Google has some pretty good results from other guys with similar issues.
Compressor surge occurs when the compressor wheel is accelerated to a point where it is able to provide little flow for the amount pressure ratio (boost), this is shown on a compressor efficiency map as the surge or choke line on the left hand side. It tends to be particularly evident with small exhaust housing/turbine combos with large compressor wheels, I *think this has a lot to do with insufficient exhaust flow compared to the amount of air that the compressor is supplying.
Apart from backcutting the turbine blades, or going up a size in exhaust housing A/R ratio, some people have had success with machining a step in the compressor housing near the leading edge of the comp wheel's blades.... but nothing is guaranteed
Thu, 15 September 2005 12:05
