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Impact Failure

The failure of a part or assembly due to repeated impact or off-square seating.

Impact Hardness

The hardening of a part caused by repeated impacts.

Impact Particle Cleaning

A method of cleaning parts using air-propelled glass beads.

Impedance

The total opposition a circuit offers to the flow of current. Including resistance and reactance and is measured in Ohms. Most digital meters have 10,000,000 Ohms of impedance to protect computer circuits.

Impeller

1. A rotor or rotor blade used to force a gas or liquid in a certain direction under pressure. 2. A rotor that transmits motion such as a centrifugal pump, supercharger, turbine, or fluid coupling.

Impulse

A momentary surge in voltage or current.

Impurities

1. Any unwanted element or compound in a metal or semiconductor 2. An intentional doping element in a semiconductor.

IMRC

[1] Integrated module relay controller [2] intake manifold runner control.

IMS

An acronym for the Indianapolis Motor Speedway.

IMSA

An acronym for the International Motor Sports Association.

In

Indium An element with the atomic number of 49.

In And Out Box

A racing transmission having a neutral and single direct drive forward gear.

In The Chute

Staged for a drag race.

In-car Sensor

A term used for in-car temperature sensor.

In-car Temperature Sensor

A thermistor used in automatic temperature-control systems for sensing the in-car temperature.

In-duct Sensor

A thermistor used in automatic temperature control units for sensing the in-duct returns air temperature.

In-H2O

An acronym for inches of water column.

In-Hg

An acronym for inches of mercury.

In-lb

An English measure of torque.

In-line Engine

An engine having all its cylinders in one line or row.