GM has filed a patent for a sequential twin-turbo system that uses a new bypass valve design said to optimize exhaust flow to the turbines of both turbochargers. GM Inside News discovered the new patent at the U.S. Patent and Trademark Office (USPTO) website.
According to the description, the exhaust manifold features two outlets with one directing exhaust gases to the turbine of the high-pressure turbocharger, while the second exhaust manifold outlet directs exhaust gases to the turbine of the low-pressure turbocharger via a connecting channel. Additionally, exhaust gas exiting the high-pressure turbine is directed to the inlet of the low-pressure turbine.
The new bypass system features two throttle valves located on the same spindle mounted perpendicular to each other. With the throttle valves mounted on the same plane, one valve opens to direct exhaust gas flow to one of the turbochargers while the other valves simultaneously blocks exhaust gas flow to the other turbocharger. The vehicle ECU (electronic control unit) sends a signal to the spindle’s actuator to rotate the throttle valves based on rpm and load.
GM says the new design allows engineers to optimize exhaust gas flow to both turbines without the compromises of traditional sequential turbocharger systems. Additionally, the system could utilize a variable-geometry turbine or a fixed-geometry turbine on the high-pressure turbo.
With throttle valves located on the same spindle, it greatly simplifies the design by eliminating the need for a second actuator and associated parts.
On paper, the design looks so simple we’re surprised nobody has come up with it before. What do you think of GM’s approach to sequential turbo systems, and what vehicle do you think it might show up in first? Tell us in the comments below.
Source: U.S. Patent and Trademark Office via GM Inside News
- Google Plus
GM Patents Sequential Turbocharger System With Unique Bypass Valve