, especially in autocross. Though you usually need adjustable camber/caster plates to adjust caster, so most cars can't adjust this anyway.

For alignment, I intend to make my own "smart strings" style alignment, which just involves making some conduit attachments that clamp on the car. You take some measurements to find the centerline of the car, and then build brackets to hold the strings parallel down both sides of the car. Just like the jack stands method mentioned earlier, except that if you make the brackets so that they can be attached in exactly the same spot all the time, it becomes a nice, quick, and VERY accurate 4-wheel toe alignment system. Don't have to "re-invent the square" every time.

I watched the Prodrive/Subaru WRC team use a method like this after replacing a strut in service, so it would seem to work OK. :D The other neat-o thing about the smart strings alignment is that you also get front and rear aligned with each other, and aligned with the centerline of the chassis. (I think that's called "thrust angle alignment")

But the camber gague is "only" $200, which is nowhere near the cost of a set of scales. So that's my next issue: How do we do corner balancing? 914Dave supposedly has a set of those bathroom scale levers...is he out there?

[SUV-ETR]

You drape the fishing string through a center tread on your tire front to back. One fishing string on each front tire. Now you adjust the string so it dangles just barely off the ground on each side, I usually knot it to make it shorter if necesary.

I like that idea!

Another 2-person idea is to each hold a straight-edge against the tire, parallel to the ground at the same height. Do it above the "buldge" in the bottom of the tire. Then, you can measure in front of the tire and behind the tire, just like the string. That's what we did last weekend. Longacre even sells fancy expensive aluminum plates for this method, though I fail to see why. :?

Perhaps we'll try the string method next time, just for kicks. Pretty tough to beat the level of portability of fishing line though. 8)

One problem that both of them suffer from is variations in the tire or tread profile, but probably good enough for most purposes...

Neal

[GUS]

For alignment, I intend to make my own "smart strings" style alignment, which just involves making some conduit attachments that clamp on the car. You take some measurements to find the centerline of the car, and then build brackets to hold the strings parallel down both sides of the car. Just like the jack stands method mentioned earlier, except that if you make the brackets so that they can be attached in exactly the same spot all the time, it becomes a nice, quick, and VERY accurate 4-wheel toe alignment system. Don't have to "re-invent the square" every time.


Wow and to think I was going to buy something like this. OK so now I may just have to steal your idea and try to make some mounts on my bumber to build this.

I am soo glad that I cannot adjust my caster because I would be overwhelmed with what to do first. Once I install my suspension I will use the string and weight method to adjust camber. Then I will try the pin and tape measure method to align my front and rear toes. As for the total thrust angle setup, maybe by the end of the summer I will take apart my bumpers and weld in some nuts to bolt some dohickey-thingy.

Thanks for the input

[SUV-ETR]

As for the total thrust angle setup, maybe by the end of the summer I will take apart my bumpers and weld in some nuts to bolt some dohickey-thingy.

That's definitely one option. But you could also just drill a small hole in the underside of your bumper somewhere, and fashion a pin on the conduit/bracket/whatever so that it is located properly, and use a vice grips or other clamp of some sort to hold it in place. It doesn't necessarily have to be BOLTED to the car. You're not going to go driving with the thing. ;)

[914 Dave]

Out here, but fighting a virus. computer virus. Scales will be coming to the TnT to use in addition to any of that fancy electronical schtuff that might show up. I'd like to have a check of the camber on the '14 as well, while adjusting the rear is a pain and I don't see it being easily done in a parking lot, the front should cake.

[GUS]

I guess I could mount something to the bottom of the radiator support. I would like to get the strings as close to the thickest part of the wheel though. For now I will eyeball the total thrust and adjust evenly left to right with the trusty tape measure method until I get my tush in gear. For now I will add more new parts and maybe not understeer as much.

[GUS]

What would the difference from vertical be if my wheel was 14" and I wanted -1 degree camber. My gemotry is rusty and I couldn't get good results with my math. It's time to go to school.

For -1 degree i got: 1.4" (wow too much I think)

For -.5 degree i got: .094" (looks too small)

[phile]

What would the difference from vertical be if my wheel was 14" and I wanted -1 degree camber. My gemotry is rusty and I couldn't get good results with my math. It's time to go to school.

For -1 degree i got: 1.4" (wow too much I think)

For -.5 degree i got: .094" (looks too small)


1 degree .244"
.5 degree .122"

It's pretty linear at these small angles.

[GUS]

Wow, I was way off. Can I pick your brain a little more. What formula did you use to come up with this? Cause i'm using a basic right angle triangle with a hypotenuse of 14" and a 1 degree angle. I used the sin 89 = x/14 to find the vertical side. Then I just plugged in pythagoren's therom and viola! a bunch of numbers that don't work.

[GUS]

I talked to my coworker who is almost done with his Physics BS and he told me that my method was wrong. I need to learn my unit circle then apply this to the problem. Just a heads up on the issue.

[phile]

Wow, I was way off. Can I pick your brain a little more. What formula did you use to come up with this? Cause i'm using a basic right angle triangle with a hypotenuse of 14" and a 1 degree angle. I used the sin 89 = x/14 to find the vertical side. Then I just plugged in pythagoren's therom and viola! a bunch of numbers that don't work.

Sine of angle times wheel diameter. No other juggling required.

[GUS]

Hey, I learned something new today! It works while using the unit circle also, but this is much easier. Thanks a bunch!