crisp;1286846 said:This is actually an interesting thread. There could be a LOT of misinformation, and ill-functioning set-ups that could be remedied with a little insight into the distinctions between several symptoms or conditions which are all being referred to with a common term (such as "flutter" and "surge") and yet do not nearly capture the subtle mechanics of what is actually happening, and there are multiple issues and equally varied and specific solutions for them. I would caution that DIFFERENT VEHICLE SETUPS and conditions created within the plumbing (manifold, etc...) MAY ACTUALLY CAUSE certain "surge" and "flutter" behavior out of the BOV, which is EXACTLY what the BOV SHOULD BE DOING when the SIGNAL PRESSURE is TELLING IT to do those things! If your SIGNAL PRESSURE is a PULSE, then the BOV SHOULD FLUTTER! That's simply VALVE RESPONSE to the signal being sent. That DOESN'T MEAN the signal pressure is what you WANT the engine to be sending!!! THIS is often the item that should be addressed when a BOV is "acting funny", or undesirably. (am I rambling?) Do you have "pressure drop" points in your IC system?
...would make a good "sticky", but who would step up and clearly define these things? Who really understands and is able to lead us?:biglaugh:
(felt pretty philosophical there for a moment...)
Those videos CLEARLY (imho) demonstrate "unfavorable" BOV-havior in the latter clips...:nono: HOWEVER, it is NOT necessarily the fault of the BOV in all casses... it COULD be a number of other factors.
I still stand by the fundamental principles that are at work here. Pressure. Generally expressed as BOOST or VACUUM (other terms available...) and how it is utilized from certain sources to provide the most "timely" and "accurate" pressure force signal on a specific "mechanism" (VALVE) to cause it to actuate relative this source signal, to produce a specific function, which is retention (compression maintained, or valve closed) or exhaustion (decompression, or valve open) with the objective being to effectuate one of these two states AND TRANSITION BETWEEN THEM in a controlled, predictable, consistent manner... with a HUGE BIAS toward accomplishing this function in as TIMELY (IMMEDIATE) and RESPONSIVE a manner as mechanically possible.
CHECK YOUR LINES
(short, good integrity with correct volume under both boost and vacuum, responsive)
CHECK YOUR SOURCE
(primary point at which desired pressure shift is available to most efficiently provide the valve with it's signal)
UNDERSTAND WHAT YOUR VALVE SHOULD BE DOING
(OPEN or CLOSE with QUICK transition)
CONSIDER THE ACCURACY OF YOUR SIGNAL SOURCE
(if it pulses, the BOV valve could be responding in kind)
...gotta get my coffee... the pot is whistling. That's BOOST!
Turbo Coffee.:biglaugh:
NOTE: I don't have any background nor formal knowledge on these things AT ALL, but I've stared at my BOV and it's plumbing for hours over the years, and considered it's functional design intent, actual behavior, and ways to effectuate "KAIZEN" or "change/better" principle of incremental optimization, and found notable improvements that lead to great performance (my opinion) under various conditions. Then again, I'm working in a moderate 15-18psi max. range, and other contributors may come into play at higher pressures with which I have no experience.
-crisp
Good post, and I enjoyed reading it. Well also look into hooking a vaccum gauge up to my source and see what it does.