Went to the track with some people yesterday. One guy had an SRT-4. He reved the engine and when he let off it backfired.
I said, "Does your blow off valve vent to the atmosphere? or recirculate back into the intake stream?"
He said, "Both."
"Uh huh, really both?"
"Well no, the stock one did recirculate, but I have an aftermarket one that vents to the atmosphere."
"Oh, 'cause when you revved before, you backfired or something."
"Yeah that's just the exhaust, because they don't come with a muffler."
"Wow."
![Confused :?](./images/smilies/icon_confused.gif)