02/03/2022
neat!
As the cars running in the Pro Class at continue to get faster, we’re seeing more innovative approaches taken to optimise their performance. As the requirements for power continue to climb we’re seeing the turbo size increase. The problem with these large turbos is that we can end up dangerously close to the surge limit with some of the smaller displacement engines that are used in the likes of the Global Aircraft Services .
A novel solution to this is to incorporate a small drive-by-wire throttle body on the intercooler charge plumbing that’s controlled by the ECU. This can be used in place of a conventional blow off valve when the driver lifts off the throttle, however the more interesting use of this dbw throttle body is for anti-surge. In very simple terms, compressor surge occurs when the turbo is flowing more air than the engine is able to consume. Operating the turbo in surge conditions can result in damage to the thrust bearings and even the compressor wheel itself, but it’s also not great for engine performance. To combat this the ECU can monitor the turbo operation and then open the dbw throttle body if it starts operating in a region where surge is likely to occur.