I run two of them.
They work great. (Custom upper pipe, there are photos at 7MPower.) Mine's the beater looking 88T with the really old photos. (I don't have that engine anymore, or those wheels, but I'm still running the same IC pipes I built a few years ago.)
Basicly I used the stock intake accordian hose, and mounted the second BOV into the crankcase vent opening. When both BOV's vent, they recirculate high pressure air back into the turbo and help keep it spooled up. I used 1" pipe for the valve ports on the intake upper pipe, so it's built for maximum flow potential.
It has held up to 27.2psi so far. (Sphinchter moment passing 3 or 4 semi trucks, a few RV's and some cars/trucks, figure 7 to 10 vehicles in a slow moving line, I'm going 130ish at this point, and around comes the corner is another RV in my lane!!! I mashed the gas, and for some reason, the dang waste gate did not regulate my boost, and it spiked causing detonation, two broken spark plugs and there was no way I could lift and slow down at the moment, so I had to "detonate" it for a few hundred feet more to complete the pass.... When I lifted and shifted into 5th, at well over 140mph, the engine died... but caught again when I let out the clutch.... LOL)
No other damage other than the two spark plugs. (Coatings rule.)
BOV's held the pressure, no problems.
You have to have them plumbed in the right way however. I see photos on here all the time where guys are complaining they suck, leak and are crap. Then you look at the photos, and they have the BOV plumbed backwards. They are designed to leak under vac, it provides a short cut to your throttle when your off boost. (Look at it, the BOV is a short path to the TB from the intake air.) I belive my nice low speed, no boost throttle response is due to the extra flow of the second bov.
When plumbed right, the bov's actually hold themselves shut under pressure, can can't be opened untill vac is applied to the diaphram and opens the valve. (The intake pipe pressure is pushing the valve closed, only the instant vac in the manifold applied to the other side of the diaphram when you snap the throttle closed opens the BOV against all the pressure holding it closed.)
Have fun, these valves are less than 35.00 from the parts depot. (Web based parts supplier.)
