Im finishing up my remote roots blower on my LS1 build and havent been able to decide on which pressure relief system to use. The ford M90's do not have a built in bypass or any other similar system, so anything used will need to be added

For the racecar, it was easy. I put two BOVs before the MAF. It only saw two throttle positions, WOT and 0%, the BOVs simply kept the intake couplers from blowing apart

This build is a bit different, its a street car and Im not out for max power. I intend for it to hold together under low/no boost situations which make up 95% of the drive time

Bypass valve. Compressor output vented to the blower inlet to be recirculated
Pros:
Cheap, common on OEM turbo cars
Same style system used for OEM SC cars
Quiet
MAF located anywhere I choose, pre or post SC

Cons:
Slightly more complicated because external tubes are required, additional ports welded on etc

Atmospheric BOV
Pros:
Cheap
Easy to install

Cons:
Some sound awful and the good sounding ones will get annoying before too long
MAF location limited, BOV must be before the MAF


Which system sounds better for me?

 

it sounds to me like you would be happier with the bypass valve.

As far as sound getting annoying if 95% of your driving will be at low to no boost levels you will not even hear the bov since the pressure of the air getting realesed will be small.
Im just a sucker for bov sounds ive had and tried on my cars almost all the ones that are out

 

Um, actually the ford setup does have a bypass, a small, about 1" or so diameter butterfly style valve operated by a pressure diaphragm/canister.

 

It's built into the cast alum ductings before and after the blower, neither of which I have. The case itself has no bypass installed like all other Eaton units found on normal cars

 

yea, I've always just cut them off and then welded them to where I needed to put it...