Vems Wideband AFR O2 + EGT gauge 52mm

Wideband O2 and EGT in one gauge

Vems displays the two most important reading of a turbo car at the same time: exhaust temperature and fuel mixture.

Why vems?

The Vems gauge displays precise fuel mixture and exhaust temperatures so they can be monitored and problems solved in case of bad readings. Vems is a cheap insurance for an expensive engine and is also trasferrable from car to car. An engine can take a suprisingly high amount of abuse as long as it is properly tuned - in other words getting the correct mixture and is not burning too hot.

Properties

Vems will display temperatures in either Celsius or Farenheit. Mixture is displayed as afr or lambda reading. Changing the units is as easy as pressing the button on the gauges face.

Narrowband output is available and can be configured for different signal types for different ecus. Even a custom chart is possible in case you need one.

Delivery contents

Gauge unit.

Bosch LSU4 wideband sensor.

6mm thermocouple suitable for turbo use.

Thermocouple connector.

Mounting hardware.

A long, quality harness.

Neccessary connectors.

Sensors

Wideband lambds: M18x1.5 thread. Same as 99 % of narrowband units.
EGT: 1/8 NPT (National Pipe Thread).
Sensors are also available separately:
Bosch LSU wideband sensors ja K-type thermocouple.

Thermocouple connector

It is important to connect the egt sensor with the correct polarity. The green wire is positive (+) and the white one negative (-).

Fuel mixture

Air fuel ratio (AFR) is the ratio of air and gasoline which burns in the engine. A lean (too much air) or a rich (too much fuel) ratio will at least cause increased fuel consumption, and in a worst case break the engine due to increased heat or detonation (detonation is the mixture exploding instead of burning).

Lambda 1 or 14.7 AFR on gasoline means the mixture is stochimetric, in other words optimal for burning.
Pump gas 14.7:1 (lambda1)
Ethanol / E85 9.76:1 (lambda 1)

A slightly lean mixture is good for cruise economy, and a richer is less probe to detonation and results in more power. A rich mixture also burns cooler than leaner mixtures.