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Discussion Starter #1
i'm running 2 tial 50 mm "q" bov's in my new combo... based on tial's chart, my big cam motor that makes very little vacuum at idle needs a 6 psi spring. however, i'm running 2 tial "q" valves on a twin setup. should I stick with what the chart says and go with 6 psi springs in both valves? the combo has a big stall and big cam meaning once throttle is lifted the engine drops rpm quickly and proceeds to makes little vacuum. I just want to be able to slam the throttle shut and protect my turbos from surge, so what springs do y'all think??? thanks in advance!
 

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http://www.tialmedia.com/documents/BOVspc.png

Stick to the chart, same in both. Keep in mind it's not the vacuum that opens the valve. It the sudden change in pressures on both sides of the valve. While in boost it's applying the same boost to both sides of the valve equalizing the pressure. When the throttle closes it cuts off the pressure to the valves one side. Allowing it to open from the boost pressure in the charge pipe. Having the correct spring rate helps in the aid of opening the BOV at lower boost or when not quiet in boost driving around town.
 

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Discussion Starter #4
thanks for the responses guys. i am not familiar with turbo setups. i had a centri-blown combo before and ran the infamous procharger big red valve... it stayed open during idle (kinda moved up and down during idle) and would slam shut when throttle was opened and slam open when throttle was abruptly shut. it seems the tial valves are slightly different (or is it the way turbos dont make any boost without engine load) but i just want the valves to open when i slam the throttle shut to protect my turbos. my engine makes very little vacuum when throttle is shut.... i wanted a baseline spring to purchase in order to get my engine going to DETERMINE my exact vacuum reading at idle, cause i dont know that yet.
 
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