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Discussion Starter · #1 ·
Hey all,

Yesterday, I finally decided to commit to doing a vacuum reduction, with the hopes of minimizing (or outright eliminating) any boost leaks I may have had. Before the reduction, even with my MBC set to max boost, I would only hit 7-8 lbs on my aftermarket gauge. I'm aware that waste gate pressure is 6-7 lbs, so Im hoping they are functioning as they should.

After finishing the reduction and replacing all the necessary lines with new 4mm line, I notice that I am still only hitting 8 lbs on the aftermarket gauge. No matter what I do, I still only get 8 lbs. In addition to this, I find that the blow-off valve (Yes, blow off valve, not bypass valve) now seems to 'blow off', or relieve pressure, a bit later than before. In the past (before reduction), as soon as I let off throttle or pushed the clutch in, I'd here the lovely "psshhh" with a high-pitched whistle. Now, when I let off throttle/push clutch in, I will get the same, albeit quieter noise most of the time, and it seems fractions of a second later than before. Has anyone ever experienced this? I have been toying with the screw on the top of the valve that lets me adjust how much pressure it needs to 'blow off', but it hasn't seemed to provide any positive effects. The more I back the screw out, the more performance I lose in terms of acceleration, since it won't hold boost as long/high.

Lastly, I have read in multiple different places that the vacuum hose that goes from the manual boost controller to the top of the y-pipe (the one with red paint on the ends) has some sort of restrictor 'pill' in it. Is this true? Is it necessary for the boost controller to function properly?

Thanks in advance

Jared

P.S.: Anyone out there with a 3S that lives in Arizona, and more specifically, Tucson? Need some new car friends :)
 

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Discussion Starter · #2 ·
Welp, I answered my own question. Apparently my bleed-style MBC was allowing pressure to go to the wastegates at any/all adjustment level. No matter how ‘open’ or ‘closed’ the MBC was, it would still allow pressure through to the wastegates. Spent $10 on a ball-and-spring style controller from amazon and now i’m magically hitting 14-15 psi no problem :D
Just figured i’d post my solution incase anyone else has been experiencing a similar problem. Check your MBCs people!
 
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