DIY Allignment tools or store bought?

[fast_eddie_72]

Hey Gang,

Last night, as is my way, I built a tool to check my toe in. I used pipe from Home Depot like you use for gas line. I have some ideas for refinement, but I think it will work just fine.

So what do you use? Some snazzy tool from a mail order place? Home built? Take it to a shop?

In the past I've always used four jack stands and string for my solid rear axle '72 Capri, but I don't think it will work as well for the MR2. I'm going to devise a camber gauge next.

Take care,

Ed

[Matt Leicester]

String is a flaming pain to set up, but it is certainly useful, I would say more so on a four wheel independent suspension car than a live rear axle car. You just can't use the rear wheels as a "straight" reference point. Now for the bad news, you couldn't use live rear axle wheels as a "straight" rear reference either! Using an alignment machine, it is surprising how few non adjustable rear wheels actually point exactly where they should. You just have to use suspension pivots or symmetrical frame points to measure to set your string. Another thing which you need to be aware of is that you absolutely need some friction free or very low friction set of turnplates for the wheels you are adjusting. There is play in all mechanical linkages, steering and suspensions included, and if you are counting on the tires slipping easily on dry ground, you are in for many inconsistancies in your alignments. Even with a professional alignment machine and set of turnplates, you need to bounce the suspension and kind of move the car on the turnplates to make sure your measurements are accurate. Big problem number two with using string and jackstands! You move the car a bit on turnplates, and the car is magically no longer in line with the string.

The most accurate way to use string for alignment purposes is to anchor the string to the car itself - you have to make bracketry that attaches to the car and will put the string parallel to the centerline of the car at a distance from the car sufficient to turn the wheels twenty degrees. Or find an alignment shop that will align the car to your specs WHILE HAVING SIMILAR WEIGHT IN THE DRIVER'S SEAT. Never, ever forget to put comparable weight to the driver in the driver's seat. On a softly suspended car with four wheel independent suspension, there is very commonly over a half degree change in camber with 200 pounds in or out of the driver's seat. Another advantage to having the strings anchored to the car instead of the floor is that if you have a lot of time, you can get away without turnplates - after each adjustment, no matter how small, roll the car forward and back to let the wheels go where they will and measure away.

The magic behind turning the wheels 20 degrees is that caster is a calculated figure. You measure the camber at twenty degrees in and twenty degrees out, and caster is 1.5 times the change in camber in degrees. Always set toe last, as any other changes you make will affect your toe, but toe will not effect camber or caster. Always check your camber with the wheel you are measuring pointed straight, or at least pointed wherever the straight ahead position will be when your toe is set. I.E., if you want 1/4 inch toe out, measure camber when each wheel is 1/8 inch toed out. The worst problem you will get if the front wheel toe is not set evenly side to side is that the steering wheel won't be straight ahead when the car is going straight. The rear wheels do not give that luxury. Make absolutely sure you have the rear wheel toe set evenly side to side, or the car will behave differently in left and right turns, and will "crab" down the road when you are trying to go straight.

All in all, unless you are a glutton for punishment, take the car to Tire Source in Boulder or 3R in Englewood and have someone with an alignment machine and rack do it right! Just bring weight to put in the driver's seat...

Matt Leicester
the opinions expressed in this diatribe should be taken as the opinions of someone who should have been in bed long ago, and should not be relied on as coherent...

[fast_eddie_72]

Well Matt, I completely agree with you. If you want an accurate allignment, you're best going to a profesional shop. I don't think my home made tools are very accurate. I do think they have some degree of precision though. For where I am right now, that's probably good enough. And with about $10 invested, it's cheap fun trying.

I have struts coming soon and down the road I'll have a front sway bar change and crash bolts to get some camber into it. Once that's all installed I may want to get a profesional allignement. For now, I'd like to experiment with something more agressive than factory settings and I think I can do that well enough with my home made tools.

Take care,

Ed

[Chris_Swearingen]

Easier than jackstands, looks like a possible make it at home, but they are for sale at 949Racing.com (http://949racing.com/index.asp?PageAction=VIEWCATS&Category=8)

For the record, I cheat and have tireworld do my alignments.

http://949racing.com/ProductImages/ICM_toolfront.jpg
http://949racing.com/ProductImages/ICM_toolrear.jpg
http://949racing.com/ProductImages/ICM_toestick.jpg

[fast_eddie_72]

I've seen that type before Chris. Actually, I'm sure with some work I could do that. That might be a good idea actually!

[Matt Leicester]

That's a semi common solution for string alignments, but the string is so close to the wheel that you can't check caster... Good for toe adjustments, but that's all.

Matt Leicester

[John Scheier]

Guess I'm upper-class... I use a pair of Longacre Toe Plates and two tape measures... real classy stuff ;)

Camber / caster I use a smart gauge.

If you let me near string, I end up with knots :(

[PaulL]

I used to use a bubble level taped to a piece of aluminum tubing along with a calculator to measure camber.
I now have a Smart Camber gauge. Ahhh ... digital.

For toe, I will use strings on a similar home made hanger like shown above if I am interested in the thrust angle, or if simple toe is all I'm concerned with I use my LongAcre toe plates. At an event .. the toe plates are definitely the way to go. You could probably mock some up as well. The 2 tape measures, as John indicates, are da bomb!

Another advantage of strings attached to the car is that you can actually roll it back and forth to settle the bushings after making an adjustment, and the strings don't move at all.

I also use some fiberboard tiles to act as swivel plates under the front tires ... they don't require any grease, and allow you to swing the steering wheel back and forth pretty easily (stack two on top of each other like bearing plates). My steering column is marked with a straight ahead mark so I can lean in from outside the car.

[Karl McColl]

I'm a road racer but try not to hold that against me! I use a combination of homemade and purchased equipment. I built a trammel bar to quickly check toe. It's great for checking track also. I purchased a "Smart Strings" set-up similar to what is shown in the above pics on the Miata. Smart strings are more generic in that they are more adjustable to fit almost any car. I use a Fastrax camber/ caster guage. This was all the equipment I ever used to align the G prod 510 and it got me to the podium at the runoffs. (but not to the top!)

If I did anything differently it would be to design the string alignment tool and hangers specific to the car I'm working on. It makes the results more duplicateable than with "Smart Strings".

[fast_eddie_72]

I also use some fiberboard tiles to act as swivel plates under the front tires ... they don't require any grease, and allow you to swing the steering wheel back and forth pretty easily (stack two on top of each other like bearing plates). My steering column is marked with a straight ahead mark so I can lean in from outside the car.

Paul, when you say fiberboard, do you mean just like MDF from Home Depot?

[arniecoleman]

I'm a road racer but try not to hold that against me!

Karl,

Don't beat yourself up so badly! If anything, I'd say you were "multi-disciplined."

Nice to see you on the forums. Talk about leading by example . . .

[fast_eddie_72]

I'm a road racer but try not to hold that against me! I use a combination of homemade and purchased equipment. I built a trammel bar to quickly check toe. It's great for checking track also. I purchased a "Smart Strings" set-up similar to what is shown in the above pics on the Miata. Smart strings are more generic in that they are more adjustable to fit almost any car. I use a Fastrax camber/ caster guage. This was all the equipment I ever used to align the G prod 510 and it got me to the podium at the runoffs. (but not to the top!)

If I did anything differently it would be to design the string alignment tool and hangers specific to the car I'm working on. It makes the results more duplicateable than with "Smart Strings".

lol- I haven't been a "autocrosser" long enough to hold it against you! Didn't know I was supposed to! They've been a little slow on the paperwork though, I'm sure it will be in tomorrow's mail.

Trammel Bar! Hey, that's what they're called. I guess I knew they had a name. That's what I built, kind of. But I can already see the limitations and I haven't even adjusted anything.

My new Tokico Illumina struts got here today, so I'm going to have to get this figured out soon enough. Going out of town for a family vacation all week next week so I'll have plenty of time to think it through.

Take care,

Ed

[PaulL]

The MDF is usually a bit too thick, if I recall correctly.

I used some of their project panels ... they are usually about 3 or 4 feet square, and the stuff is only about 1/8" thick.

Cut it into 1'x1' squares, then when you stack 2 on top of each other they will slip pretty easily. One set under each front tire, of course.

It's also low enough that you can roll your car onto the stacked pair without too much effort.

[Tom Hunsinger]

Paul, when you say fiberboard, do you mean just like MDF from Home Depot?


You might know it also as Masonite. As Coke is to soda pop, Masonite is to fiberboard. Use the tempered stuff; it is very slippery as I have found by walking across the workshop floor and found myself skating rather than walking, with predictable results. :eek: