It's a mixed bag of opinions on the Hemco. But my own personnel experience with a Hemco was very positive. I changed up from a stock throttle body and plenum to a 62 mm throttle body and a 62 mm Hemco. Boost went from 18# to 23# the car had been running consisent 12.0s and the next time out with only these changes ran 11.78. next time out at the same boost. Just my experience yours may differ.