Information courtesy of Borgeson Universal.
Steering System Design
Often the steering system is designed late in the building process. We recommend that the steering be mocked up at the time the engine and exhaust components are installed. Positioning of the column, shafts, and u-joints with respect to the engine, exhaust and steering box early on can help in selecting the correct parts. With our wide selection of u-joints, shafts, and vibration reducers, any system can be designed or modified to result in a car that is not only safe, but a pleasure to drive. Keeping a system simple is the best course, but even a system with up to 10 u-joints can be designed as long as the proper phasing and supports are used. Remember to use a support bearing if more than two joints are used.
Shaft Support Placement
Any time more than two universal joints are used in a system, a shaft support is required to prevent the shafts from looping. In a system with 3 u-joints, one support is required. For each additional u-joint, an additional support will be needed. In a 3 joint system it is best to locate the shaft support as close to the center u-joint as possible. If one of the shafts is significantly longer than the other, it is best to locate the support on the longer shaft.
Vibration Reducer Placement
Vibration reducers can substantially reduce, and even eliminate annoying road vibration from being transmitted to the steering wheel. Location of the reducer in a system is very important in order to take full advantage of its effects. In a two joint system, the vibration reducer can be installed at either end without any loss of effectiveness. In a system with one or more shaft supports however, the vibration reducer should be located on the column side of the supports. A shaft support located on the steering column side of a vibration reducer can pick up vibration, bypass the reducer, and transmit the vibration to the steering wheel.
A great way to free up some much needed leg room in your street rod is by using a shorty column. This moves the steering column up under the dash and gives you much more leg/pedal space resulting in a much more comfortable ride.
Steering Column Length and Column Drop Size
Before determining the column length, it is important to have your seat and pedals in the final locations. Using a pie tin tacked to a wooden dowel is an excellent way to decide on steering column position and length. With one person sitting in the car and holding the "steering wheel" in position, another person can take measurements of column length and position. Keep in mind, our traditional style steering wheels are flat, while our Forty Style and Banjo wheels are dished approximately 4". This is also the perfect time to determine how much drop you'll need to put the column in a comfortable driving position. Measure from the mounting surface on the dash to the center of the steering column. This is the length of the drop you will need.
Steering Box Installation Angle
One thing frequently overlooked when building or modifying a car is the position of the steering box. Steering boxes are often positioned with the input shaft level creating a much more complex steering linkage. A great way to simplify your steering linkage is to position the steering box with the input shaft angled up toward the steering column.
The steering box ratio is the relationship between input motion and output motion. The ratio is expressed as 24:1, 22:1, 16:1, etc. For example, in a 24:1 ratio box, the pitman shaft rotates one degree for every 24 degrees of input shaft rotation. The higher the first number, the more input shaft rotation is required to get the same amount of output shaft rotation. Dividing the first number in the ratio by four, gives the number of turns lock to lock.
Pitman Arm Length
Steering speed can be adjusted by box ratio or pitman arm length. The longer the pitman arm, the quicker the steering will be. That is, a longer pitman arm means less steering wheel movement is required to produce the same amount of front wheel movement. So if you are looking to speed up or slow down the steering, changing the pitman arm is an easy way to do it.
Determine splined shaft length with two u-joints:
1. Measure the distance from the end of the column to the box/rack (Dimension C).
2. Subtract 3" from this measurement.
3. Order the next even size shaft (Dimension B).
Note: We stock stainless and polished stainless shafting in 1/4" increments up to 24"
EXAMPLE If "C" is 18"
Published Dec 7th, 2015
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