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Presenting a brand new approach to heat exchangers for engines, transmissions, hydraulic systems, etc. This new heat exchanger is made of only two pieces of circular extruded aluminum profiles: Core and shell. No soldering: The core and the shell is assembled by a minimum of automated work. In an oil to water cooling application, the active surface on the oil side of the core is enlarged by fins 0.2 mm thick, 0.3 mm spacing, and 3 mm high. The fins are made in unique production machines and enlarge the active surface area approximately five times compared to a conventional heat exchanger of the same dimensions. The principle utilizes the low pressure drop at laminar flow and avoids the disadvantage of low heat transfer after a certain laminar flow length. The result is approximately three times higher oil heat dissipation, combined with very low oil pressure drop, compared to conventional technique.

In order to improve fuel economy and available power, a knock detector system has been developed which controls the maximum charge pressure in the Saab 2-litre Otto Cycle Turbo engine. Compared to ignition retard knock control, the charge pressure control offers advantages in tolerance to variations in fuel octane number, full throttle fuel economy, hot spot auto ignition control, exhaust gas temperature and sensitivity to electrical noise and interference. Further, the system allows a significant temporary increase in available engine power when accelerating in normal traffic conditions. The turbocharger wastegate setting for maximum charge pressure is achieved through an integrated electronic system. The charge pressure knock control system is to a great extent “fail-safe”.