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Old 10-05-2017, 04:27 PM   #1
DjDom
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What happens to the DISA valve with a Centrifugal Supercharger?

Hey guys,

Been really looking into putting a supercharger on my 330, and leaning more towards the centrifugal style.

However, I've been thinking, the DISA valve works by using the vacuum from the engine to open and close. If you put a centrifugal supercharger in, you're creating positive pressure in the intake, not a vacuum, therefore, the DISA doesn't have vacuum to run.

Am I correct or am I over complicating this? Lol.
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Old 10-06-2017, 08:30 PM   #2
Melbowski
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The DISA's internal reservoir has a one-way valve that only lets it take in vacuum. Even with a supercharger whenever you're off-throttle (shifting/idling/cruising) the manifold will be in vacuum to fill this reservoir which is then good to actuate roughly 3 times before requiring more vacuum to function. That said, it probably isn't going to be a problem, and since it defaults to open it won't impede your flow even if it can't receive vacuum (if you're hooning it hard and use no-lift-to-shift repeatedly; which would be at too high of RPM for it to activate anyway). Worst-case scenario it just remains open all the time, and with forced induction you likely won't be able to tell the difference since the DISA's low-end bump is mostly negated by boost (it can be used to bump low-end torque a little though, but you'd need to tune the activation points in the DME). Hope that helps
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Last edited by Melbowski; 10-06-2017 at 08:37 PM. Reason: Clarity
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Old 10-08-2017, 09:53 PM   #3
DjDom
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This makes sense.
I didn't know the reservoir actually stores some vacuum in it. Thought there was only vacuum in it as the engine creates vacuum.
Thanks for the response!
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