Restore Your Auto Instruments

At West Valley Instrument Specialists, Inc. in Reseda, CA, our mission is to improve and give your auto instruments a new look. We offer a variety of services, such as converting your instruments from mechanical to electronic, installing LEDs, and upgrading your original vehicles. In addition, we use auto instruments that are manufactured by trusted brands, including:

  • Alfa
  • American
  • Smiths
  • Stewart Warner
  • VDO
  • Veglia Borletti
  • Yeager

We are proud of our ability in making old vehicles look like new, as well as customizing and assisting our customers in their ongoing dash projects. Our owner, Morris Mintz, started his career in the early ‘70s with Nisonger Instruments (dedicated to Smiths instruments). Using his industry knowledge, he effectively leads our staff members, encouraging them to closely listen to our customers’ needs and provide services that meet all expectations. Today, we serve a wide range of clients, including antique and auto restorers, as well as car enthusiasts and hobbyists.

Determine Your Vehicle’s Ratio

Do you know how to determine the actual ratio of your vehicle? We outlined a list of detailed steps that will give you an accurate figure:

  • 1 Make sure that the tire pressure matches the exact factory specifications.
  • 2 Make sure that the tire pressure matches the exact factory specifications.
  • 3 Make sure that the tire pressure matches the exact factory specifications.
  • 4 Measure a distance of 52 feet and 9 1/2 inches using tape marks or chalk.
  • 5 Unscrew the speedometer head’s cable.
  • 6 Place a mark on the inner core. You can use a hairpin, paper flag, or paper clip for this.
  • 7 Drive or push your vehicle across the entire distance. Take note of the partial and full cable revolutions as you do this.
  • 8 In order to remove gear clearance, roll your vehicle toward the first marking and stop when the inner core starts to turn. Take note of which vehicle part is at the start of the line before you start counting. When the marked part goes beyond the line, stop counting.
  • 9 Perform the test three times to confirm that there is no gear slippage.
  • 10 For accurate calibration, send this test form together with the gauge.
  • 11 Please include contact information

Alternatively, you can also determine the ratio using this formula:

1680 times N divided by R
N = number of turns the inner cable makes for six revolutions of the rear wheel
R = radius in inches from the center of the hub to the ground while the car is on the ground

For example:
N= 8.50 | R= 11.25

1680 x 8.5 = 14280
14280 ÷ 11.25 = 1269

Vehicle ratio = 1269 revolutions per mile