Patent ID: 7181379

Claim:
In the testing of internal combustion engines and motor vehicles containing internal combustion engines, said engine defining an air intake portion comprising an engine air intake and crankcase and an exhaust, by leading the exhaust emissions from an engine to an exhaust dilution tunnel and drawing a sample of diluted exhaust for analysis to determine engine performance and engine emission components, the invention comprising: a system for testing said engines at various altitudes and operating temperatures by balancing a selected air pressure at engine intake, crankcase and exhaust to simulate operating conditions at the altitude represented by said selected air pressure, comprising: a. a single pressure control module for pressurizing ambient air to a selected pressure to simulate a desired altitude; b. a pressure-temperature equalization module in fluid communication with said pressure control module for receiving pressurized air from said pressure control module, said pressure-temperature equalization module comprising a pressure tight container defining a plenum and a heat exchanger for cooling or heating said pressurized air to a desired temperature; c. said pressure control module being in fluid communication with said air intake and crankcase of said engine and with said exhaust dilution tunnel for supplying air at said selected pressure to said engine air intake portion and said exhaust dilution tunnel; whereby pressure at said air intake, crankcase and said exhaust dilution tunnel is or is about equilibrated and simulates operating conditions of said engine at an altitude represented by said selected pressure.