FWIW, I just pulled my e-vac system off. It's not the hot setup for street use. And, the valves WILL open at very low rpms if the vacuum is enough. My valves open even in the garage just warming the car up. This will pull oil out while the oil is cold and thick. My car would leave puddles under the tailpipes when cold. Yes, I had baffles in the valve covers and yes I have 40 series flowmasters and tailpipes out the back.