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2015+ Shelby GT350 Mustang
GT350 whipple problems
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<blockquote data-quote="JAJ" data-source="post: 15882094" data-attributes="member: 131874"><p>When I was doing my tuning for driveability, I set up a pair of analog MAP sensors (GM parts, as I recall) and plumbed them into the manifold - one ahead of the blower behind the throttle and one after the blower as a boost reading. My SCT X3 allowed me to record the analog signals along with the ECU PID's. To figure out what was going on, I measured both manifold pressures, electronic throttle position, Mass Air Flow (MAF) and LOAD. With the bypass open, the chambers are connected and both pressures are the same. When the bypass closes at 5" of vacuum, the pressures should stay the same as they were and as each other. That may sound surprising but it's pretty simple logic: the MAF and the RPM determine the post-blower pressure at the intake valves, which doesn't change just because the bypass closes. Similarly, MAF and Electronic Throttle plate position determine pre-blower pressure, and since MAF doesn't change, that pressure doesn't change either. In short, closing the bypass when there's still vacuum in the intake gets the system ready for making boost, but otherwise it should be a non-event.</p><p></p><p>Once the throttle is open far enough that you've got essentially atmospheric pressure on the inlet to the blower, you'll start producing boost. Until then, the pre-blower and post-blower pressures should be pretty much the same.</p></blockquote><p></p>
[QUOTE="JAJ, post: 15882094, member: 131874"] When I was doing my tuning for driveability, I set up a pair of analog MAP sensors (GM parts, as I recall) and plumbed them into the manifold - one ahead of the blower behind the throttle and one after the blower as a boost reading. My SCT X3 allowed me to record the analog signals along with the ECU PID's. To figure out what was going on, I measured both manifold pressures, electronic throttle position, Mass Air Flow (MAF) and LOAD. With the bypass open, the chambers are connected and both pressures are the same. When the bypass closes at 5" of vacuum, the pressures should stay the same as they were and as each other. That may sound surprising but it's pretty simple logic: the MAF and the RPM determine the post-blower pressure at the intake valves, which doesn't change just because the bypass closes. Similarly, MAF and Electronic Throttle plate position determine pre-blower pressure, and since MAF doesn't change, that pressure doesn't change either. In short, closing the bypass when there's still vacuum in the intake gets the system ready for making boost, but otherwise it should be a non-event. Once the throttle is open far enough that you've got essentially atmospheric pressure on the inlet to the blower, you'll start producing boost. Until then, the pre-blower and post-blower pressures should be pretty much the same. [/QUOTE]
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GT350 whipple problems
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