Rob Beck 13T compressor inlet question?

[anyonebutme]

Surge FTW. When you let off, most (actually all because nobody seems to set them right thinking it's supposed to be closed at idle) aftermarket CBPVs don't release enough air and the rest stalls the compressor and blows out the intake, blowing off the intake pipe if it's not tight. Wouldn't surprise me at all if this was the base cause for a lot of people's smoking on decel problems with stock style PCV systems, 2 psi in the crankcase is more than enough to push oil past turbo seals when letting off. Just a random thought.

[Chris@Rvengeperformance]

if you have open atmosphere bov and a draw through maf you have to set it to be closed at idle or you will be drawing in unmetered air.

[anyonebutme]

False. At idle air continually blows OUT the BOV, not in. Even at idle the turbos are putting out way more CFM than the IAC is letting past the closed throttle, think about it for a second. If you still don't believe me, remove the BOV, start the car, and put your hand over the hole, there is really no state where air can get sucked in with our relatively tiny turbos. Open the throttle, vac drops and BOV closes. At startup, not enough vac and BOV is closed, ect.

Will you have to tune it out, yes, but it's doable as I've done it. You either deal with one problem or deal with another, no such thing as a free lunch when running those valves. Ditched my SSQVs for an EVO CBPV and couldn't be happier.

[Chris@Rvengeperformance]

in or out the point is I want to meter the air coming into my engine. It is up to you I guess, but it won't work out of the box the way you suggest setting it up.

Thanks for the explanation though it made sense once I remembered that there is only vacuum after the throttle plate. That also explains why the too loose of a spring on my Tial right now causes the car to run rich on off throttle coast down decelerations instead of lean like you'd expect.

[blindmist]

I have an eBay BOV that is an imitation of the RFL. Works great for the past 3 years some how. I guess I just really lucked out. It still holds 25psi just fine. I have never blown off my pre-turbo pipes.