Ooops, forgot to mention that that's what I did. When I switched to the Tial Q I made an adapter flange that enlarged the 1" port coming out of the aftercooler to 1.5". This was the only setup where I didn't hear flutter at high RPM shifts. But as RAIN H8R mentioned it was loud and annoying as fawk (to me) at cruising speeds. I switched back to a Tial QR which uses the same enlarged 1.5" port coming out of the aftercooler, but funnels down to a 1" at the outlet of the BOV. Its much quieter, but the flutter is back. I'm gonna live with it.

 

Thanks for the info. I was actually reading through your SOS FAQ which made me decide to vent it to atm - just wanted to make sure that I'm not experiencing anything out of the ordinary.

 

I have 2 diverter valves with independent vacuum hoses and I'm close to 500whp DynoJet. One is set to recirculate and the other (using the 3/4" port on the SOS AC) vents to atmosphere. I get no farty or flutter sound in the higher rpms.

 

I'm running this way as well.

 

any photos of the QR and SOS water box???
my now at 12.5lbs and hear alot of flutter at blow off high RPM. My tuner said this backpressure surge could hurt the blower

how noticeable it the QR flutter? faintly? its hopefully better than the stock bosh blow off

 

It’s just the undersized Bosch recirc valve being a bit overwhelmed and not being able to evacuate all the air in a clean stream, so you here it flutter. This doesn’t necessarily mean its backing up in the SC yet, but the valve being overwhelmed is a sign that you may be getting close at 10psi and any future plans of upping the boost would be smart to add a larger diverter valve or even just a second Bosch.

I run the Turbosmart which still uses the 1" port on the aftercooler, however the valve has a much larger evac port (it has two actually) on opposing ends, which open up in different stages of boost pressure (idle/Lo & Hi) Then I took the stock Bosch valve and run it over to the smaller 3/4" port on the other side of the aftercooler where the nipples is from the air pump I removed. This is enough to handle a larger NV1200 at Max Boost without any surge or flutter sound.

 

anyone try http://www.synapseengineering.com/

 

The small diverter is just not big enough once you start spinning the blower.

On the sos charged car we have here in the shop, at 13psi you could see the blower stall when we let out of the throttle and it would kick the belt off 1/2 the time. A tial Q fixed it.

 

I run dual diverter valves like s2000junky. I have no issues with my novi 1200 and I see up to 21psi at peak.