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Classic Instruments Speedometer | Tachometer Interface Module
$142.95
The SN74Z has the following features when used as a Speedometer interface.

Input Source Options:
  • Three wire pulse signal generator input source
  • Built-in Vehicle Speed Sensor (VSS) input source
  • Most Tremec transmissions
  • Later model 700R4's
  • Typically a sine wave signal
  • Two wire pulse signal generator input source
  • Classic Instruments SN96 or SN95
  • Typically a sine wave signal
  • One wire ECM signals input source
  • Typically a 5 volt square wave
Output:
  • The output can be selectable between either 8000 pulse per mile or 16000 pulse per mile
  • Outputs a 12V square wave, 50% duty cycle
  • 8000 pulse per mile cruise control output
Additional Benefits:
  • Three different calibration options
  • Instant: drive 30 MPH and press the calibration button
  • Real-Time: press and the hold the calibration button to match the speedometer reading to the actual vehicle speed
  • Marked Mile: Drive a measured mile to calibrate the speedometer
  • Input signal can range from 2000-200,000 pulses per mile
  • State of the art signal averaging software that ensures smooth pointer operation, even in fluctuating signal conditions.
  • Noise-reducing, filtered power output for powered speedometer signal generators
The SN74Z has the following features when used as a Tachometer interface.

Input Source Options:
  • High Voltage Coil signal input source
  • .5-6 pulses per revolution (1-12 cylinder engine)
  • Typically the negative side of an ignition coil
  • 5-12V Square Wave signal input source
  • .5-6 pulses per revolution (1-12 cylinder engine)
  • 20%-50% duty cycle
  • Typically from an electronic ignition box or computer
  • Inductive Gear tooth sensor input source
  • Typically used in diesel applications where there is not an ignition system
  • The sensor can be mounted to the engine near the flywheel to sense the gear teeth as they rotate by
  • Can be used with 32-510 tooth flywheels, 32-510 pulses per revolution
Output:
  • Signal output
  • 12V square wave, 50% duty cycle
  • 2, 3, or 4 pulses per revolution (4, 6, or 8 cylinder)
  • 3 preset flywheel tooth settings
  • 148 tooth - Chevrolet Duramax
  • 152 tooth - 5.9L Cummins
  • 155 tooth - 7.3L Ford Powerstroke
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WARNING: Cancer and Reproductive Harm
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About Classic Instruments

Classic Instruments is a company dealing in the manufacture of gauges for vehicles. They are located in Boyne City, Michigan, United States of America. They have been in the limelight for their innovative products for 37 years now. They are the first and only company that uses micro-chip technology along with electrical instruments. The price range varies for different styles of products. They claim to not compromise on their quality.

Classic Instruments Mission Statement

The company is on a mission to provide vintage-style gauges to its customers. They are providing high-quality gauges which provide a seamless and rich experience to the buyers. Constant innovation and betterment are one of their missions while running the company towards the road to success. They are on a mission to remain the leaders in their respective industries and provide full services to their employees and company.

Classic Instruments Product Line

The first product catalog of Classic Instruments was released in 1978 that is termed as the original classic series by them. In the year 1980, their first speedometer comprising of electric adjustability was introduced. After a couple of years was the year when mechanical speedometers were discontinued. In 1987, the first-ever programmable electric speedometer was unveiled. since then the success story is continuously growing and the company was able to achieve a lot of awards for its contribution to the industry. In 2021, Classic Instruments release a full cluster set for vintage ford cars. The company has been continuously paving the road to success by their innovative unique ideas and perfect quality products.

Classic Instruments at Vivid Racing

Vivid Racing is honored to be the distributor of their products on our website. You can find their individual gauges, direct-fit gauge sets, and universal gauge sets in various sizes and model.

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