Boost sag? No, you don't need EBC.
#23
Boost Pope
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To clarify a tad, I've re-drawn the two charts above to show what's happening both at the compressor outlet (blue line) and after the intercooler (red line), just in case anybody is having trouble visualizing it.
In the first case, we are taking our reference from point A. So even though it appears that boost is dropping off (as we perceive it from the perspective of the manifold) the MBC is in fact doing its job.
Having moved the MBC pickup to point B, we merely change which point in the system is stable.
In both cases, there is a point in the system at which equilibrium is reached. But in the first case, that point is one that we don't particularly care about.
In the first case, we are taking our reference from point A. So even though it appears that boost is dropping off (as we perceive it from the perspective of the manifold) the MBC is in fact doing its job.
Having moved the MBC pickup to point B, we merely change which point in the system is stable.
In both cases, there is a point in the system at which equilibrium is reached. But in the first case, that point is one that we don't particularly care about.
Last edited by Joe Perez; 09-04-2012 at 05:19 PM. Reason: Local image embeds
#24
Boost Pope
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We are in preliminary negations with DreamWorks, I'm just not real happy about their insistence on Eugene Levy as the voice of the intercooler.
This is old, old knowledge, and just basic fluid dynamics, really. Seems like it's just one of those things that isn't obvious until somebody points it out. Hell, even I needed reminding (by Abe) a few years ago.
#27
That's the problem with old knowledge like this, everyone assumes everyone else already knows it. I haven't seen this topic brought up here in a long time but there have been a number of people with droop complaints.
Now if there was a simple and cheap a solution for over-boosting we'd really have something!
#29
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Sorry for my stupidity, don't mean to muck up a good thread... but what kind of stress (if any) does this put on the turbo? Especially for the guys running 18-20psi. I can imagine that the difference in pressure between the TB and the compressor is pretty large at that amount of boost. Wouldn't the cfm required to keep some peoples max boost push the turbo pretty far out of it's efficiency range?
#30
Sorry for my stupidity, don't mean to muck up a good thread... but what kind of stress (if any) does this put on the turbo? Especially for the guys running 18-20psi. I can imagine that the difference in pressure between the TB and the compressor is pretty large at that amount of boost. Wouldn't the cfm required to keep some peoples max boost push the turbo pretty far out of it's efficiency range?
#31
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FRT, If you have a large enough intercooler you won't experience as much pressure drop across it at higher flow rates and your turbo won't be as likely to be out of its efficiency range. One of the problems I see is that people often use intercoolers that are sized for little peashooter turbos and 5 to 8psi factory turbo setups instead of the flow rates they actually aspire to run. One should aim for both great IATs and low pressure drop by going large if you really are trying to maximize your efforts. Ideally the air coming out of your intercooler should be as close to ambient temperature as possible. It is hard to do that with a tiny intercooler.
#32
+1 for a video release.
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#37
<Noob question>
"Using all-silicone tube? (***.) Well, just drill a hole in the colid-side end tank of the IC itself. Anywhere is fine so long as it's after the IC core, and before the throttle body."
Why a different place for silicone? Should one use Vac line another type instead?
</Noob Question>
"Using all-silicone tube? (***.) Well, just drill a hole in the colid-side end tank of the IC itself. Anywhere is fine so long as it's after the IC core, and before the throttle body."
Why a different place for silicone? Should one use Vac line another type instead?
</Noob Question>
#38
<Noob question>
"Using all-silicone tube? (***.) Well, just drill a hole in the colid-side end tank of the IC itself. Anywhere is fine so long as it's after the IC core, and before the throttle body."
Why a different place for silicone? Should one use Vac line another type instead?
</Noob Question>
"Using all-silicone tube? (***.) Well, just drill a hole in the colid-side end tank of the IC itself. Anywhere is fine so long as it's after the IC core, and before the throttle body."
Why a different place for silicone? Should one use Vac line another type instead?
</Noob Question>