Boost control solenoid issue after install

s300 and SManager software questions & answers
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Spunkster
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Joined: Fri Sep 20, 2002 5:06 pm
Location: Hondata

Post by Spunkster »

? The minimum boost is determined by the wastegate spring. The boost controller will not be able to reduce boost, but can only raise boost above the minimum level.

? The maximum boost is limited by the exhaust back pressure opening the valve against the wastegate spring, even with no pressure differential on the wastegate diaphragm. The exhaust back pressure increases with engine speed, so it is common to see a drop in boost at high rpm.

? Boost creep is when the boost rises at high rpm despite the wastegate being fully open. Boost creep is caused by using a wastegate valve which is too small, or (more commonly) placing the wastegate off center in the exhaust manifold so that it does not effectively reduce exhaust back pressure from all cylinders.

? A drop in boost at high rpm occurs without a boost controller because the progressively increasing exhaust back pressure open the wastegate earlier as the rpm rises. Changing the position of the wastegate pressure source often eliminates this problem.
thudreem
Posts: 50
Joined: Fri Nov 21, 2003 5:24 pm

Post by thudreem »

Spunkster wrote:? The minimum boost is determined by the wastegate spring. The boost controller will not be able to reduce boost, but can only raise boost above the minimum level.

? The maximum boost is limited by the exhaust back pressure opening the valve against the wastegate spring, even with no pressure differential on the wastegate diaphragm. The exhaust back pressure increases with engine speed, so it is common to see a drop in boost at high rpm.

? Boost creep is when the boost rises at high rpm despite the wastegate being fully open. Boost creep is caused by using a wastegate valve which is too small, or (more commonly) placing the wastegate off center in the exhaust manifold so that it does not effectively reduce exhaust back pressure from all cylinders.

? A drop in boost at high rpm occurs without a boost controller because the progressively increasing exhaust back pressure open the wastegate earlier as the rpm rises. Changing the position of the wastegate pressure source often eliminates this problem.
I understand all of this. BUt your telling e to run a lighter spring with I'm going to be 3X what my spring is rated for.. DO you have any other recommendations?
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