Home Alignment

Written on January 31st , 2025 by sudoyashi

Home Alignment

It’s a lot of guess and check, but fairly doable if you’re up to the tediousness.

Using the string box method, it was A LOT of guess-and-check, research, and math. It took me about 6 hours to adjust my front toe, where a lot of it was recalibrating, validating, and correcting mistakes and assumptions. If I had to do it again, I would avoid jacking the car up and down to reach for the tie rods and use slip plates instead.

Getting Started

To do an alignment, I used:

• 6” Ruler
• String
• Four tripods, any standing object will do
• Tools to adjust tie rod
• Tape measure
• Paint marker

Record your measurements the most convenient way you can. I used pen, paper, and my computer. We will be using the calculator found on https://robrobinette.com/DIYAlignmentCalculator.htm. Thank you Rob for having a great resource for the S2000 community to use. I hope you find the German competitor just as charming! We must fill out all of the dimensions in this calculator.

Setup the string

To setup the string, they just need to be parallel to each other, as long as we setup the strings with the same distance from the car, accounting for the measurements from all tires and other car dimensions, we can assume they are relatively parallel.

1. Setup on a relatively level surface

2. Straighten your steering wheel

3. Setup up your strings at half height of each wheel

4. With a ruler, measure from the center of the wheel to the string. The measurement does not really matter so long we get the same distance. Here, I’m using the 2” marker from the center of the center cap to align the strings.

5. Repeat the string on each wheel to setup the strings. | Front Left | Rear Left | Front Right | Rear Right | | ———————————————————— | ———————————————————— | ———————————————————— | ———————————————————— | | — | — | — | — |

6. Let’s start measuring. Starting with the FRONT of the front left wheel, use your caliper’s depth gauge to measure from the string to the front of the wheel. Then repeat on the REAR of the front left wheel. You will get measurements A and B. To get an accurate measurement, measure from the string to the wheel using the depth gauge. Repeat and measure for all four wheels.

   Front Left Front (A)	Front Left Rear (B
   A = 1.6055”	B = 1.158”

   BEWARE, if your calipers are metal, they will scratch your wheel. To prevent damage, add painter’s tape and compensate for the thickness of the paint. These wheels were heavily curbed so I didn’t care too much.

   Record all of your measurements like I did below!

   Pre-alignment measurements

PART	MEASUREMENT	IMAGE	IMAGE	MEASUREMENT	PART
A	1.6055”		E	1.209”
B	1.158”		F	1.560
C	0.829”		G	0.921”
D	1.135”		H	1.173”

Once we have our measurements, fill in the reamaining measurements:

• I (front wheel+tire width)
• J (rear wheel+tire width)
• K (distance between front and rear wheel centers)

Pre-Alignment Results - It’s bad

With these results, look at the toe degrees (orange highlight) and compare it to your vehicle’s degree toe specifications. Looking at ours, lets compare:

Location	Spec	Actual	Difference	Condition
Toe angle (total degrees)	0.3° ± .13°
Total	0.3°	0.23°	0.07°	GOOD*
Front left	0.15° ± .065°	1.03°	0.88°	BAD
Front right	0.15° ± .065°	-0.81°	-0.96°	BAD

Funny enough, while the front toe is shooting straight to the right, because of their relative measurements, the total front toe is still in spec range! With these measurements, we can see that both front wheels need adjustments to get closer to the ideal 0.3°. Look at the difference column and that is how much we should try to adjust out to get 0.15°. Since there are two wheels, setting up at 0.15° for each wheel should get us close to the 0.3°.

My goal is 0.3° toe in at the front wheels, this gives us a goal of 0.15° toe for each front wheel.

Adjusting front toe

With our differences calculated, let’s adjust the tie rod length to adjust toe.

In my case, I lifted the car each time I wanted to adjust, rocked the car back and forth to get the suspension to settle, turned the steering wheel to center, recalibrated the strings to the 2” line, then took my measurement. In hindsight, I could have done other methods, but this was the most straightforward without having to use or build any extra parts.

1. Turn the steering wheel to expose the tie rod. In my case, I turned all the way right to adjust the FR wheel.

1. With the tie rod exposed, grab your 22mm and 13mm wrench and loosen the locknut.

3. Once the locknut is released, on the FIRST adjustment, turn the tie rod by 1/6 of a turn (equal one face of the hex surface) to shorten or lengthen the tie rod. This will get us a baseline of what 1/6 of a turn will do to our tie rod. Lower the car and record the change.

In my case, changing the tie rod by 1/6 of a turn results in a 0.2” difference. To adjust our toe smarter we can do some more math:

• FR Difference from spec from spec E and spec F = 1.209”-1.560”
  • FR Difference = .351”
  • 1/6 of a turn = .2” difference
  • 1 turn = 0.2” * 6 = 1.2”
  • Turns to get .351 = 0.351/1.2 = 0.2925 turns

With this assumption, we can try to turn 0.29 turns or a quarter-turn and then some, and see what happens! But wait, which way do you turn it?

Which way to turn your tie rods

Tie rods are just another screw, as you “tighten” it, it gets shorter. If you “loosen” it, it gets longer. But the effects may vary depending on the location.

There are differences in how the tie rod will affect your alignment based on if it is in-front of or behind center. This is a table that can generally explain the effects on each side of the wheel.

Location, front	If you shorten the tie rod (tighten), you get…	Lengthen tie rod (loosen), you get…
Front left, tie rod front of center	toe in, positive	toe out, negative
Front right, tie rod front of center	toe in, positive	toe out, negative
Rear left, tie rod front of center	toe in, positive	toe out, negative
Rear right, tie rod front of center	toe in, positive	toe out, negative

Location, behind	If you shorten the tie rod (tighten), you get…	Lengthen tie rod (loosen), you get…
Front left, tie rod behind of center	toe out, negative	toe in, positive
Front right, tie rod behind center	toe out, negative	toe in, positive
Rear left, tie rod behind center	toe out, negative	toe in, positive
Rear right, tie rod behind center	toe out, negative	toe in, positive

Turning the tie rod 0.2925 turns

In order to make up the FR Difference of .351”, we will turn our tie rod by 0.2925 turns CCW.

Appendix 1 - Specifications

OE Tie rod

• 22mm locknut
• 13mm adjustment flats

Specification	Front (degrees)	Front (decimal degrees)	Rear (degrees)	Rear (decimal degrees)
Toe angle (total degrees)	0° 18’ ± 8’	0.3° ± .13°	0° 20’ ± 13°	0.33° ± .2167°

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