If you have done any sort of suspension work on your car, it is time to do an alignment. On this 2001 Porsche Boxster, we are going to do a four-wheel alignment.
This car was lowered, it was lowered beyond any factory settings, and it was just too low. We set about replacing the suspension components. New struts and matching springs to bring it higher, but still lower. We chose the European height setting, and with new tires, new struts, springs, along with new brake parts, it was time to reset the alignment.
Setting up for a four-wheel alignment
To perform a four-wheel alignment on this car (or any car) a few things need to be in order. For one, all of the fluids should be topped off. The tires need to be filled to factory pressures. Also, running the car around the block is a good idea if you have changed major parts as we did. This should settle all the new suspension parts.
To do a four-wheel alignment the car has to be on the tires, but they still have to be able to move. To do this, you need to place the car on wheel turntables. We love the new magnesium ones that we just bought. The steel ones work as well, but the weight difference is substantial.
You could put the car on the ground, on the turntables, but this makes it very hard to make the adjustments to the suspension. To solve this problem we were going to buy some pre-made tables for each wheel. This turned out to be a problem! The tables were too flimsy for the money and it did not feel safe.
After returning the tables we welded up the four tables you see in the video. By placing a bolt on each foot, we are able to adjust for the differences in the floor to make the tables perfectly level.
Tools to do a Four-Wheel Alignment
To do the four-wheel alignment you will need the tools shown above. The wheels need to be locked from rolling, but able to turn on the turntables. To lock the wheels we use the brake pedal bar, to turn the wheels we use the mag turntables. The steering lock is for when you are setting toe, at this stage the wheels can not move and should be pointing straight ahead. If the steering wheel is offset it will not be straight when you drive the car.
Caster, Camber, and Toe
There are three terms when it comes to wheel alignments: Caster, Camber, and Toe
Caster is the forward-backward position of the front wheels. On this car, the caster is not adjustable, but we need to know what it is anyway. The reason we measure the caster, even though we can’t change it, is to check if it is good. We need to be within factory settings. As well, we want to make sure that the caster is balanced side to side.
To take the caster measurement we unlock the turntables and install the measuring tool into the center hub. We are using the Longacre wheel alignment tool. There is a caster button on the Longacre tool. By setting the wheel out 15 degrees, zeroing the tool, then turning in 30 degrees, we come up with the caster number. Side to side we want to only see a .5 degree difference.
What to do if the numbers are very wrong? If your caster number is out of whack, something could be bent. Re-inspect the suspension parts for any damage and replace parts as necessary.
Camber refers to the tilt of the wheel in and out from the car.
When you lower a car, the caster numbers are going to be larger. This is because as the wheel moves up into the fender, the wheel tilts in more. Before we made any adjustments we measured the camber on all four wheels. The Longacre tool will also measure camber. The camber reading is in degrees. A neutral camber is zero degrees, no in or out. Positive camber will mean the top of the wheel comes out. Negative camber means the bottom of the wheel comes out. Refer to factory numbers for your setup. Because this car is lower than stock, we expect higher negative camber.
In the front, the camber is adjusted by moving the strut towers. Move the strut in or out to achieve the desired camber. Caster and camber number go hand in hand, moving one will affect the other. Double-check your numbers before locking everything down.
In the back of the car, you adjust the camber by an offset nut. You may need two people, one to set and one to read the Longacre tool!
The toe number refers to how much the wheel points in or out looking down on the car from above. This car had worn out the inside of the driver’s tire, we expected bad toe numbers. We are not disappointed! The wheels were all over the place for toe. We have a 10mm toe out on three of the four wheels. The toe on this car is 1mm toe-in on each wheel. On this car, the wheels toe-in. That means the front side is 1mm in on each wheel, compared to the trailing edge.
To measure the toe you need to set up your strings. The string needs to be parallel to the frame of the car. On this car, the back wheels stick out further than the front wheel, but this does not mean the string does the same. The string needs to be perfectly parallel to the car frame. Remember, the numbers are very small, you need to be precise. Take the time to set up your string correctly.
We use a lightweight aluminum bar are each end of the car. We hang the bars off the hood and engine frames. The string tension also holds the bars in place. With the string set up, we can finish up our four-wheel alignment by locking in the toe numbers.
Final checks of your Four-Wheel Alignment
The test drive is the best way to check your four-wheel alignment. When you are driving the car, you should move straight down the road with the steering wheel centered. Turning should feel good, and equal on both sides. Choose a nice flat road to work the car, as well as some nice turning roads. The test drive is the funniest part of this job. Don’t forget to check your torque’s on all the suspension parts and wheel nuts before you drive off.
You may like these other easy jobs on your Porsche Boxster: