AutoMeter Carbon Fiber 52mm Mechanical Boost Gauge – 0–35 PSI | Universal | 4704

AutoMeter 4704 Carbon Fiber series 52mm mechanical boost gauge with a 0–35 PSI range. Bourdon tube movement delivers accurate, responsive boost pressure readings with no electrical connection required. 52mm diameter fits standard aftermarket gauge pods and A-pillar mounts. Includes 1/8" NPT fittings and nylon line kit. 1 lb. Ships fast across Canada and the US.

Mechanical vs Electronic — Why Mechanical

Boost gauges come in two types: mechanical (this gauge) and electronic (sensor + wiring + gauge display). Each has distinct advantages:

• Mechanical advantages: No sensor to fail. No wiring required. Immediate, real-time needle response directly proportional to boost pressure — no sensor sampling delay. Inherently accurate across the full pressure range without calibration. Simpler installation for straightforward boost monitoring applications.
• Mechanical trade-off: Requires running a physical boost line from the engine bay through the firewall to the gauge. Line integrity is critical — a failed line in the cabin is a safety concern. Routing discipline and proper firewall grommet installation are important.
• Electronic advantages: No boost line into cabin. Sensor can be located remotely. Suitable for dash-mount displays far from the engine bay. Logs data if connected to a logging system.

For most turbocharged or supercharged street builds where the gauge will be mounted in a pod close to the dash, a mechanical gauge is the simpler, more reliable choice.

Bourdon Tube Movement — Accuracy and Durability

The 4704 uses AutoMeter’s bourdon tube meter movement — the same fundamental operating principle used in industrial pressure gauges for over 150 years. A curved hollow metal tube is connected to the boost pressure source. As pressure increases, the tube straightens proportionally, moving a needle via a mechanical linkage. The accuracy and durability of a bourdon tube gauge are determined by the tube’s material, wall consistency, and the precision of the movement linkage. AutoMeter manufactures their bourdon tube movements to tight tolerances for accuracy across the 0–35 PSI range and long-term durability under repeated pressure cycling.

0–35 PSI Range — Coverage

The 35 PSI upper limit covers the majority of turbocharged and supercharged street and performance builds:

• Street turbo builds (gasoline): Most street-driven turbo cars run 10–22 PSI on pump fuel; E85 builds commonly run 25–30 PSI. 35 PSI provides headroom for high-boost E85 or race fuel applications.
• Turbo diesel: Diesel boost pressures vary widely — stock diesels typically run 20–30 PSI; modified diesels can exceed 35 PSI. Confirm your diesel build’s peak boost before ordering.
• Supercharged gasoline: Positive displacement and centrifugal supercharger builds typically run 8–18 PSI; the 35 PSI range provides comfortable headroom.

The gauge also reads vacuum (negative pressure) at idle and light throttle — useful for monitoring manifold vacuum on naturally-aspirated engines or at light load on boosted applications.

Carbon Fiber Series — 52mm

The AutoMeter Carbon Fiber series features a carbon fiber texture dial face — a clean, performance-oriented aesthetic that pairs well with carbon fiber interior trim and modern cockpit builds. The 52mm (2-1/16") gauge diameter is the universal standard for aftermarket gauge pods — compatible with virtually all single, double, and triple A-pillar pods, dash pods, and gauge clusters designed for 52mm gauges.

Installation — What’s Included

The 4704 kit includes everything required for a basic installation:

• 1/8" NPT male fitting — threads into your intake manifold, charge pipe, or boost tap
• Nylon boost line — routes from the NPT fitting through the firewall to the gauge
• Gauge-end fitting — connects the nylon line to the gauge inlet

A 1/8" NPT tap point is required on the intake manifold or charge pipe. Most aftermarket intake manifolds include one or more 1/8" NPT ports; OEM manifolds may require drilling and tapping. Route the nylon line away from heat sources (exhaust, turbo) and secure with clamps or clips. Use a firewall grommet at the firewall pass-through to protect the line.

Universal fit — 1/8" NPT tap required. Boost line firewall routing required. 35 PSI maximum — confirm peak boost. No electrical connection needed.

Specifications

• Brand: AutoMeter
• Part Number: 4704
• Series: Carbon Fiber
• Diameter: 52mm (2-1/16")
• Type: Mechanical — Bourdon tube movement
• Range: 0–35 PSI (also reads vacuum)
• Connection: 1/8" NPT
• Electrical: None required
• Includes: 1/8" NPT fittings, nylon line kit
• Fitment: Universal
• Weight: 1 lb