Just an issue with words...I've never heard "dump valve" used for anything on the intake side in 45 years of working with cars...but maybe that's because I'm a Canuck?
I've always heard the term used for a vent on the exhaust system to "dump" exhaust pressure, typically bypassing cat converter and muffler -- thus no need for large-diameter (and heavy) exhaust plumbing.
...car gains 40 to 60 hp from stock, whole top end opens up, feels free-running, and it sounds like a huge vacuum cleaner....
