Basically the same idea. Usually guys used them when they were draggin. Go to the track open up the dump outs, Off the track you switch back to the full exhaust. In theory it was to save you the hassle of switching exhaust systems between both. It was hard to find a happy medium at times with the dump outs.


Fryguy

Man, you must be fast because you were haulin' A$$ when I passed you back there. . .